WDH WDH

your AIR, OUR PASSION 

H E A T P U M P S 

01/2010

Company Profi le 

Applications 

INDEX 

2 

4 

What is a heat pump? 

How the heat pump works 

The source, the user 

Types of heat pumps 

Air to water heat pumps; Water to water heat pumps 

Ground source heat pumps; Hybrid heat pumps 

Effi ciency of the heat pump 

Why using a heat pump 

The using of primary energy 

Applications of the heat pumps 

Domestic hot water (D.H.W) 

How to design a heat pump 

Monovalent Systems 

Solution with ground source heat pump 

Solution with ait to water heat pump LZT series 

Monovalent systems with electric integration 

Selection software 

What is the E.V.I. technology 

6 

6 

7 

7 

8 

9 

10 

10 

11 

12 

12 

13 

14 

15 

15 

16 

18 

20 

LZT 

High effi ciency air to water heat pumps with E.V.I compressor 

22 

LZH 

High effi ciency air to water heat pumps with Scroll HP compressor 

28 

CZT 

WZT 

WZH 

WDH 

LWZ 

LPH 

High effi ciency air to water heat pumps with E.V.I compressor 

High effi ciency air to water heat pumps with E.V.I compressor splitted version 

Ground source heat pump 

Ground source heat pump 

Hybrid high effi ciency air to water heat pumps with E.V.I compressor 

Swimming pool air to water heat pumps 

34 

40 

46 

52 

60 

66 

Heat pump systems 

Installation description 

70 

86

The Company 

HIDROS 

HIDROS was born in 1993 as a trading company involved in the market of dehumidifi cation and humidifi cation of the air. 

Quite soon the necessity to satisfy the great demand of special products, in a wide variety of applications and capacities, lead the company 

in 2001, to develop and produce its own production. 

Today HIDROS with its qualifi ed staff, designs, develops and tests dehumidifying systems and air handling units based on refrigerant 

cycle, heat pumps and water chillers. 

2

Hidros catalogue includes standard dehumidifi ers with capacities from 25 to 3000 l/24h, heat pumps and water chiller with cooling and 

heating capacities from 5 to 900 kW. At this range HIDROS adds a wide range of tailor made machines to meet any customer requirement. 

High competence and enthusiasm are the other essential elements that guarantee quick, fl exible and adequate solutions. 

HIDROS 

Where we are 

BOLZANO 

BELLUNO 

UDINE 

TRENTO 

PORDENONE 

GORIZIA 

BRESCIA 

VICENZA 

VERONA 

TREVISO 

TRIESTE 

PADOVA 

VENEZIA 

MANTOVA 

ROVIGO 

From Milan airport: 

take the A4 motorway (in the direction to Venice) - leave the motorway at the Padova Est exit 

From Bologna airport: 

take the A13 motorway (in the direction to Padova), then continue on the A4 (in the direction of Venice) - leave the motorway at the 

Padova Est exit 

From Venice airport: 

take the A4 motorway (in the direction to Milan) - leave the motorway at the Padova Est exit 

From Treviso airport: 

take the A27 motorway (in the direction to Venice) - at the Venezia-Mestre junction take the A4 motorway (in the direction of Milan) - 

leave the motorway at the Padova Est exit 

From Verona airport: 

take the A4 motorway (in the direction to Venice) - leave the motorway at the Padova Est exit 

From the Padova Est exit, to HIDROS: 

take the Tangenziale Est (eastern bypass, also called Corso Argentina) and follow the directions for Chioggia, continue along the bypass 

for around 5 km until reaching the turnoff at via G. Marconi (Statale Piovese, SS516), follow the directions for Piove di Sacco - continue 

for around 12 km, once having passed through the town of Vigorovea, after around 1 km, turn right and follow the directions for Brugine, 

after around 800 metres (before the traffi c lights), turn right into Via dell’Industria; HIDROS is on your left at number 5. 

3 

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Applications 

HIDROS 

Heat Pump WDH/RV in two sections 152-162 model with refrigerant R134a. 

Heat Pump air to water model LDKHP 300 SP. Heat Pump air to water model LZT 36. 

4

HIDROS 

Heat Pump water to water model WDH 260. Heat Pump water to water model WDH/RV 090. 

Heat Pump air to water model LZT 14. Heat Pump air to water model LZH 06. 

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WHAT IS A HEAT PUMP? 

HIDROS 

A heat pump is a device that moves heat 

from one location (called the 'source') to 

another location (called the 'user'), 

using energy. 

Basically, a heat pump operates under the 

same principles of an air conditioner, but in 

the reverse way. 

Compressor 

Evaporator 

Condenser 

Expansion device 

HOW THE HEAT PUMP WORKS 

The heat pump is equipped with a 

refrigerant circuit and uses a special fl uid 

(called refrigerant fl uid) that, depending on 

the temperature and pressure conditions in 

which it is working, it can be in gaseous or 

liquid state. 

The refrigerant circuit is made by: 

• The compressor; 

• The condenser (also called user heat 

exchanger); 

• The expansion valve; 

•The evaporator (also called source heat 

exchanger). 

The refrigerant fl uid, in its gaseous state, 

is pressurized and circulated through the 

system by the compressor. 

On the discharge side of the compressor, 

the hot and highly pressurized gas is 

cooled in a heat exchanger, the condenser, 

until it condenses into a high pressure, 

moderate temperature liquid. The 

condensed refrigerant fl uid then passes 

through a pressure-lowering device (the 

expansion valve). This device then passes 

the low pressure, (almost) liquid refrigerant 

to another heat exchanger, the evaporator 

where the refrigerant fl uid evaporates into 

gas via heat absorption. The refrigerant 

then returns to the compressor and the 

cycle is repeated. 

In such a system it is essential that the 

refrigerant fl uid reaches a suffi ciently high 

temperature when compressed. Similarly, 

the fl uid must reach a suffi ciently low 

temperature when allowed to expand and 

in particular, the pressure difference must 

be great enough for the fl uid to condense 

at the hot side and still evaporate in the 

lower pressure region at the cold side. The 

greater is the temperature difference, the 

greater is the required pressure difference, 

and consequently more energy is needed 

to compress the fl uid. 

Thus as with all heat pumps, the energy 

effi ciency (amount of heat moved per unit 

of input work required) decreases with 

increasing temperature difference. 

Heat pumps are also available in reversible 

versions; this means that during winter 

season they produce heating, during 

summer period they can produce cooling. 

This process is carried out by the use of a 

4 way reversing valve; This valve switches 

between "heating mode" and "cooling 

mode" by an electric signal given via the 

unit controls. By switching the valve, the 

freon fl ows one way to produce hot water 

and changes over via the control signal to 

produce chilled water. 

6

THE SOURCE, THE USER. 

THE SOURCE 

The external mean from which the energy is 

absorbed is called cold source. In the heat 

pump the refrigerant fl uid absorbs heat 

from the cold source in the evaporator. The 

LZT, WZT and LPH heat pumps use the 

ambient air as cold source, that’s why they 

are identifi ed as Air-to–water heat pumps. 

The WZH and WDH heat pumps use water 

as cold source and they are identifi ed as 

water to water heat pumps. 

THE USER 

The water to be heated is called user. In 

the heat pump the user is the condenser 

in which the refrigerant fl uid transfers 

(releases) the thermal energy absorbed 

from the source. The thermal energy can 

be transferred to the building by a heating 

system normally using: 

Fan coils, 

Radiators; 

Underfl oor heating systems. 

HIDROS 

TYPES OF HEAT PUMPS 

There are different types of heat pumps, classifi ed by the type of the source; the main types are: 

• AIR TO WATER HEAT PUMPS; 

• WATER TO WATER HEAT PUMPS; 

• GROUND SOURCE HEAT PUMPS; 

• HYBRID HEAT PUMPS; 

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HIDROS 

• AIR TO WATER HEAT PUMPS; 

Air is used as the cold source; it has the 

advantage of being available at all times; when 

the ambient temperature is close and below 

0°C, it is necessary to incorporate a defrost 

system into the source heat exchanger. 

The aspect that should be considered in the air 

to water heat pump, infact, is the occurrence 

of a problem with ice on the source coil during 

those ambient temperatures. 

As a fail-safe to this, the heat pump will melt this 

ice (defrost cycle) on it's own, but it requires the 

switching of the valve to allow the Freon to run 

in reverse direction. After successfully melting 

the ice that builds up on the outside coils, the 

heat pump will then reverse the valve again 

and consequentely the refrigerant cycle.The 

internal coils are hot,the external ones are cold, 

while the heat pumps produce hot water again. 

The defrost cycle absorbs energy from the heat 

pump, energy that is lost, and not put into the 

hot water circuit, temporarily reducing the heat 

pumps heating output. In most cases we can 

estimate that, in major European countries the 

energy lost during defrost cycle may vary from 

5 to 13%. 

• WATER TO WATER HEAT PUMPS; 

Water is used as cold source; this solution 

grants the best performances without the 

variations caused due to the external climatic 

conditions (typical of the air to water heat 

pumps); but the water is not always available, 

and it requires an additional cost due to the 

external hydraulic connections. 

8

• GROUND SOURCE HEAT PUMPS; 

Cold source is used from the energy stored in 

the ground. The thermal energy (cold source) 

is "absorbed" from the ground by pipes, 

inside which brine, mixed with water glycol, 

is circulating. The brine can be fi tted either 

vertically a horizzontally, designed to absorb 

the max possible energy. 

The horizontal pipes are normally buried at 

1 or 1,5 meters depth to avoid variations in 

the performances due to different ambient 

conditions and to keep the advantages of the 

solar irradiation. It is normally necessary, in 

these executions to have an underground 

piping equal to 2-3 times than the ones in the 

surface area of the building to be heated. 

In case of vertical pipes, they are normally 

designed down to 100 meters deep to obtain, 

as average, between 4 to 6 kW each one. 

The ground source heat pumps have the 

advantage of a constant C.O.P. and heating 

capacity without the variations caused due 

to the external climatic conditions, but they 

present also a sensible cost due to the drilling 

to be done. 

HIDROS 

• HYBRID HEAT PUMPS; 

In these versions, there are the advantages 

of the air to water heat pumps (in terms of 

economicity and installation) and also the 

higher effi ciencies typical of the water to water 

heat pumps. 

These units are always working as air to water 

units and they are equipped with fi nned coil and 

fans. 

The units, are also using a second heat 

exchanger, water source, that is used in case of 

low ambient temperatures (for example below 

0°C). 

In these conditions, then, using a small water 

source or a small ground probe, it is possible 

to keep high the C.O.P. of the unit even with 

severe ambient conditions. In this way we can 

obtain an excellent ratio between costs and 

performances. 

9 

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HIDROS 

EFFICIENCY OF THE HEAT PUMP 

During its operation the heat pump: 

•“Absorbs” electricity in the compressor; 

•“Absorbs” thermal energy from the source 

(air or water); 

• Releases thermal energy in the user heat 

exchanger (water). 

value of 3 to 5. This means that for 1 kWh 

of electric input energy , the unit will supply 

from 3 to 5 kWh of thermal energy to the 

user. 

The C.O.P. may vary, depending on the 

temperature at which the heat is transferred. 

The colder is the source temperature, the 

lower is the C.O.P. 

The main advantage of the heat pump is the 

capacity to supply more energy (thermal) 

than the one required for its operation 

(electrical). 

The effi ciency of a heat pump is measured 

by the coeffi cient of performance “C.O.P.” 

that is the RATIO between the thermal 

energy supplied to the user and the electric 

input power absorbed by the unit. 

The C.O.P. is variable depending on the 

type of the heat pump and the working 

conditions, and it is generally around a 

Input Power 

1 kWh 

Heating Capacity 

4 kWh 

WHY USING A HEAT PUMP 

The graphic shows what is the use of 

energy in a typical north European region 

(i.e. Germany): 

The national energetic load is divided as 

follows: 

• 77,8% Heating; 

• 10,5% Domestic hot water; 

• 6,6% Home appliances; 

• 3,7% Cooking; 

• 1,4% Lighting. 

It is evident how the reduction of the 

energy used for heating (is much more 

predominant compared to the other uses) 

allows a massive reduction of the energy 

bill in different countries. 

The heat pump is far more effi cient than 

any other heat source available in the 

market. Where C.O.P’s between 3 and 5, 

the energy used compared to a typical gas 

or oil system is from 3 to 5 times less. 

This means that not only it gives running 

saving but also all other benefits which 

include: 

• Low emission of greenhouse gases like 

CO2; 

•Use of electricity, available anywhere; 

• Use of renewable energies; 

• No need of fuels, gas, oil tanks, 

chimneys; 

• No environmental pollution; 

•In case the electricity used by the heat 

pump is produced by photovoltaic 

panels , we have an ideal system, with 

environmental impact of ZERO. 

77,8 % 

Heating 

10,5 % 

Domestic hot water 

6,6 % 

Home appliances 

3,7 % 

Cooking 

1,4 % 

Lighting 

10

THE USE OF PRIMARY ENERGY 

The diagrams below show the use of primary energy by the different heating system available on the market. 

167W + 27W 

3W 

HIDROS 

100W 

Electric heating 

297W 

103W 

14W 

11W 

111W 

Oil 

125W 

100W 

11W 

8W 

Natural Gas 

119W 

111W 

100W 

57W + 9W 

1W 

34W 

67W 

Air to water heat pump 

C.O.P. 3 

100W 

33W 

100W 

43W + 7W 

1W 

26W 

75W 

Water to water heat pump 

C.O.P. 4 

76W 

25W 

100W 

11 

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The use of heat pumps reduces the use of primary energy compared to other heating systems showing a massive reduction of CO2 

emissions; 

HIDROS 

Heating system 

Used primary energy percentage 

Electric heating (297%), 

Oil (125%), 

Natural Gas (120%). 

Air to water heat pump (100%). 

Water to water heat pump (76%). 

• Heat pumps are the heating system of the future; (easy to maintain, efficient, environment respectful); 

• The heat pump can be used for heating, cooling and domestic hot water production; 

• Because of their efficient performances, many users have already heat pumps, widely used in North Europe 

countries 

• The price of electricity remain quite stable, on the contrary of the gas. This allows a correct planning of 

investment. 

• Once installed, the heat pump does not require maintenance. 

APPLICATIONS OF THE HEAT PUMPS 

The heat pumps are now commonly used both in residential, commercial buildings and in the service industry as an alternative to the 

ordinary systems of heating and cooling using boilers and water chillers. As a matter of fact the same unit is able to produce heating in 

winter and cooling in summer thanks to a simple valve, which changes the functions of evaporator and condenser (reversible type). The 

application of the heat pump for heating and cooling is much more effi cient and the pay back period is shorter compared to a heating only 

application. The heat pump, anyway, can also be used for the production of residential heating and of the domestic water only. 

DOMESTIC HOT WATER (SW) 

HIDROS heat pumps are able to produce hot water up to 55÷63°C(depending on different versions) that allow the installation of the units in 

all applications where domestic hot water is required.In this case, it is necessary to use tanks bigger than those used in the normal boilers 

since the water temperature stocked doesn’t normally exceed 45-50°C. The average domestic hot water quantities at 45°C are reported 

in the following table: 

N°User 

D.H.W. 

(lt/24h) 

N°User 

D.H.W. 

(lt/24h) 

N°User 

D.H.W. 

(lt/24h) 

N°User 

D.H.W. 

(lt/24h) 

1 70 2 140 3 190 5 270 

12

HOW TO DESIGN A HEAT PUMP 

The correct design of the heat pumps is extremely 

important in the calculation of the 

total effi ciency of the heating system; An 

oversized heat pump could create comfort 

problems in the room due to wide pendulations 

of the hot water (and having a high 

economic impact), while an undersized 

heat pump could create important reduction 

in the effi ciency of the system due to 

the necessity of integration with external 

sources (like electric heaters or boilers). 

It is clear that, an excellent heat pump 

combined to a bad heating system brings 

anyway to a general bad result, confi rming 

then the necessity of a correct combination 

heat pump/heating system. 

In general, we can assume that, every °C 

less in the hot water temperature corresponds 

to an average C.O.P. increase of 

about 2-2,5% (even higher in the water to 

water units) with important consequents in 

the effi ciency of the whole system and the 

relative energy saving. 

The underfl oor heating systems, from this 

point of view, are extremely interesting since 

they allow the operation in heating with 

water temperatures around 30÷38°C, while 

radiators or fan coil systems require higher 

temperatures (around 50°C) with inevitable 

reduction of the general C.O.P. 

In line of principle, heat pump systems 

are designed with a maximum water outlet 

temperature at 55°C. In case higher temperatures 

are required (for example, restructiring 

of old buildings where it is not possible 

to replace the old heating elements), it has 

to be considered the integration of the heat 

pump with other energy sources (electric 

heaters or boilers) especially at low ambient 

conditions. 

In case of water temperature lower than 

55°C, heat pumps normally do not need 

integration with other energy sources and 

its use is to be taken into consideration only 

for economic or fi nancial evaluations that 

we will discuss in the next pages. 

HIDROS 

Some examples: 

Heat pump LZT14T @: Ambient temperature: 2°C 

Water temperature 35°C C.O.P. 3,8 



Heat pump WDH 50 @: Source water temperature: 10°C 




Today, the main solutions with heat pumps available on the market are: 

• Monovalent systems; 

• Monovalent systems with electric integration; 

• Bivalent systems. 

In this issue, we will not talk about bivalent systems (which include the use of other energetic sources besides the electric one) and we 

will focus on the 2 fi rst systems: 

13 

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HIDROS 

MONOVALENT SYSTEMS 

In general, with monovalent systems are intended those applications where it is not necessary to integrate the heating capacity produced 

by the unit. The heat pump supplies the 100% of the heating capacity required by the building. 

The design of the heat pumps in the monovalent systems is done by taking the heating capacity of the unit in the minimum ambient 

conditions. 

Example: 

Location: Stuttgart (Germany) 

This location has the following climatic trend (see below graphic): 

Ore 

600 

500 

400 

300 

200 

100 

0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 

(°C) 

Ambient temperature °C -30 -29 -28 -27 -26 -25 -24 -23 -22 -21 -20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 

Hours/Year 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 12 11 11 24 

Ambient temperature °C -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 

Hours/Year 20 38 27 29 45 74 141 171 214 338 426 421 329 395 430 332 345 343 345 353 366 

Ambient temperature °C 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 

Hours/Year 368 437 400 382 350 345 279 215 197 146 111 97 61 50 34 17 12 6 4 3 0 

Ambient temperature °C 33 34 35 36 37 38 39 40 

Hours/Year 0 0 0 0 0 0 0 0 

From the graphic it is evident that the location has a minimum ambient temperature of -14°C for 6 hours per year. In case we have a 

building which has a heat loss of 9 kw at -5°C ambient, with an indoor temperature of 20°C, located in Stuttgart, we will have a heat loss 

(calculated in accordance to UNI12813*) represented by the following table. 

* Refer always to the load laws in force in the country in which the heat pump is installed. 

14

SOLUTION WITH GROUND SOURCE HEAT PUMP 

The main characteristic of the ground source and/or water to water heat pumps is the one of keeping constant the heating capacity and 

the C.O.P. at different ambient conditions; this aspect allows an optimal unit sizing which allows costant and high C.O.P., since it’s not 

infl uenced by the external temperature. 

20 

(kW) 

HIDROS 

15 

Heating capacity WZH09 

10 

5 

Building Heat Loss 

0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 

(°C) 

In this case, the ground source heat pump which satispies the required capacity is the model WZH09. It has a heating capacity of 12,9 

kw with source water temperature 0°C and user water outlet 35°C. 

SOLUTION WITH AIR TO WATER HEAT PUMP LZT SERIES 

If we install, in the same building, an air to water heat pump (LZT or WZT series), the trend of the heating capacity becomes the following: 

(kW) 

35 

Ambient temperature: Heat Loss Heating capacity WZH09 

0°C 7 kW 12,2 kW 

-5°C 9 kW 12,2 kW 

-14°C 12,2 kW 12,2 kW 

30 

25 

Heating capacity LZT 21 

20 

15 

10 


5 

0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 

(°C) 

Ambient temperature: User Heat Loss Heating capacity LZT21 

0°C 35°C 7 kW 17,8 kW 

-5°C 35°C 9 kW 16,0 kW 

-14°C 35°C 12,2 kW 12,9 kW 

15 

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HIDROS 

In this case, if we intend to use a monovalent 

system, we should select an LZT21 

that, at -14°C ambient temperature, produces 

a heating capacity of 12,9 kW. 

The selection of the LZT21, anyway, even 

being technically correct, is not economically 

and energetically interesting, since it 

involves an OVERSIZED unit, clearly too 

big for the remaining period of the year. 

The use of the LZT21, also involves a bigger 

water pump, bigger pipe diameters and 

the unit could result noisy and having not 

compatible dimensions. 

The above example shows the main difference 

between a ground source heat pump 

and an air to water heat pump; it consists 

on the different heating capacity when the 

ambient temperature varies. 

While the ground source heat pump (or water 

to water) has a constant source temperature 

and a consequent constant heating 

capacity, the air to water heat pump shows 

a decisive variation of the heating capacity 

when the ambient temperature varies. 

This characteristic could have negative 

infl uence if the unit is installed in locations 

with severe ambient conditions (very cold) 

while could be positive if the unit is installed 

in warmer locations, where the use of an 

air to water heat pump instead of a ground 

source one, should be more effi cient. 

Generally speaking, in a the installations 

with air to water heat pumps, it is not used a 

monovalent system but it is preferred a monovalent 

system with electric integration. 

MONOVALENT SYSTEMS WITH ELECTRIC INTEGRATION 

Normally, it’s considered a monovalent system 

with electric integration a plant where 

the heating capacity generated by the heat 

pump is supported, for short periods, by 

electric heaters. 

In this case the heat pump supplies just a 

part of the heating capacity required by the 

building, a value that, to obtain a good compromise 

costs/benefi ts, it is normally calculated 

in a way that the unit should be able 

to satisfy the building heat loss for 90-95% 

of the time of winter season. 

The design of the heat pumps in the monovalent 

systems with electric integration is 

done excluding the minimum ambient temperatures 

present for 5% to 10% of the time 

of the winter season. 

Specifi cally, the selected location shows 

the following diagram: 

Ambient temperature: N°hours year: Winter season 

-14°C a 20°C 8219 Total winter season 

-14°C a +5°C 3162 38,4% 

-14 a 0°C 1161 14,0% 

-14 a -5°C 223 2,70% 

-14 a -10°C 64 0,77% 

-14°C 6 0.07% 

If we consider the possibility of using an air 

to water heat pump in the same building of 

the previous example we will proceed in the 

following way: 

A minimum ambient temperature, to which 

the heat pump can satisfy, by the building 

has to be established. 

This because the period of time during 

which the heat pump will be undersized can 

not be more than 5/10 %. 

The below graphic shows that the ambient 

temperature “goes” from -14°C (minimum 

winter ambient temperature) to -5°C, 

during a period of time of 223 hours per 

year, corresponding of 2,7% of the total 

winter season. 

In the same way, we can see that the 

location shows an ambient temperature 

below 0°C for 1161 hours, equivalent to the 

14% of the total winter season. 

If we report in the below diagram the heating 

capacities of the sizes LZT10T, 14T and 21, 

we can notice the following trends: 

16

(kW) 

35 

30 

25 

Heating capacity LZT21 

HIDROS 

20 

15 

Heating capacity LZT14T 

10 

Heating capacity LZT10T 

5 


0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 

(°C) 

The intersection point between the segments identify the minimum ambient temperature at which the selected heat pump is able to satisfy 

the heat loss of the building; It's necessary to integrate the heating capacity of the heat pump with electric heaters with lower ambient 

temperatures. 

Using a Heat Pump: 

Using an LZT21 the balance point will be at -14°C; 

Using an LZT14T the balance point will be at -8°C; 

Using an LZT10T the balance point will be at -2°C; 

The correct selection, in this case, will be the LZT14T that, with a balance point of -8°C, shows the best compromise between costs and 

benefits. 

17 

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HIDROS 

SELECTION SOFTWARE 

For a right selection of the heat pump, Hidros has developed and makes available to installers a sofi sticated software which permits to 

calculate all the parameters of the system: 

• Intersection point heat pump/installation; 

• Season thermal energy produced by the heat pump; 

• Calculation of the thermic power for the hot domestic water; 

• Energy losses for thefrosting (only air to water heat pump); 

Project reference: 

Reference location: 

Building heat loss @ -5°C 

Number of persons 

Heat pump kWh electric cost 

Integration electric heater kWh cost 

Heat pump model: 

HEAT PUMP SEASON EFFICIENCY SIMULATION 

Heat pump type 

Hidros srl 

Sede legale: via della Croce Rossa 32/2 35129 (Pd) Italy 

Sede operativa: via dell’industria 5, 35020 Brugine (Pd) Italy 

VAT IT 03598340283 Codice fiscale 03598340283 

Tel. +39 049 9731022 Fax. +39 049 5806928 

Web:www.hidros.it E-mail: info@hidros.it 

Germany - Stuttgart 

Indoor temperature 

°C 

kW 9,0 Source inlet temperature (Dt=3°C) °C 

n. 4 Hot water temperature 

°C 

€/kWh 0,11 Ambient temperature with off installation ≥°C 

€/kWh 0,11 Domestic hot water quantity per person l 

Domestic hot water temperature 

LZT14T 400/3 

°C 

Domestic water inlet temperature °C 

√ 

Air/Water 

Water/Water 

Ground source 

20 

… 

35 

16 

50 

50 

10 

BUILDING HEAT LOSS / HEATING PRODUCED BY THE HEAT PUMP 

The graphic shows the building energy loss (in kwh including DHW energy - red line), compared to the heating capacity developed by the heat 

pump (in kwh- black line). The graphic includes the heat loss of the heat pump due to the defrost cycle. 

(kWh) 

3500 

3000 

2500 

2000 

1500 

1000 

500 

0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 

(°C) 

AMBIENT TEMPERATURE TREND 

In the table it's underlined the number of hours / year of the selected location, in relation to the ambient temperature (Dry Bulb). 

Ambient temperature (°C) 

Hours (h) 


Hours (h) 


Hours (h) 


Hours (h) 


Hours (h) 

-30 -29 -28 -27 -26 -25 -24 -23 -22 -21 -20 -19 -18 -17 -16 -15 

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

-14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 

6 12 11 11 24 20 38 27 29 45 74 141 171 214 338 426 

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 

421 329 395 430 332 345 343 345 353 366 368 437 400 382 350 345 

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 

279 215 197 146 111 97 61 50 34 17 12 6 4 3 0 0 

34 35 36 37 38 39 40 

0 0 0 0 0 0 0 

Total hours 8760 

18

• Electric energy with integrations; 

• Operating costs; 

• Installation season C.O.P.. 

Please contact the company for the availability of the software. 

HIDROS 

HEAT PUMP SEASON EFFICIENCY SIMULATION 

Hidros srl 

Sede legale: via della Croce Rossa 32/2 35129 (Pd) Italy 

Sede operativa: via dell’industria 5, 35020 Brugine (Pd) Italy 

VAT IT 03598340283 Codice fiscale 03598340283 

Tel. +39 049 9731022 Fax. +39 049 5806928 

Web:www.hidros.it E-mail: info@hidros.it 

Building heat loss 

Building heat loss + DHW 

Domestic hot water request (DHW) 

Seasonal energy produced by the HP 

Seasonal heat pump input energy 

Integration electric energy 

Integration electric power 

kwh 34530 Total winter season 

h 7183 

kwh 37925 Heat pump hours operation 

h 3303 

kwh 3395 Heat loss due to defrost cycle 

kw 6226 

kWh 35850 Heat loss due to defrost cycle 

% 16,8% 

kwh 11343 Electric energy cost of the heat pump € 1247,7 

kwh 1464 Integration electric energy cost 

€ 161,0 

kw 3,2 Total seasonal electric energy cost € 1408,7 

Seasonal heat pump 

efficiency 

C.O.P. 

3,2 

Seasonal heat pump efficiency + 

integration heating 

C.O.P. 

2,9 

AMBIENT TEMPERATURE TREND 

In the graphic it's underlined the number of hours / year of the selected location, in relation to the ambient temperature (Dry Bulb). 

400 

300 

h 

200 

100 

(°C) 

0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 

BALANCE POINT 

The graphic shows the balance point between the power building heat loss + DHW and the heating capacity produced by the HP. 

kW 

40,0 

30,0 

20,0 

10,0 

(°C) 

0,0 

-30 -25 -20 -15 -10 -5 0 5 10 15 20 

19 

www.hidros.it

WHAT IS THE E.V.I. TECHNOLOGY 

HIDROS 

HIDROS LZT and WZT heat pump units 

starting from model 10 are supplied 

with compressors equipped with E.V.I. 

technology, a versatile method of improving 

system capacity and effi ciency. The vapour 

injection technology consists of injecting 

refrigerant vapour in the middle of the 

compression process, to boost capacities 

and effi ciencies signifi cantly. Each scroll 

compressor used in the LZT and WZT units 

is similar to a two-stage compressor but 

with built-in interstage cooling. In the above 

diagram are shown the main phases of the 

refrigerant cycle in a E.V.I. unit. 

P 

Pi 

Pm 

i 

m+i 

h 

Compressor 

i 

Injection 

Condenser 

m + i 

Expansion 

valve 

Evaporator 

m 

The high stage consists of extracting 

a portion of the condenser liquid and 

expanding it through an expansion valve 

into a heat exchanger acting as a sub 

cooler. The superheated vapour is then 

injected into an intermediate part in the 

scroll compressor. 

The additional sub cooling increases the 

evaporator capacity. The bigger it's the 

pressure ratio between condensing and 

evaporating pressures, the more signifi cant 

is the performance compared to any other 

compressor technology. This technology 

allows the LZT and WZT units to produce 

hot water up to 63°C with the possibility 

to operate down to -15°C ambient 

temperature. 

20

The graphics below show the trend of the coeffi cient of performance C.O.P. in 2 conditions: hot water production at 40°C and 55°C. The 

lines show different types of scroll compressors today available on the market also using different refrigerant gases: R407C, R410a. It is 

evident that the working range of R407C is wider than R410A ones, especially in case of low ambient conditions. 

C.O.P 

5 

Water produce at 40°C 

C.O.P 

4 

Water produce at 55°C 

HIDROS 

4,5 

3,5 

4 

3 

3,5 

3 

2,5 

2,5 

2 

2 

-20 -15 -10 -5 0 5 10 


The effi ciency of the EVI compressors at 

low ambient conditions is about 25% higher 

than the standard scroll compressors; 

Such differences become even much more 

evident in applications with quite high hot 

water temperatures (i.e. when domestic 

hot water is required). In this case we 

can also notice that the operational limits 

of a standard scroll compressor are not 

suffi cient to produce the required hot 

water temperature (55°C) at ambient 

temperatures below 5°C. 

1,5 

-20 -15 -10 -5 0 5 10 


The below graphic shows the operation 

range of the EVI scroll compressors supplied 

in the LZT and WZT units; at -15°C ambient 

the water outlet temperature is still 55°C; 

this allows the heat pump to be installed in 

much more diverse ambient conditions. 

Water Temperature °C 

65 

60 

55 

50 

45 

40 

35 

30 

25 

20 

-20 -15 -10 -5 0 5 10 15 20 25 30 


Units equipped with scroll compressors 

with vapour injection technology E.V.I. with 

freon R407C. 

Units equipped with scroll compressors 

HP (high performance) without the vapour 

injection system E.V.I. freon R407C. 

Units equipped with standard scroll 

compressors with freon R407C. 

Units equipped with standard scroll 

compressors with freon R410A. 

21 

www.hidros.it

LZT 

High efficiency air to water heat pumps with E.V.I. 

compressors 

LZT 

-15°C 

+63°C 

E.V.I. 

C.O.P.≥4,1 

The high effi ciency LZT heat pump series have been 

especially designed for application with radiant fl oor heating 

systems or in those applications where it is necessary to 

have the highest maximum effi ciency in heating mode. The 

units have been optimized for heating mode, they are able 

to produce water up to 63°C and they can operate down to 

-15°C ambient temperature. 

The LZT units are available in the 2 pipes version and in the 

SW6 version, with 4 pipes. 

Both the versions can produce domestic hot water; the LZT 

through the activation of an external 3-way-valve, the SW6 

one, through a suitable hydraulic circuit for the domestic hot 

water which allows its production independently from the unit 

version. 

All models are supplied standard with reverse cycle valve for 

cold water production. 

OTHER VERSION 

• LZT 2 pipes reversible standard. 

• LZT/SW6 4 pipes unit able to produce hot and cold 

water at the same time on two independent hydraulic 

circuits. 

ACCESSORIES 

• 

• 

• 

• 

• 

• 

• 

• 

• 

LS low noise version. 

Pumps contacts (user pump, domestic hot water 

pump). 

Electronic soft starter. 

Rubber vibration dampers. 

Spring vibration dampers. 

Refrigerant pressure gauges. 

Remote control panel. 

Serial interface card RS 485. 

condensate discharge drip tray with antifreeze heater. 

22

LZT 

Model LZT - LZT/SW6 10M 10T 14M 14T 21 26 

Heating capacity (EN14511) (1) kW 9,6 9,6 13,9 13,9 19,6 26,5 

Total input power (EN14511) (1) kW 2,3 2,3 3,4 3,2 4,5 6,4 

COP (EN14511) (1) W/W 4,2 4,2 4,1 4,3 4,4 4,1 



COP (EN14511) (2) W/W 3,5 3,5 3,5 3,7 3,6 3,4 



COP (EN14511) (3) W/W 3,2 3,4 3,2 3,3 3,5 3,1 

Cooling capacity (EN14511) (4) kW 11,3 11,3 15,4 15,5 21,4 30,9 


EER (EN14511) (4) W/W 3,8 3,8 3,8 3,9 3,8 3,8 



EER (EN14511) (5) W/W 3,3 3,6 3,2 3,3 3,3 3,0 

Power supply V/Ph/Hz 230/1/50 400/3+N/50 230/1/50 400/3+N/50 

Max input current A 25,5 8,0 33,0 12,0 19,5 22,0 

Peak current A 100,0 45,0 162,0 60,0 106,0 101,0 

Fans n° 1 1 2 2 2 2 

Compressors n°/tipo 1/Scroll with EVI 

Sound power level (6) dB (A) 69 69 71 71 75 79 

Sound pressure level (7) dB (A) 41 41 43 43 47 51 

Water pump (optional) kW 0,2 0,2 0,3 0,3 0,45 0,55 

Water tank (optional) l 40 40 60 60 60 180 

LZT 

Model LZT - LZT/SW6 36 46 52 72 82 92 



COP (EN14511) (1) W/W 4,5 4,5 4,5 4,1 4,1 4,1 



COP (EN14511) (2) W/W 3,6 3,7 3,6 3,4 3,4 3,5 



COP (EN14511) (3) W/W 3,4 3,5 3,5 3,1 3,2 3,1 



EER (EN14511) (4) W/W 3,9 3,7 3,8 3,6 3,5 3,5 



EER (EN14511) (5) W/W 3,2 3,1 3,2 2,9 2,9 2,9 

Power supply V/Ph/Hz 400/3+N/50 

Max input current A 26,0 31,1 39,7 50,0 58,0 71,2 

Peak current A 129,0 170,0 121,0 155,0 199,0 237,0 

Fans n° 2 2 2 2 2 2 

Compressors n°/tipo 1/Scroll with EVI 2/Scroll with EVI 

Sound power level (6) dB (A) 79 79 82 82 82 83 

Sound pressure level (7) dB (A) 51 51 54 54 54 55 

Water pump (optional) kW 0,55 1,0 1,3 1,3 1,5 1,5 

Water tank (optional) l 180 300 300 300 300 300 

Performance refer to the following conditions: 

(1) Heating: Ambient temperature 7°C DB, 6°C WB, water temperature 35/30°C. (2) Heating: Ambient temperature 7°C DB, 6°C WB, water temperature 45/40°C. 

(3) Heating: Ambient temperature -7°C DB, -8°C WB, water temperature 35/30°C. (4) Cooling: ambient temperature 35°C, water temperature 23/18°C. 

(5) Cooling: ambient temperature 35°C, water temperature 12/7°C. (6) Sound power level according to ISO 3746 (LS version). 

(7) Sound pressure level at 10 mt from the unit in free fi eld conditions direction factor Q=2, according 

to ISO 3746 (LS version). 

23 

www.hidros.it

LZT 

LZT 

FRAME 

All LZT units are made from hot-galvanised 

thick sheet metal, painted with polyurethane 

powder enamel at 180°C to ensure the 

best resistance against the atmospheric 

agents. The frame is self-supporting 

REFRIGERANT CIRCUIT 

The refrigerant gas used in these units is 

R407C. The refrigerant circuit is made by 

using international primary brands components 

and according to ISO 97/23 concerning 

welding procedures. The refrigerant 

circuit includes: 

sight glass, fi lter drier, double thermal expansion 

valves (one for cooling mode, one 

for heating mode) with external equalizer, 

4 way reverse cycle valve, one way valves, 

liquid receiver, Schrader valves for 

maintenance and control, pressure safety 

device (according to PED regulation). Models 

starting from 10 are also supplied with 

an AISI316 stainless steel heat exchanger 

used as economizer and additional expansion 

valve for refrigerant vapour injection. 

COMPRESSORS 

The compressors used are high performance 

scroll type, supplied with a special scroll 

design which enhances the effi ciency of the 

refrigerant cycle at low ambient conditions. 

Starting from size 52, the compressors are 

in tandem execution. Units starting from 

model 10 are also supplied with economizer 

and vapour injection system, a versatile 

method of improving system capacity and 

effi ciency. The vapour injection technology, 

consists of injecting refrigerant vapour in 

the middle of the compression process, to 

boost capacities and effi ciencies signifi cantly. 

Each scroll compressor used in the LZT 

units is basically similar to a two-stage compressor 

but with built-in interstage cooling. 

The highest stage consists of extracting a 

portion of the condenser liquid and expanding 

it through an expansion valve into a 

heat exchanger acting as a sub cooler. The 

superheated vapour is then injected into 

an intermediate port in the scroll compressor. 

The additional sub cooling increases 

the evaporator capacity. The bigger is the 



the performance gains with this system 

compared to any other compressor tech- 

nology. The compressors are all supplied 

with crankcase heater and thermal overload 

protection by a klixon embedded in 

the motor winding. They are mounted in a 

separate chamber in order to be separated 

from the air stream. The crankcase heater 

is always powered when the compressor 

is in stand-by. The inspection is possible 

through the frontal panel of the unit that allows 

the maintenance of the compressors 

even if the unit is working. 

SOURCE HEAT EXCHANGER 

The source heat exchangers are made of 

copper pipes and aluminium fi ns. The diameter 

of the copper pipes is 3/8” and the 

thickness of the aluminium fi ns is 0,1 mm. 

The tubes are mechanically expanded into 

the aluminium fi ns to improve the heat exchange 

factor. The geometry of these condensers 

guarantees a low air side pressure 

drop and then the use of low rotation (and 

low noise emission) fans. The source heat 

exchangers can be protected by a metallic 

fi lter to be installed on request. 

USER HEAT EXCHANGERS 

The user heat exchangers are made of AISI 

316 stainless steel braze-welded plates 

type. The use of this kind of heat exchangers 

allows a massive reduction of the refrigerant 

charge of the unit compared to the 

traditional shell-in-tube evaporators and 

also a reduction of the overall dimensions 

of the unit. The user heat exchangers are 

factory insulated with fl exible close cell material 

and can be equipped with antifreeze 

heater (optional). Each heat exchanger is 

provided with a temperature sensor as antifreeze 

protection. 

FANS 

The fans are axial type with aluminium aerofoil 

blades. They are statically and dynamically 

balanced and supplied complete of 

the safety fan guard according to EN 60335. 

They are mounted on the unit frame by interposition 

of rubber vibration dampers. The 

electric motors are all at 6 poles (about 900 

rpm). The motors are directly driven with an 

integrated thermal overload protection. The 

protection class of the motors is IP 54. 

MICROPROCESSORS 

All LZT units are supplied standard with microprocessor 

controls. The microprocessor 

controls the following functions: regulation 

of the water temperature, antifreeze protection, 

compressor timing, compressor 

automatic starting sequence (if more than 

one compressor is present), alarm reset. 

The control panel is supplied with display 

showing all operational icons. The microprocessor 

is set for automatic defrost (in 

case of operation in severe ambient conditions) 

and for summer/winter change over. 

The control is also able to manage the program 

of thermic shock against legionella, 

integration with other thermic sources (electric 

heaters), solar panels etc, control and 

management of a modulating valve and, of 

the domestic circuit pump. Upon request 

any microprocessor can be connected to 

a BMS system for the remote control and 

management. The technical department is 

available to study, together with the customer, 

different solutions using MODBUS. 

ELECTRIC BOX 

The electric box is made according to electromagnetic 

compatibility norms CEE 73/23 

and 89/336. The accessibility to the board is 

possible after removing the front panel of the 

unit. In all LZT units is installed, standard, 

the compressors sequence relay which disables 

the operation of the compressor in 

case the power supply phase sequence is 

not the correct one (scroll compressors in 

fact, can be damaged if they rotate reverse 

wise). The following components are also 

standard installed: main switch, magneticthermal 

switches (as a protection of pumps 

and fans), compressors fuses, control circuit 

automatic breakers, compressor contactors, 

fan contactors, pump contactors. 

The terminal board is supplied with voltage 

free contacts for remote ON-OFF , winter/ 

summer change over and general alarm. 

CONTROL AND PROTECTION DEVICES 

All units are supplied with the following 

control and protection devices: Return user 

water temperature sensor, antifreeze protection 

sensor installed on the user outlet 

water temperature, return and supply, high 

pressure switch with manual reset, low 

pressure switch with automatic reset, high 

pressure safety valve, compressor thermal 

overload protection, fans thermal overload 

24

LZT 

protection, pressure transducer (used to 

optimize the defrost cycle and the fan speed 

depending on the ambient conditions), 

fl ow switch. 

OTHER VERSIONS 

LZT/SW6 UNIT WITH INDEPENDENT 

DOMESTIC HOT WATER PRODUCTION 

This version is suitable to produce 

domestic hot water: the unit is supplied 

with an additional heat exchanger used as 

condenser for the domestic hot water which, 

is independent from the operation mode of 

the unit. The activation of the additional 

heat exchanger is done automatically by the 

microprocessor control when the domestic 

hot water temperature measured by the 

sensor is lower than the required set point. 

This unit allows the production of cold and 

hot water at the same time independently. 

This version is supplied with return/supplied 

domestic hot water sensors and advanced 

control panel with specifi c software able to 

manage the operation 

priorities. 

VERSIONS 

LZT / A1 HIGH EFFICIENCY HEAT PUMP 

WITH INTEGRATED HYDRAULIC KIT 

The LZT heat pumps can be delivered 

as option, with a built in hydraulic kit that 

includes: 

Water tank in different sizes (depending on 

the size of the unit), factory insulated with 

fl exible close cell material and prepared 

for the installation of antifreeze kit (option). 

The water tank is installed on the hot water 

outlet water side to minimize the inevitable 

fl uctuations in the water temperature due to 

the compressors starts and stops. 

Water pump, centrifugal type, suitable 

for chilled water operation. The pump is 

directly controlled by the microprocessor 

that controls its correct operation. In the 

hydraulic circuit are also present the 

expansion vessel, the safety valve and the 

eventual manual valves with fi ttings. 

LZT/LS LOW NOISE VERSION 

This version includes the complete 

acoustic insulation of the unit (compressor 

+ heat exchangers vanes) with compressor 

jackets and insulating material made with 

high density media and the interposition of 

heavy bitumen layer. 

OPERATION LIMITS 

LZT 

65 

60 

55 

Water temperature production(°C). 

50 

45 

40 

35 

30 

25 

20 

-20 -15 -10 -5 0 5 10 15 20 25 30 

Ambient air temperature (°C). 

LZT 2 PIPES VERSION. 

LZT/SW6 4 PIPES VERSION. 

25 

www.hidros.it

LZT 

LZT 

Versions LZT - LZT/SW6 Codice 10M 10T 14M 14T 21 26 

Main switch 

Compressor automatic switch 

Flow switch 

Evap/condens pressure control by transducer and fan speed control 

Fresh air temperature probe for set-point compensation 

Specifi c software for operation priorities 

Remote ON/OFF digital input 

Summer/Winter digital input 

A1 Hydraulic kit (tank and pump) 

A1ZZ 

A2 Hydraulic kit (tank and 2 pumps) A2ZZ – – – – – – 

A1NT Hydraulic kit (pump only) 

A1NT 

A2NT Hydraulic kit (2 pumps only) A2NT – – – – – – 

A0NP Hydraulic kit (with tank, without pump) AONP – – – – – – 

LS Low noise version 

LS00 

Rubber vibration dampers 

KAVG 

Evaporator antifreeze heater (basic version only) 

RAEV 

Antifreeze kit (only for A versions) 

RAES 

Integrative electric heater kit 

RIAO 

Refrigerant pressure gauges 

MAML 

Electronic Soft starter 

DSSE 

Remote control panel 

PCRL 

Condensate discharge drip tray with antifreeze heater 

BRCA 

Coil protection mesh with metallic fi lter FAMM – – – – – 

Serial interface card RS485 with MODBUS protocol 

INSE 

Standard, Optional, – Not available. 

LZT 10M÷10T LZT 14÷21 

Mod. A (mm) B (mm) C (mm) Kg 

06/06A1 989 1103 380 95/148 

08/08A1 989 1103 380 104/163 

10M/10MA1 989 1103 380 118/179 

10T/10TA1 989 1103 380 120/181 


14M/14MA1 1323 1203 423 127/207 

14T/14TA1 1323 1203 423 133/212 

21/21A1 1424 1453 473 390/550 

26

LZT 

Versions LZT - LZT/SW6 Codice 36 46 52 72 82 92 

Main switch 


Flow switch 







A1ZZ 

A2 Hydraulic kit (tank and 2 pumps) A2ZZ – 


A1NT 

A2NT Hydraulic kit (2 pumps only) A2NT – 

A0NP Hydraulic kit (with tank, without pump) AONP – 


LS00 


KAVG 


RAEV 


RAES 


RIAO 


MAML 


DSSE 


PCRL 


BRCA 

Coil protection mesh with metallic fi lter 

FAMM 


INSE 


LZT 

LZT 26÷36 LZT 46÷82 

LZT 92 


26/26A1 1406 1870 850 350/510 

36/36A1 1406 1870 850 390/550 

46/46A1 1759 2608 1105 660/810 


52/52A1 1759 2608 1105 710/880 

72/72A1 1842 2608 1105 725/895 

82/82A1 1842 2608 1105 810/980 

92/92A1 1842 3608 1105 1070/1280 

27 

www.hidros.it

LZH 

High efficiency air to water heat pumps with HP 

compressor 

LZH 

-10°C 

+55°C 

C.O.P.≥4,1 

The high effi ciency air to water heat pump series LZH have 

been especially designed for application with radiant fl oor 

heating systems or in those applications where it is necessary 

to have the highest maximum effi ciency in heating mode. The 

units have been optimized for heating mode. They are able 

to produce water up to 55°C and they can operate down to 

-10°C ambient temperature. 

The LZH units are available in the 2 pipes version and in the 


Both the versions can produce domestic hot water; the 

LZH through the activation of an external 3-way-valve, 

while the SW6 ones through a separate hydraulic circuit 

specifi cally designed for the domestic hot water production. 

The SW6 versions are able to produce domestic hot water 

independently from the unit operation mode. 


cold water production in summer. 


• LZH 2 pipes reversible standard. 

• LZH/SW6 4 pipes unit able to produce hot and cold 


circuits. 

ACCESSORIES 

• 

• 

• 

• 

• 

• 

• 

• 

• 



pump). 







Condensate discharge drip tray with antifreeze 

heater. 

28

LZH 

Model LZH - LZH/SW6 06 08 10M 10T 14M 

Heating capacity (EN14511) (1) kW 6,6 8,7 11,0 11,1 15,5 

Total input power (EN14511) (1) kW 1,6 2,1 2,5 2,5 3,7 

COP (EN14511) (1) W/W 4,1 4,1 4,4 4,4 4,2 



COP (EN14511) (2) W/W 3,3 3,3 3,5 3,5 3,4 



COP (EN14511) (3) W/W 3,0 3,1 3,3 3,3 3,0 

Cooling capacity (EN14511) (4) kW 6,9 9,6 11,9 11,9 17,2 


EER (EN14511) (4) W/W 3,3 3,8 3,8 3,8 3,8 



EER (EN14511) (5) W/W 2,7 3,3 3,3 3,4 3,1 

Power supply V/Ph/Hz 230/1/50 400/3+N//50 230/1/50 

Max input current A 15,1 17,2 21,6 7,8 30,6 

Peak current A 58,5 77,0 98,0 47,0 152,0 

Fans n° 1 1 1 1 2 

Compressors n°/tipo 1/Scroll HP 1/Scroll HP 

Sound power level (6) dB (A) 68 68 69 69 71 

Sound pressure level (7) dB (A) 40 40 41 41 43 

Water pump (optional) kW 0,13 0,13 0,2 0,2 0,3 

Water tank (optional) l 40 40 40 40 60 

LZH 

Model LZH - LZH/SW6 14T 21 26 36 46 



COP (EN14511) (1) W/W 4,3 4,5 3,8 4,2 4,3 



COP (EN14511) (2) W/W 3,5 3,6 3,4 3,5 3,5 



COP (EN14511) (3) W/W 3,2 3,3 3,1 3,2 3,3 



EER (EN14511) (4) W/W 3,8 3,9 3,3 3,7 3,6 



EER (EN14511) (5) W/W 3,1 3,3 2,6 3,0 2,9 



Peak current A 66,0 75,8 101,6 129,6 169,6 

Fans n° 2 2 2 2 2 

Compressors n°/tipo 1/Scroll HP 











29 

www.hidros.it

LZH 

LZH 

FRAME 

All LZH units are made from hot-galvanised 




agents. The frame is self-supporting with 

removable panels. All screws and rivets for 

outdoor installations are in stainless steel. 

The colour of the units is RAL 9018. 










for heating mode) with external equalizer, 4 

way reverse cycle valve, one way valves, 

liquid receiver, Schrader valves for maintenance 

and control, pressure safety device 

(according to PED regulation). 

COMPRESSOR 


scroll type, supplied with a special 

scroll design which enhances the effi ciency 

of the refrigerant cycle at low ambient conditions. 

The compressors are all supplied 


protection by a klixon embedded in the 

motor winding. The crankcase heater is always 

powered when the compressor is in 

stand-by. The inspection is possible through 

the frontal panel of the unit that allows 

the maintenance of the compressors even 

if the unit is working. 









guarantee a low air side pressure 


low noise emission) fans with a decrease 

of the noise. The source heat exchangers 

can be protected by a metallic fi lter to be 

installed on request. 














protection. 

FANS 












All LZH units are supplied standard with microprocessor 





automatic starting sequence, alarm reset. 



is set for automatic defrost (in case 

of operation in severe ambient conditions) 

and for summer/winter hot water change 

over. The control is also able to manage 

the program of thermic shock against legionella, 

integration with other thermic sources 

(electric heaters), solar panels etc, control 

and management of a modulating valve 

and, of the domestic circuit pump. 

Upon request any microprocessor can be 

connected to a BMS system for the remote 

control and management. The technical 

department is available to study, together 

with the customer, different solutions using 

MODBUS protocols. 

ELECTRIC BOX 

The electric box is made according to 

electromagnetic compatibility norms CEE 

73/23 and 89/336. The accessibility to the 

board is possible after removing the front 

panel of the unit. In all LZH units is installed, 

standard, the compressors sequence 

relay which disables the operation of the 

compressor in case the power supply phase 

sequence is not the correct one (scroll 

compressors in fact, can be damaged if 

they rotate reverse wise). The following 

components are also standard installed: 

main switch, magnetic-thermal switches 

(as a protection of pumps and fans), compressors 

fuses, control circuit automatic 

breakers, compressor contactors, fan contactors, 

pump contactors (if present). The 

terminal board is supplied with voltage free 

contacts for remote ON-OFF , winter/summer 

change over and general alarm. 






water temperature, high pressure switch 

with manual reset, low pressure switch with 

automatic reset, high pressure safety valve, 

compressor thermal overload protection, 

fans thermal overload protection, pressure 

transducer (used to optimize the defrost 

cycle and the fan speed depending on the 

ambient conditions), fl ow switch, weather 

compensated external air sensor. 


LZH/SW6 UNIT WITH DOMESTIC HOT 

WATER PRODUCTION 




condenser for the domestic hot water that, 

is independently from the operation mode 

of the unit. The activation of the additional 










manage the operation priorities. 

30

LZH 

VERSIONS 

LZH / A1 UNIT WITH HYDRAULIC KIT 

INTEGRATED 

The LZH heat pumps can be delivered 


includes: 







fl uctuations in the water temperature due 

to the compressors starts and stops. The 

installation of the water tank on the hot 

water outlet water side keeps constant, for 

a period of time, the user water temperature 

when the compressors are Off, while this 

can not be obtained if the water tank is 

installed on the hot water inlet water side. 








LZH/LS LOW NOISE VERSION 







LZH 

65 


60 

55 

Water temperature production(°C). 

50 

45 

40 

35 

30 

25 

20 

-20 -15 -10 -5 0 5 10 15 20 25 30 

Ambient temperature (°C). 

LZH 2 PIPES VERSION. 

LZH/SW6 4 PIPES VERSION. 

31 

www.hidros.it

LZH 

LZH 

Versions LZH- LZH/SW6 Code 06 08 10M 10T 14M 

Main switch 


Flow switch 







A1ZZ 

A2 Hydraulic kit (tank and 2 pumps) A2ZZ – – – – – 


A1NT 

A2NT Hydraulic kit (2 pumps only) A2NT – – – – – 

A0NP Hydraulic kit (with tank, without pump) AONP – – – – – 


LS00 


KAVG 


RAEV 


RAES 


RIAO 


MAML 


DSSE 


PCRL 


BRCA 

Coil protection mesh with metallic fi lter FAMM – – – – – 


INSE 


LZH 06÷10T LZH 14÷21 


06/06A1 989 1103 380 95/148 

08/08A1 989 1103 380 104/163 

10M/10MA1 989 1103 380 118/179 

10T/10TA1 989 1103 380 120/181 


14M/14MA1 1323 1203 423 127/207 

14T/14TA1 1323 1203 423 133/212 

21/21A1 1424 1453 473 390/550 

32

LZH 

Versions LZH- LZH/SW6 Code 14T 21 26 36 46 

Main switch 


Flow switch 







A1ZZ 

A2 Hydraulic kit (tank and 2 pumps) A2ZZ – – – – 


A1NT 

A2NT Hydraulic kit (2 pumps only) A2NT – – – – 

A0NP Hydraulic kit (with tank, without pump) AONP – – – – 


LS00 


KAVG 


RAEV 


RAES 


RIAO 


MAML 


DSSE 


PCRL 


BRCA 

Coil protection mesh with metallic fi lter FAMM – – 


INSE 


LZH 

LZH 26÷36 LZH 46 


26/26A1 1406 1870 850 350/510 

36/36A1 1406 1870 850 390/550 

46/46A1 1759 2608 1105 660/810 

33 

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CZT 

High efficiency air to water heat pumps with E.V.I. 

compressors 

CZT 

-15°C 

+63°C 

E.V.I. 

C.O.P.≥4,1 

The high effi ciency CZT heat pump series have been 



have the highest maximum effi ciency in heating mode. 

The units have been designed for internal installation in 

technical vanes and they are supplied of centrifugal ductable 

fans. 

The units have been optimized for heating mode, they are 

able to produce water up to 63°C and they can operate down 

to -15°C ambient temperature. 

The CZT units are available in the 2 pipes version and in the 


Both the versions can produce domestic hot water; the CZT 




version. 




• CZT 2 pipes reversible standard. 

• CZT/SW6 4 pipes unit able to produce hot and cold 


circuits. 

ACCESSORIES 

• 

• 

• 

• 

• 

• 

• 

• 

• 


pumps contacts (user pump, domestic hot water 

pump). 








heater. 

34

CZT 

Model CZT - CZT/SW6 06 08 10M 10T 14T 



COP (EN14511) (1) W/W 3,3 3,5 3,6 3,6 3,6 



COP (EN14511) (2) W/W 2,7 2,9 3,0 2,9 4,2 



COP (EN14511) (3) W/W 2,4 2,6 2,6 2,7 2,7 



EER (EN14511) (4) W/W 2,8 3,3 3,3 3,3 3,3 



EER (EN14511) (5) W/W 2,2 2,8 2,8 3,0 2,7 

Power supply V/Ph/Hz 230/1/50 400/3+N/50 


Peak current A 62,6 80,6 102,6 47,6 62,6 

Fans / Available static pressure n° / Pa 1 / 50 1 / 50 1 / 50 1 / 50 2 / 50 

Compressors n°/tipo 1 Scroll 1 Scroll / E.V.I. 





CZT 

Model CZT - CZT/SW6 21 26 36 46 52 



COP (EN14511) (1) W/W 3,8 3,6 4,0 4,1 4,1 



COP (EN14511) (2) W/W 4,4 4,2 4,1 4,4 4,1 



COP (EN14511) (3) W/W 3,0 2,7 3,1 3,2 3,5 



EER (EN14511) (4) W/W 3,4 3,4 3,6 3,5 3,6 



EER (EN14511) (5) W/W 2,9 2,7 3,0 3,1 3,1 



Peak current A 107,0 102,0 130,5 171,0 126,6 

Fans / Available static pressure n° 2 / 50 2 / 50 2 / 50 2 / 50 2 / 50 

Compressors n°/tipo 1 Scroll / E.V. 2 Scroll / E.V.I. 











35 

www.hidros.it

CZT 

CZT 

FRAME 

All CZT units are made from hot-galvanised 


























COMPRESSORE 














Each scroll compressor used in the CZT 












evaporating pressures, the more the per- 

formance gains with this system compared 

to any other compressor technology. The 

compressors are all supplied with crankcase 

heater and thermal overload protection 

by a klixon embedded in the motor winding. 

They are mounted in a separate chamber in 

order to be separated from the air stream. 

The crankcase heater is always powered 

when the compressor is in stand-by. The 

inspection is possible through the frontal 

panel of the unit that allows the maintenance 

of the compressors even if the unit 

is working. 



























protection. 

FANS 

The fans are made of galvanized steel, 

centrifugal type, double inlet with forward 

curved blades. They are statically and dynamically 

balanced and supplied complete 

of the safety fan guard according to EN 

294. They are mounted on the unit frame 

by interposition of rubber vibration dampers. 

The electric motors are 4 poles (about 

1500 rpm), they are directly driven (06,08, 

10 sizes only) or connected to the fans by 

pulleys and belts (all other sizes). The protection 

class of the motors is IP 54. 


All CZT units are supplied standard with 

microprocessor controls. The microprocessor 


of the water temperature, antifreeze 

protection, compressor timing, compressor 



















ELECTRIC BOX 





panel of the unit. In all CZT units are installed, 


relay (only in triphase versions) which disable 








and fans), compressors fuses, compressor 

contactors, fan contactors, pump contactors 

(if present). The terminal board is supplied 

with voltage free contacts for remote 

ON-OFF , winter/summer change over and 

general alarm. 










36

CZT 





fl ow switch. 


CZT/SW6 UNIT WITH INDEPENDENT 


















priorities. 

VERSIONS 

CZT / A1 HIGH EFFICIENCY HEAT 

PUMP WITH INTEGRATED HYDRAULIC 

KIT 

The CZT heat pumps can be delivered 


includes: 







fl uctuations in the water temperature due to 

the compressors starts and stops. 








CZT/LS LOW NOISE VERSION 







CZT 

CZT 2 PIPES VERSION. 

CZT/SW6 4 PIPES VERSION. 

37 

www.hidros.it

CZT 

CZT 

Versions CZT - CZT/SW6 Code 06 08 10M 10T 14M 14T 

Main switch 


Flow switch 

Pressure control by transducer and modulating damper 






A1ZZ 

A2 Hydraulic kit (tank and 2 pumps) A2ZZ – – – – – – 


A1NT 

A2NT Hydraulic kit (2 pumps only) A2NT – – – – – – 

A0NP Hydraulic kit (with tank, without pump) AONP – – – – – – 


LS00 


KAVG 


RAEV 


RAES 


RIAO 


MAML 


DSSE 


PCRL 


BRCA 

Coil protection mesh with metallic fi lter FAMM – – – – – – 


INSE 



06/06A1 989 1103 650 102/155 

08/08A1 989 1103 650 110/170 

10/10A1 989 1103 650 128/187 

14/14A1 1324 1203 694 135/217 

21/21A1 1424 1453 780 142/222 

38

CZT 

Versions CZT - CZT/SW6 Code 21 26 36 46 52 

Main switch 


Flow switch 

Pressure control by transducer and modulating damper 






A1ZZ 

A2 Hydraulic kit (tank and 2 pumps) A2ZZ – – – 


A1NT 

A2NT Hydraulic kit (2 pumps only) A2NT – – – 

A0NP Hydraulic kit (with tank, without pump) AONP – – – 


LS00 


KAVG 


RAEV 


RAES 


RIAO 


MAML 


DSSE 


PCRL 


BRCA 

Coil protection mesh with metallic fi lter FAMM – 


INSE 


CZT 


26/26A1 1270 1870 850 329/436 

36/36A1 1566 2608 1105 343/491 

46/46A1 1566 2608 1105 356/516 

52/52A1 1566 2608 1105 375/530 

39 

www.hidros.it

WZT 

High efficiency air to water heat pumps with 

E.V.I. compressors in two sections 

WZT 

-15°C 

+63°C 

E.V.I. 

C.O.P.≥4,1 

The high effi ciency WZT heat pump series have been 



have the highest maximum effi ciency in heating mode. 


able to produce water up to 63°C and they can operate down 

to -15°C ambient temperature. 

These units have been designed to be installed in applications 

where the noise has to be as low as possible. The units, so, 

are supplied in two sections, connected thanks to refrigerant 

lines. The compressor is installed in the internal section. 

The WZT units are available in the 2 pipes version and in the 


Both the versions can produce domestic hot water; the WZT 




version. 




• WZT 2 pipes reversible standard. 

• WZT/SW6 4 pipes unit able to produce hot and cold 


circuits. 

ACCESSORIES 

• 

• 

• 

• 

• 

• 

• 

• 



pump). 






Super low noise external unit. 

40

WZT 

Model WZT - WZT/SW6 06 08 10M 10T 14M 14T 21 

Heating capacity (EN14511) (1) kW 6,6 8,7 9,6 9,6 13,9 13,9 19,6 

Total input power (EN14511) (1) kW 1,6 2,1 2,3 2,3 3,4 3,2 4,5 

COP (EN14511) (1) W/W 4,1 4,1 4,2 4,2 4,1 4,3 4,4 



COP (EN14511) (2) W/W 3,3 3,3 3,5 3,5 3,5 3,7 3,6 



COP (EN14511) (3) W/W 3,0 3,1 3,2 3,4 3,2 3,3 3,5 

Cooling capacity (EN14511) (4) kW 6,9 9,6 11,3 11,3 15,4 15,5 21,4 


EER (EN14511) (4) W/W 3,3 3,8 3,8 3,8 3,8 3,9 3,8 



EER (EN14511) (5) W/W 2,7 3,3 3,3 3,6 3,2 3,3 3,3 

Power supply V/Ph/Hz 230/1/50 400/3+N/50 230/1/50 400/3+N/50 

Max input current A 17,0 21,0 25,5 8,0 33,0 12,0 19,5 

Peak current A 60,0 78,0 100,0 45,0 162,0 60,0 106,0 

Compressors n°/tipo 1/Scroll HP 1/Scroll con EVI 

Internal unit sound power level (6) dB (A) 51 52 52 52 54 54 60 

Internal unit sound pressure level (7) dB (A) 43 44 44 44 46 46 52 

Std external unit sound power level (6) dB (A) 62 62 62 62 69 69 70 

Std external unit sound pressure level (8) dB (A) 34 34 34 34 41 41 42 

WZT 

Model WZT - WZT/SW6 26 36 46 52 72 82 92 



COP (EN14511) (1) W/W 4,1 4,5 4,5 4,5 4,1 4,1 4,1 



COP (EN14511) (2) W/W 3,4 3,6 3,7 3,6 3,4 3,4 3,5 



COP (EN14511) (3) W/W 3,1 3,4 3,5 3,5 3,1 3,2 3,1 



EER (EN14511) (4) W/W 3,8 3,9 3,7 3,8 3,6 3,5 3,5 



EER (EN14511) (5) W/W 3,0 3,2 3,1 3,2 2,9 2,9 2,9 


Max input current A 22,0 26,0 31,1 39,7 50,0 58,0 71,2 

Peak current A 101,0 129,0 170,0 121,0 155,0 199,0 237,0 

Compressors n°/tipo 1/Scroll con EVI 2/Scroll con EVI 

Internal unit sound power level (6) dB (A) 60 60 60 61 62 63 63 

Internal unit sound pressure level (7) dB (A) 52 52 52 53 54 55 55 

Std external unit sound power level (6) dB (A) 70 70 70 72 Contact the company 

Std external unit sound pressure level (8) dB (A) 42 42 42 44 Contact the company 





(7) Sound pressure level at 1 mt from the unit in free fi eld conditions direction factor Q=2, according (8) Sound pressure level at 10 mt from the unit in free fi eld conditions direction factor Q=2, 


according to ISO 3746 (LS version) 

41 

www.hidros.it

WZT 

WZT 

FRAME 

All WZT units are made from hot-galvanised 


























COMPRESSOR 











consists of injecting refrigerant vapour 

in the middle of the compression process, 

to boost capacities and effi ciencies signifi - 

cantly. Each scroll compressor used in the 

WZT units is basically similar to a two-stage 

compressor but with built-in interstage cooling. 

The highest stage consists of extracting 

a portion of the condenser liquid and 

expanding it through an expansion valve 

into a heat exchanger acting as a sub cooler. 

The superheated vapour is then injected 

into an intermediate part in the scroll compressor. 


the evaporator capacity. The bigger is 

the pressure ratio between condensing and 

evaporating pressures, the more the per- 

formance gains with this system compared 

to any other compressor technology. The 

compressors are all supplied with crankcase 


by a klixon embedded in the motor winding. 

They are mounted in a separate chamber in 

order to be separated from the air stream. 

The crankcase heater is always powered 

when the compressor is in stand-by. The 

inspection is possible through the frontal 

panel of the unit that allows the maintenance 

of the compressors even if the unit 

is working. 

REMOTE SOURCE EXCHANGER 














blades directly connected to the electric 

motor with internal thermic protection and 

supplied of accident prevention measures. 

The remote condenser is also supplied of a 

condenser control with fan speed control. 

This device controls the condensing pressure 

of the refrigerant circuit at different 

ambient conditions, in order to keep the 

correct condensing pressure. The protection 

class of the motors is IP 54 














protection. 


All WZT units are supplied standard with 























ELECTRIC BOX 





panel of the unit. In all WZT units is installed, 


relay (only in triphase versions) which disables 








and fans), compressors fuses, compressor 

contactors, fan contactors, pump contactors 

(if present). The terminal board is supplied 

with voltage free contacts for remote 

ON-OFF, winter/summer change over and 

general alarm. 










42

WZT 





fl ow switch. 


WZT/SW6 UNIT WITH INDEPENDENT 


















priorities. 

VERSIONS 

WZT / A1 HIGH EFFICIENCY HEAT 

PUMP WITH INTEGRATED HYDRAULIC 

KIT 

The WZT heat pumps can be delivered 


includes: 







fl uctuations in the water temperature due 

to the compressors starts and stops. 








WZT/LS LOW NOISE VERSION 







WZT 

Connections diagrams WZT WZT/SW6 

WZT 2 PIPES VERSION. 

WZT/SW6 4 PIPES VERSION. 

43 

www.hidros.it

WZT 

WZT 

Version WZT - WZT/SW6 Code 06 08 10M 10T 14M 14T 

Main switch 


Flow switch 







LS00 


KAVG 


RAEV 


MAML 

Electronic soft starter 

DSSE 


PCRL 

Serial interface card RS485 

INSE 

Standard, 

Optional, – Not Available. 

WZT A (mm) B (mm) C (mm) Kg WZT/SW6 A (mm) B (mm) C (mm) Kg 

06 940 700 570 80 06 940 700 570 83 

08 940 700 570 83 08 940 700 570 86 

10M 940 700 570 95 10M 940 700 570 98 

10T 940 700 570 95 10T 940 700 570 98 

14M 940 700 570 112 14M 1280 1003 633 115 

14T 940 700 570 112 14T 1280 1003 633 115 

21 940 700 570 125 21 1280 1003 633 128 

26 940 700 570 138 26 1280 1003 633 142 

36 1280 1003 633 144 36 1280 1003 633 148 

46 1280 1003 633 153 46 1280 1003 633 157 

A 

B 

Model 06-08 

C 

A 

B 

C 


06 1230 600 1500 79 

08 1230 600 1500 79 

10M 1230 600 1500 79 

10T 1230 600 1500 79 

14M 1370 800 1910 145 

14T 1370 800 1910 145 

21 2630 600 1230 150 

26 2630 600 1230 150 

36 2630 600 1230 183 

46 3230 800 1370 279 

44

WZT 

Version WZT - WZT/SW6 Code 21 26 36 46 52 72 82 92 

Main switch 


Flow switch 

Evap/cond pressure control by transducer and fan speed control 






LS00 


KAVG 


RAEV 


MAML 


DSSE 


PCRL 


INSE 

WZT 

Standard, 


B 

C 

A 


52 1855 800 800 455 

72 1855 800 800 475 

82 1855 800 800 485 

92 1855 1478 800 575 


52 3230 800 1370 302 

72 

82 

Contact The Company 

92 

45 

www.hidros.it

WZH 

Ground source heat pumps 

WZH 

+60°C 

C.O.P.≥5,1 

The WZH heat pumps are particularly suitable for the use in 

applications with well water or with ground source probes. 

These units have been designed for radiant fl oor heating systems 

or for those applications in which the maximum heating 

effi ciency is required. 

The units have been designed to have an effi cient performance 

in heating and they can work with water temperature 

up to 60°C. 

WZH are available in more versions; 2 pipes confi guration 

user side and 4 pipes confi guration user side. All the WZH 

versions are able to produce domestic hot water; The 2 pipes 

version through the activation of an external 3 way valve, 

the 4 pipes version through a hydraulic circuit for the domestic 

hot water which allows the production independently 

from the unit mode. 

All the WZH units are also available in Free Cooling (FC) 

versions which allow to have the maximum energetic saving 

in summer mode, using the cold energy coming from the 

ground source probes or the well water, source side. 

The available versions and the wide range of accessories 

allow to choose the right model and solution for each application. 


• WZH Standard, heating only. 

• WZH/SW5 Heating only + domestic hot water circuit. 

• WZH/RV Reversible heating/cooling. 

• WZH/RV/SW6 Reversible version heating/cooling 

with independent DHW circuit. 

ACCESSORIES 

• Low noise version LS. 

• FC free cooling version (available in all versions 

WZH/FC , WZH/FC/SW5, WZH/FC/RV, WZH/FC/RV/ 

SW6). 

• Pumps contacts (source, user, domestic hot water 

pump). 

• Electronic soft starter. 

• Rubber vibration dampers. 

• Spring vibration dampers. 

• Refrigerant pressure gauges. 

• Remote control panel. 

• Serial interface card RS 485. 

• 2 way modulating valve to reduce source water consumption 

(4-20 mA; 0-10 V). 

46

WZH 

Model WZH 05 07 09 11 13 15 20 30 

Heating capacity (EN14511) (1) kW 7,4 10,0 12,5 14,4 17,8 20,9 27,0 38,0 

Input power (EN14511) (1) kW 1,5 1,9 2,4 2,7 3,2 3,8 5,2 7,1 

COP (EN14511) (1) w/w 4,9 5,3 5,2 5,3 5,6 5,5 5,2 5,4 

Source water fl ow (1) m 3 /h 1,3 1,8 2,2 2,5 3,2 3,7 4,8 6,8 

Heating capacity (EN14511) (2) kW 5,5 7,2 9,2 10,8 12,9 16,0 20,4 28,1 


COP (EN14511) (2) w/w 3,9 4,2 4,2 4,2 4,4 4,4 4,3 4,5 

Cooling capacity (EN14511) (3) kW 8,2 11,1 13,9 15,9 19,8 22,8 29,0 41,9 


EER (EN14511) (3) w/w 4,8 5,6 5,6 5,7 5,7 5,6 4,9 5,3 

Cooling capacity (EN14511) (4) kW 5,6 8,2 10,1 11,1 14,4 16,4 20,6 29,3 


EER (EN14511) (4) w/w 3,7 4,6 4,4 4,3 4,5 4,4 4,0 4,4 

Power supply 230/1/50 400/3 + N/50 

Nominal input current A 9,4 12,3 15,5 18,5 9,7 11,3 15,4 19,7 

Peak current A 42,0 68,0 75,0 82,0 68,0 77,0 102,0 129,0 

Maximum input current A 10,0 13,3 16,5 19,6 12,0 14,1 18,2 21,4 

Compressors / Circuits n° 1/1 1/1 

Evaporator / Number Plates / 1 

Condenser / Number Plates / 1 

Sound power (5) dB(A) 51 52 52 53 54 54 60 60 

Sound pressure (6) dB(A) 43 44 44 45 46 46 52 52 

WZH 

(1) 

Heating: condenser water temperature in/out 30/35°C; evaporator water temperature in/out 10/7°C..unit without pressostatic valve. 

(2) 

Heating: condenser water temperature in/out 30/35°C; evaporator water temperature in/out 0/-3°C. unit without pressostatic valve. 

(3) 

Cooling: data are refferred to unit with pressostatic valve. : evaporator water in/out 23/18°C, condenser water temperature in/out 30/35°C. 

(4) 

Cooling: data are refferred to unit with pressostatic valve: evaporator water in/out 12/7°C, condenser water temperature in/out 30/35°C. 

(5) 

Sound power according to ISO 3746. 

(6) 

Sound pressure level measured at 10 mt from the unit in free fi eld conditions direction factor Q=2 according to ISO 3746. 

47 

www.hidros.it

WZH 

WZH 

FRAME 

All WZH units are made from hot-galvanised 


powder enamel at 180°C to ensure 

the best resistance against the atmospheric 


removable panels. All screws and rivets are 

in stainless steel. The colour of the units is 

RAL 7035. 





and according to welding procedures. 

Each refrigerant circuit is totally independent 

from the other. Any incorrect operation 

of one circuit does not infl uence the other 

circuit. The refrigerant circuit includes: 

sight glass, fi lter drier, thermal expansion 

valve with external equalizer, Schrader 

valves form maintenance and control, 

pressure safety device (according to PED 

regulation). 

COMPRESSORS 

The WZH units are supplied with scroll type 

compressors, optimized for heating applications 

with a special scroll design which 

allows extreme high effi ciencies especially 

when the heat source temperature is low. 

Compressors are supplied with crankcase 

heater and thermal overload protection by 

a klixon embedded in the motor winding. In 

all units the crankcase heaters are always 

powered when the compressors are in 

stand-by. The inspection is possible through 

the frontal panel of the unit that allows 

the maintenance of the compressors even 

if the unit is working. 

SOURCE SIDE HEAT EXCHANGERS 

The source side heat exchangers are made 

of AISI 316 stainless steel braze-welded 

plates type. They are single water side circuit. 

The use of this kind of heat exchangers 



traditional shell-in-tube ones and increases 

the effi ciency of the refrigerant cycle in partial 

loads. The source heat exchangers are 


and are provided with a temperature 

sensor as antifreeze protection. 

USER SIDE HEAT EXCHANGERS 

The user side heat exchangers are made of 

AISI 316 stainless steel braze-welded plates 

type. They are single water side circuit. 

All units are supplied with sub-cooler to 

enhance the performance of the refrigerant 

cycle. The user heat exchangers are factory 

insulated with fl exible close cell material. 


All WZH units are supplied standard with 





automatic starting sequence, alarm reset, 

potential free contact for remote general 

alarm, alarms and operation leds. Upon 

request any microprocessor can be connected 

to a BMS system for the remote 

control and management. The technical 

department is available to study, together 

with the customer, different solutions using 

MODBUS protocols. 

ELECTRIC BOX 

The electric switch board is made according 

to electromagnetic compatibility norms 

CEE 73/23 and 89/336. The accessibility 

to the board is possible after removing the 

front panel of the unit and the OFF positioning 

of the main switch. In all WZH units 

are installed, standard, the compressors 

sequence relay which disables the operation 

of the compressor in case the power 

supply phase sequence is not the correct 

one (scroll compressors in fact, can be 

damaged if they rotate reverse wise). The 

following components are also standard 

installed: main switch, magnetic-thermal 

switches as a protection of compressors 

and pumps (where present), control circuit 


pump contactors. The terminal board 

is supplied with voltage free contacts for 

remote ON-OFF, Summer / Winter change 

over and general alarm. 



control and protection devices: Return and 

supply user heat exchanger sensors, return 

and supply source heat exchanger sensors, 

high pressure switch with manual reset, low 



overload protection, pump thermal overload 

protection (when present), source heat 

exchanger fl ow switch. 

OTHER VERSION 

WZH/SW5 UNIT WITH DOMESTIC HOT 

WATER PRODUCTION 

This version is suitable to produce domestic 

hot water: the unit is supplied with an ON/ 

OFF 3 way valve to deviate the water fl ow 

to a circuit for hot water production;These 

units are not available in the reversible 

version (RV) and can not produce cold 

water. 

WZH/RV REVERSIBLE VERSION HEATING/ 

COOLING 

This version is even suitable for cooling during 

summer operation by using a 4 way reverse 

cycle valve in the refrigerant circuit, second 

thermostatic valve, liquid receiver. 

WZH/RV/SW6 REVERSIBLE VERSION 

HEATING/COOLING WITH INDEPEN- 

DENT DHW CIRCUIT 

This version is supplied complete with 4 

pipes on the user side and is able to produce, 

at the same time, hot and cold water 

on 2 independent hydraulic circuits. On this 

version, the domestic hot water production 


the unit. This unit is supplied, standard, with 

a reverse cycle valve to allow even the production 

of cold water in summer mode. 

WZH/FC; WZH/FC/RV; WZH/FC/SW5 

WZH/FC/RV/SW6 FREE COOLING VER- 

SIONS 

These versions in addition to the standard 

characteristics are suitable for cold water 

production during summer operation 

using the cold water fl ow coming from 

the source ground probes. All free cooling 

versions are supplied with an intermediate 

heat exchanger and a 3 way valve which 

manages the water fl ow to the user circuit 

depending on the required user cold water 

temperature. During free cooling mode 

the compressors may be off or work as 

integration. 

48

WZH 

WZH 

WZH/RV. 

This version is even suitable for cooling 

during summer operation by using a 4 

way reverse cycle valve in the refrigerant 

circuit. 

WZH/RV/SW6. 

This version is supplied complete with 4 

pipes on the user side and is able to produce, 

at the same time, hot and cold water 

on 2 independent hydraulic circuits. On this 

version, the domestic hot water production 


the unit. 

49 

www.hidros.it

WZH 

WZH 

WZH/FC/RV. 

These versions in addition to the standard characteristics are suitable for cold water production during summer operation using the cold 

water fl ow coming from the source ground probes. All free cooling versions are supplied with an intermediate heat exchanger and a 3 way 

valve which manages the water fl ow to the user circuit depending on the required user cold water temperature. During free cooling mode 

the compressors may be off or work as integration. 

WZH/FC/RV/SW6. 

50

WZH 

Model WZH Codice 05 07 09 11 13 15 20 30 

Main switch 

Microprocessor control 

Low noise version LS (standard) 

Contacts for pumps ( source, user, domestic hot water pump) 

2 way modulating to control source water consumption (4-20 mA; 0-10 v) VM2D 



Spring vibration dampers 




DSSE 

KAVG 

KAVM 

MAML 

PCRL 

INSE 

WZH 

Standard, 

Optional, – Not available. 

FRAME 1 FRAME 2 

WZH WZH/SW5 WZH/RV/SW6 WZH/RV WZH/FC WZH/FC/RV WZH/FC/SW5 WZH/FC/RV/SW6 A (mm) B (mm) C (mm) Kg F 

05 05 05 05 - - - - 940 700 570 83 1 

07 07 07 07 - - - - 940 700 570 86 1 

09 09 09 09 - - - - 940 700 570 96 1 

11 11 11 11 - - - - 940 700 570 101 1 

13 13 - 13 - - - - 940 700 570 110 1 

15 15 - 15 - - - - 940 700 570 118 1 

20 20 - 20 - - - - 940 700 570 130 1 

30 30 - 30 - - - - 940 700 570 144 1 

- - - - 05 05 05 05 1280 1003 633 100 2 

- - - - 07 07 07 07 1280 1003 633 107 2 

- - - - 09 09 09 09 1280 1003 633 115 2 

- - - - 11 11 11 11 1280 1003 633 118 2 

- - 13 - 13 13 13 13 1280 1003 633 130 2 

- - 15 - 15 15 15 15 1280 1003 633 138 2 

- - 20 - 20 20 20 20 1280 1003 633 147 2 

- - 30 - 30 30 30 30 1280 1003 633 162 2 

51 

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Ground source heat pumps 


+60°C 

C.O.P.≥5,1 

These versions in addition to the standard characteristics are 

suitable for cold water production during summer operation 

using the cold water fl ow coming from the ground probes 

The high effi ciency WDH heat pump series have been especially 

designed for application with radiant fl oor heating systems 

or in those applications where it is necessary to have 

the highest maximum effi ciency in heating mode. 


able to produce water up to 60°C. 

The WDH units are available in the 2 pipes version and in the 


Both the versions can produce domestic hot water; the WDH 




version. 

These units are also available in free cooling version (FC) 

which allows the get the maximum energy saving in summer 

mode, using the cold energy coming from the ground 

probes. 

All the available versions and the wide range of accessories 

permit to choose the right model for any necessity. 


• WDH standard, heating only. 

• WDH/SW5 heating only + domestic hot water circuit. 

• WDH/RV reversible heating/cooling. 

• WDH/RV/SW6 reversible version heating/cooling 

with independent DHW circuit. 

ACCESSORIES 

• LS Low noise version. 

• FC free cooling version (available in all versions 

WDH/FC, WDH/FC/SW5, WDH/FC/RV, WDH/FC/RV/ 

SW6). 

• Pumps contacts (source, user, domestic hot water 

pump). 

• Electronic soft starter. 

• Rubber vibration dampers. 

• Spring vibration dampers. 

• Refrigerant pressure gauges. 

• Remote control panel. 

• Serial interface card RS 485. 

• 2 way modulating valve to reduce source water consumption 

(4-20 mA; 0-10 V). 

52


Model WDH WDH/SW6 039 045 050 060 070 080 090 110 120 130 

Heating capacity (EN14511) (1) kW 48,2 58,7 67,9 75,8 83,7 101,7 118,4 135,2 152,3 169,5 

Total input power (EN14511) (1) kW 9,4 11,4 12,9 14,6 16,2 19,4 22,5 25,7 28,9 32,1 

COP (EN14511) (1) W/W 5,1 5,1 5,3 5,2 5,2 5,2 5,3 5,3 5,3 5,3 

User water fl ow (EN14511) (1) m 3 /h 11,2 13,6 15,.8 17,6 19,4 23,6 27,5 31,4 35,4 39,4 



COP (EN14511) (2) W/W 3,9 3,9 4,0 4,0 4,0 4,1 4,1 4,2 4,2 4,1 

Cooling capacity (EN14511) (3) kW 56,2 70,2 82,8 86,9 101,8 123,1 143,4 157,0 185,6 207,3 


EER (EN14511) (3) W/W 5,7 5,8 6,0 5,5 5,7 5,8 5,9 5,6 5,9 5,8 



EER (EN14511) (4) W/W 4,2 4,2 4,3 4,2 4,2 4,3 4,3 4,3 4,3 4,3 

Free Cooling capacity (5) kW 24,0 28,0 33,0 37,0 41,0 50,0 58,0 66,0 74,0 83,0 

Power supply 

400V / 3Ph / 50 Hz 

Nominal input current A 27,0 30,6 32,0 34,7 37,4 47,2 53,9 58,4 67,3 76,4 

Peak current A 116,0 143,0 149,0 189,0 194,0 230,0 257,0 266,0 313,0 324,0 

Maximum input current A 34,0 40,0 44,0 49,0 54,0 64,0 73,0 82,0 93,0 104,0 

Compressors type / n° / Circuits Scroll / 2 / 1 

Capacity steps n° 2 2 2 2 2 2 2 2 2 2 

Water pump kW 1,1 1,1 1,1 1,1 1,1 1,5 1,5 2,2 2,2 2,2 

Pump available static pressure kPa 155 130 100 80 60 105 65 80 60 50 

Sound power (6) dB(A) 80 80 81 82 82 83 83 84 84 85 

Sound pressure (7) dB(A) 52 52 53 54 54 55 55 56 56 57 


(1) 

Heating: user water temperature 30/35°C, source water temperature 10/7°C. 

(2) 

Heating: user water temperature 30/35°C, source water temperature 0/-3°C con 10% glycol. 

(3) 

Cooling: user water temperature 23/18°C, source water temperature 30/35°C. 

(4) 

Cooling: user water temperature 12/7°C, source water temperature 30/35°C. 

(5) 

Cooling: user water temperature 10°C, source water temperature 20°C. 

(6) 

Sound power level according to ISO 3746. 

(7) 

Sound pressure level at 10 mt from the unit in free fi eld conditions direction factor Q=2, according 


53 

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Model WDH WDH/SW6 152 162 144 164 190 210 240 260 300 320 



COP (EN14511) (1) W/W 5,4 5,4 5,2 5,3 5,3 5,3 5,3 5,3 5,4 5,5 

User water fl ow (EN14511) (1) m 3 /h 44,2 48,9 43,0 47,3 55,0 62,8 70,8 78,9 88,3 97,8 



COP (EN14511) (2) W/W 4,2 4,2 4,0 5,5 4,0 4,0 4,0 4,0 4,1 4,1 



EER (EN14511) (3) W/W 5,7 6,0 5,4 5,6 6,0 6,0 6,0 6,0 6,1 6,3 


Total input power (EN14511) (4) kW 36,9 40,1 37,3 40,6 47,3 54 60,6 67,3 73,8 80,3 

EER (EN14511) (4) W/W 4,4 4,5 4,2 4,3 4,3 4,3 4,3 4,3 4,4 4,5 

Free Cooling capacity (5) kW 92,0 102,0 90,0 99,0 115,0 162,0 148,0 165,0 184,0 204,0 

Power supply 

400V / 3Ph / 50 Hz 

Nominal input current A 83,9 91,4 86,0 94,4 105,0 122,4 134,6 152,8 167,8 182,8 

Peak current A 362,0 372,5 279,8 294,0 330,0 348,0 406,0 428,0 476,5 497,5 

Maximum input current A 114,5 125,0 109,6 128,0 146,0 164,0 186,0 208,0 229,0 250,0 

Compressors type / n° / Circuits Scroll / 2 / 1 Scroll / 4 / 2 

Capacity steps n° 2 2 4 4 4 4 4 4 4 4 

Water pump kW 3,0 3,0 3,0 3,0 3,0 4,0 4,0 4,0 5,5 5,5 

Pump available static pressure kPa 140 117 143 120 80 150 120 90 140 120 

Sound power (6) dB(A) 85 85 85 85 86 88 88 88 90 90 

Sound pressure (7) dB(A) 57 57 57 57 58 60 60 60 62 62 

(1) (2) 

Heating: user water temperature 30/35°C, source water temperature 10/7°C. Heating: user water temperature 30/35°C, source water temperature 0/-3°C con 10% glycol. 

(3) (4) 

Cooling: user water temperature 23/18°C, source water temperature 30/35°C. Cooling: user water temperature 12/7°C, source water temperature 30/35°C. 

(5) (6) 

Cooling: user water temperature 10°C, source water temperature 20°C. Sound power level according to ISO 3746. 

(7) 

Sound pressure level at 10 mt from the unit in free fi eld conditions direction factor Q=2, according 


54


FRAME 

All WDH units are made from hot-galvanised 


powder enamel at 180°C to ensure 

the best resistance against the atmospheric 










welding procedures. Each refrigerant 

circuit is independent from the other. The 

refrigerant circuit includes: 


valves with external equalizer, Schrader 

valves for maintenance and control, pressure 

safety device (according to PED regulation). 

USER EXCHANGER 

The user side heat exchangers are made of 

AISI 316 stainless steel braze-welded plates 

type. From size 039 to size 162 they are 

single water side circuit, from the size 144 

they are double circuit “cross fl ow” type. All 

units are supplied with sub-cooler to enhance 

the performance of the refrigerant cycle. 

The user heat exchangers are factory insulated 

with fl exible close cell material. 


All WDH units are supplied standard with 






one compressor is present), alarm reset, 

alarms and functioning leds management. 

The technical department is available to 

study, together with the customer, different 

solutions using MODBUS. 


WDH/SW5 ONLY HEATING - UNIT WITH 

DOMESTIC HOT WATER 

This version is suitable to produce domestic 

hot water: the unit is supplied with an ON/ 

OFF 3 way valve to deviate the water fl ow 

in a water accumulator; the activation of the 

3 way valve is done automatically by the 


hot water temperature in the accumulator 

is lower than the required set point. These 

units are not available in the reversible 

version (RV) and they can not produce 

cooled water. 

WDH/RV REVERSIBLE VERSION HOT/COLD 

This version is suitable for cooling during 


cycle valve, second thermostatic valve, 

liquid receiver. 


COMPRESSORS 

The WDH units are supplied with scroll type 

compressors, optimized for heating applications 

with a special scroll design which 

allows extreme high effi ciencies especially 

when the heat source temperature is low. 

Compressors are supplied with crankcase 

heater and thermal overload protection by 

a klixon embedded in the motor winding. 

The compressors used are all in tandem 

execution. This solution allows much higher 

effi ciencies in partial loads compared to the 

units with independent refrigerant circuits. 

In all units the crankcase heaters are always 

powered when the compressors are 

in stand-by. 

SOURCE SIDE HEAT EXCHANGERS 

The source side heat exchangers are made 


plates type. From size 039 to size 162 they 

are single water side circuit, from the size 

144 they are double circuit “cross fl ow” 




traditional shell-in-tube ones and increases 

the effi ciency of the refrigerant cycle in partial 

loads. The source heat exchangers are 


and are provided with a temperature 

sensor as antifreeze protection. 

ELECTRIC BOX 




board is possible after removing the frontal 

panel of the unit. In all WDH units is installed, 


relay which disables the operation of the 

compressor in case the power supply phase 

sequence is not the correct one (scroll 

compressors in fact, can be damaged if 

they rotate reverse wise). The following 

components are also standard installed: 

main switch, magnetic-thermal switches 

(as a protection of pumps and fans), compressors 

fuses, compressor contactors, fan 

contactors, pump contactors (if present). 


free contacts for remote ON-OFF and general 

alarm. 



control and protection devices: Return and 

supply user heat exchanger sensors, return 

and supply source heat exchanger sensors, 

high pressure switch with manual reset, low 



overload protection, pump thermal overload 

protection (when present), source heat 

exchanger fl ow switch. 

WDH/RV/SW6 REVERSIBLE 

HOT/COLD – INDEPENDENT DOMESTIC 

HOT WATER CIRCUIT 

This unit is supplies with 4 pipes on the user 

side and is able to produce hot and cold 

water at the same time on two independent 

hydraulic dircuits. The unit is supplied with 

an additional heat exchanger used as 


is independend from the operation mode 

of the unit. The activation of the additional 

heat exchanger is done automatically 

by the microprocessor control when the 

domestic hot water temperature measured 

by the sensor is lower than the required set 

point. This unit is supplied, standard, with 

a reverse cycle valve to allow even the 

production of cold water in summer mode. 

55 

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WDH/FC; WDH/FC/RV; WDH/FC/SW5; 

WDH/FC/RV/SW6 

FREE COOLING VERSIONS 

These versions in addition to the standard 

characteristics are suitable for cold water 

production during summer operation using 

the cold water fl ow coming from the ground 

probes. 

During free cooling mode the compressors 

are not working; the system is supplied 

with an intermediate heat exchanger and a 

modulating 3 way valve which manages the 

water fl ow to the user circuit depending on 

the required cold water temperatures. 

VERSIONS 

WDH/A1NT UNIT WITH WATER PUMP 

This version is supplied with a single centrifugal 

type water pump with a high available 

pressure. The pump is connected, 

standard, to the user heat exchanger but, 

upon request, can also be connected to the 

source heat exchanger 

WDH/LS LOW NOISE VERSION 

The low noise versions LS include the 

complete acoustic insulation of the unit 

(compressor + heat exchangers vanes with 

insulating material having high density media 

with the interposition of heavy bitume 

layer. 

WDH/RV 2 PIPES VERSION. 

This version is suitable for cooling during 


cycle valve in the refrigerant circuit. 

56



WDH/FC/RV 2 PIPES VERSION. 

These versions in addition to the standard characteristics are suitable for cold water production during summer operation using the cold 

water fl ow coming from the ground probes. During free cooling mode the compressors are not working; the system is supplied with an 

intermediate heat exchanger and a modulating 3 way valve which manage the water fl ow to the user circuit depending on the required 

cold water temperatures. 

WDH/FC/RV/SW6 2 PIPES VERSION. 

57 

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WDH/RV/SW6 4 PIPES VERSION. 

This unit is supplies with 4 pipes on the user 

side and is able to produce hot and cold 

water at the same time on two independent 

hydraulic dircuits. The unit is supplied with 

an additional heat exchanger used as 



the unit. 

Model WDH Codice 039-045 050-060 070-080 090-110 120-130 

Main switch 




LS low noise version 

Partial heat recovery 20% 

(A1NT) version - one pump without water tank 





Liquid line solenoid valve 



LS00 

RP00 

A1NT 

DSSE 

KAVG 

KAVM 

MAML 

VSLI 

PCRL 

INSE 

2 way modulating to control source water consumption VM2D 

Standard, 


58


Model WDH Codice 152-162 144-164 190-210 240-260 300-320 

Main switch 





Partial heat recovery 20% 

(A1NT) version - one pump without water tank 








LS00 

RP00 

A1NT 

DSSE 

KAVG 

KAVM 

MAML 

VSLI 

PCRL 

INSE 



Standard, 



039 1855 800 800 430 

045 1855 800 800 440 

050 1855 800 800 460 

060 1855 800 800 470 

070 1855 800 800 480 

080 1855 800 800 490 

090 1855 1478 800 580 

110 1855 1478 800 600 

120 1855 1478 800 630 

130 1855 1478 800 650 


152 1855 1478 800 730 

162 1855 1478 800 760 

144 1855 2480 800 1020 

164 1855 2480 800 1090 

190 1855 2480 800 1170 

210 1855 2480 800 1210 

240 1855 2480 800 1270 

260 1855 2480 800 1320 

300 1855 2480 800 1390 

320 1855 2480 800 1430 

59 

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LWZ 

High efficiency air to water HYBRID heat 

pumps with E.V.I compressor 

LWZ 

-15°C 

+63°C 

E.V.I. 

C.O.P.≥4,1 

The high effi ciency LWZ hybrid heat pump series have been 



have the highest maximum effi ciency in heating mode. The 

units have been optimized for heating mode, they are able 

to produce water up to 63°C . The LWZ units are available 

in the 2 pipes version and in the SW6 version, with 4 pipes. 

Both the versions can produce domestic hot water; the LWZ 




version. All models are supplied standard with reverse cycle 

valve for cold water production.The characteristic of LWZ 

units is to have TWO heat exchanger on source side (one air 

fi nned coil and one water plates heat exchanger) that allow 

the unit to work in every ambient condition, running the two 

heat exchangers to reach the maximum effi ciency. The LWZ 

heat pump always work with the air source heat exchanger 

actived and with the external air temperature under 0°C. In 

any case the water source heat exchanger is activated when 

the microprocessor control thinks it necessary. This because 

it integrates the thermal capacity in severe ambient conditions 

and grant a better ecciciency which would be impossible 

with the use of the only air source. 


• LWZ 2 pipes reversible standard. 

• LWZ/SW6 4 pipes unit able to produce hot and cold 


circuits. 

ACCESSORIES 

• 

• 

• 

• 

• 

• 

• 

• 

• 



pump). 








heater. 

60

LWZ 

26 36 52 72 82 92 



COP (EN14511) (1) W/W 4,1 4,5 4,5 4,1 4,1 4,1 

Integrative source water fl ow * (1) l/h 1800 2700 3650 5350 6250 7500 

Heating capacity (2) kW 24,2 34,5 48,4 68,9 83,6 98,9 

Total input power (2) kW 6,3 8,3 13,2 17,1 20,5 24,6 

COP (2) W/W 3,8 4,2 3,7 4,0 4,1 4,0 



COP (3) W/W 3,3 3,5 3,2 3,4 3,6 3,5 



COP (4) W/W 3,2 3,4 3,0 3,3 3,4 3,3 



COP (5) W/W 3,2 3,4 3,1 3,3 3,8 3,4 


Total input power (6) kW 8,3 10,8 17,1 22,1 26,8 31 

COP (6) W/W 3,0 3,1 2,9 3,1 3,2 3,2 



COP (7) W/W 2,7 2,8 2,6 2,8 2,9 2,9 



COP (8) W/W 2,5 2,6 2,5 2,6 2,6 2,7 

Cooling capacity (9) kW 30,9 42,2 57,8 84,4 93,2 117,0 


EER (EN14511) (9) W/W 3,8 3,9 3,8 3,6 3,5 3,5 



EER (EN14511) (10) W/W 3,0 3,2 3,2 2,9 2,9 2,9 


Nominal input current A 22,0 26,0 39,7 50,0 58,0 71,2 

Peak current A 101,0 129,0 121,0 155,0 199,0 237,0 

Compressors type / n° / Circuits Scroll con E.V.I / 2 / 1 

Sound Power (11) dB(A) 79 79 82 82 82 83 

Sound Pressure (12) dB(A) 51 51 54 54 54 53 

LWZ 

* Nominal water fl ow used by the unit at ambient temperature below approx. 0°C. 

(1) 

Heating: Ambient air temperature 7°C DB, 6°C WB, User water temperature 30/35°C. 

(2) 


(3) 

Heating: Ambient air temperature -7°C DB, -8°C WB, User water temperature 30/35°C. 

(4) 


(5) 


(6) 


(7) 


(8) 


(9) 

Cooling: User water temperature 23/18°C, Source water temperature 30/35°C. 

(10) 

Cooling: User water temperature 12/7°C, Source water temperature 30/35°C. 

(11) 

Sound power level according to ISO 3746 (LS version). 

(12) 

Sound pressure level at 10 mt from the unit in free fi eld conditions direction factor Q=2 according to ISO 3746 (LS version). 

61 

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LWZ 

LWZ 

FRAME 

All LWZ units are made from hot-galvanised 

















for heating mode) with external equalizer, 4 

way reverse cycle valve, one way valves, 

liquid receiver, Schrader valves for maintenance 

and control, pressure safety device 

(according to PED regulation). Units are 

also supplied with an AISI316 stainless steel 

heat exchanger used as economizer and 

additional expansion valve for refrigerant 

vapour injection. 

COMPRESSOR 





Units are also supplied with economizer 







Each scroll compressor used in the LWZ 













the performance gains with this system 

compared to any other compressor tech- 

nology. The compressors are all supplied 


protection by a klixon embedded in 

the motor winding. They are mounted in a 

separate chamber in order to be separated 

from the air stream. The crankcase heater 

is always powered when the compressor 

is in stand-by. The inspection is possible 

through the frontal panel of the unit that allows 

the maintenance of the compressors 

even if the unit is working. 

AIR SOURCE HEAT EXCHANGER 

The source air heat exchangers are made 

of copper pipes and aluminium fi ns. The 

diameter of the copper pipes is 3/8” and the 










WATER SOURCE HEAT EXCHANGER 

Source water heat exchanger are made 


plates type. The use of this kind of heat 

exchangers allows a massive reduction of 

the refrigerant charge of the unit compared 

to the traditional shell-in-tube evaporators 

and also a reduction of the overall dimensions 

of the unit. The user heat exchangers 

are factory insulated with fl exible close cell 

material and the heat exchanger is provided 

with a temperature sensor as antifreeze 

protection. 

FANS 











USER HEAT EXCHANGER 

The user heat exchangers are made of 

AISI 316 stainless steel braze-welded 

plates type. The use of this kind of heat 

exchangers allows a massive reduction of 

the refrigerant charge of the unit compared 

to the traditional shell-in-tube evaporators 

and also a reduction of the overall dimensions 

of the unit. The user heat exchangers 

are factory insulated with fl exible close cell 

material and can be equipped with antifreeze 

heater (optional). Each heat exchanger 

is provided with a temperature sensor as 

antifreeze protection. 

ELECTRIC BOX 



and 89/336. The accessibility to the board is 

possible after removing the front panel of the 

unit. In all LWZ units is installed, standard, 

the compressors sequence relay which disables 










fan contactors, pump contactors. 


free contacts for remote ON-OFF , winter/ 

summer change over and general alarm. 


All LWZ units are supplied standard with 



















62

LWZ 


















fl ow switch. 

LWZ 

C.O.P. TREND COMPARISON BETWEEN LWZ HYBRID UNITS AND LZT UNITS. 

C.O.P. 

5,0 

4,5 

4,0 

3,5 

3,0 

2,5 

2,0 

-15 -10 -5 0 5 10 15 

°C 

Grafi c shows C.O.P. trend of LWZ units 

(Orange line) depending on external air 

temperature (with outlet user water at 35 

°C) compared to an equivalent LZT unit 

(Blu line). 

As you can see with the reduction of the 

external air temperature C.O.P., the difference 

increases. 

Higher C.O.P. difference is when external 

air reaches -15 °C. 

63 

www.hidros.it

LWZ 

LWZ 

LWZ 2 PIPES VERSION. 

This unit is able to produce cooled water 

in summer with the inversion cycle in the 

refrigerant circuit. 

LWZ/SW6 4 PIPES VERSION. 


domestic hot water the unit is supplied 

with an additional heat exchanger used 

as condenser for the domestic hot water 

which, is independent from the operation 

mode of the unit. 

64

LWZ 

Main switch 





LS00 

S1NT version with one pump, Brine source side, without tank. 

S1NT 


DSSE 


KAVG 


KAVM 


MAML 


VSLI 


PCRL 


INSE 


26 36 52 72 82 92 

LWZ 

Standard, 


LWZ 26÷36 LWZ 46÷82 

LWZ 92 


26/26A1 1406 1870 850 350/510 

36/36A1 1406 1870 850 390/550 

46/46A1 1759 2608 1105 660/810 


52/52A1 1759 2608 1105 710/880 

72/72A1 1842 2608 1105 725/895 

82/82A1 1842 2608 1105 810/980 

92/92A1 1842 3608 1105 1070/1280 

65 

www.hidros.it

LPH 

Swimming pools heat pumps 

LPH 

TITANIUM 

The LPH heat pump series represents the most effi cient solution 

for the heating of the outdoor swimming pools in those 

periods in which the solar irradiation is not suffi cient. 

The units have been designed to operate down to -5°C ambient 

temperature. 

OTHER VERSION 

• LPH Only heating. 

ACCESSORIES 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 


Evaporation/condensation pressure control by pressure 

transducer and fan speed control (Standard). 




Condensing coil protection mesh with metallic filter. 

Condensing coil corrosion-proof treatment. 




heater. 

66

LPH 

Model LPH 06 09 13 

Heating capacity (1) kW 8,0 12,0 18,0 

Compressor input power (1) kW 1,5 2,2 3,2 

Power supply V/Ph/Hz 230/1/50 400/3+N/50 

Nominal input current A 9,4 13,0 10,0 

Peak current A 62,0 100,0 67,0 

Maximum input current A 16,0 25,0 15,0 

Air fl ow m 3 /h 3000 3000 5000 

Fans / input power n°x Kw 1 x 0,28 1 x 0,28 2 x 0,28 

Compressors / n° / circuits type/n° Scroll/1 Scroll/1 Scroll/1 

Sound power level (2) dB(A) 68 68 69 

Sound pressure level (5) dB(A) 40 40 41 

Pool maximum water volume m 3 0 ÷ 50 50 ÷ 80 80 ÷ 140 

LPH 

(1) 

Heating: Ambient temperature 15°C; water temperature 30°C. 

(2) 

Power sound level to according ISO 3746. 

(3) 

Sound pressure level at 10 mt from the unit in free fi eld conditions direction factor Q=2, according to ISO 3746. 

67 

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LPH 

LPH 

FRAME 

All LPH units are made from hot-galvanised 





removable panels. All screws and rivets are 

in stainless steel. The colour of the units is 

RAL 7035. 









valve with external equalizer, reverse cycle 

valve, one-way valves, liquid receiver, 

Schrader valves form maintenance and 

control, pressure safety device (according 

to PED regulation). 

COMPRESSORS 

The compressors are scroll type with crankase 


by a klixon embedded in the motor 

winding. The compressors are mounted 

on rubber vibration dampers and they can 

be supplied wih sound attenuation jacket 

to reduce the noise emission (option). The 

compressor crankcase heater is always 

powered when the unit is in stand-by. The 

inspection on the compressors is possible 

only through the unit front panel. 

SOURCE EXCHANGER 

The source exchangers are made of copper 

pipes and aluminium fi ns. The diameter of 

the copper pipes is 3/8” and the thickness of 

the aluminium fi ns is 0,1 mm. The tubes are 

mechanically expanded into the aluminium 

fi ns to improve the heat exchange factor. 

The geometry of these heat exchangers 

guarantees a low air side pressure drop 

and then the use of low rotation (and low 

noise emission) fans. The evaporators can 

be protected by a washable metallic fi lter to 

be installed on request. 

FAN 

The fans are in aluminium, axial type. They 

are statically and dynamically balanced and 

supplied complete of the safety fan guard 

according to EN 60335. They are mounted 

on the unit frame by interposition of rubber 

vibration dampers. The electric motors are 

6 poles (about 900 rpm). The motors are 

connected to the fans by pulleys and belts. 

The protection class of the motors is IP 54. 

USER EXCHANGER 

The user exchangers are shell-in-tube type 

with Titanium heat exchanger and external 

shell in PVC. These heat exchangers have 

been designed to have a very low difference 

betweeen inlet and outlet temperature; 

this allows to treat high waterfl ows and reduce 

the setup time of the system. 

MICROPROCESSOR 

All LPH units are supplied standard with microprocessor 





automatic starting sequence, alarm reset, 

alarms and operation leds. The microprocessor 

is set to allow the defrost operation 

automatically. 

ELECTRIC BOX 



and 89/336. The accessibility to the board 

is possible after removing the frontal panel 

of the unit. The protection degree is IP55. 

In all LPH units are installed, standard, the 

compressors sequence relay which disables 










fan contactors. The terminal board 

is supplied with voltage free contacts for 

remote ON-OFF , Summer / winter change 

over (heat pumps only) and general alarm. 



control and protection devices: Return water 

temperature sensor, installed on the return 

water line from the plant, high pressure 

switch with manual reset, low pressure 

switch with automatic reset, high pressure 

safety valve, compressor thermal overload 

protection, fans thermal overload protection, 

pressure transducer. 

68

LPH 

Model LPH Codice 06 09 13 

Main switch 



Evaporation/condensation pressure control by pressure transducer and fan speed control 





Condensing coil protection mesh with metallic fi lter 




Condensing coil corrosion-proof treatment 

LS00 

KAVG 

KAVM 

MAML 

FAMM 

DSSE 

PCRL 

BRCA 

Contact the Company 

LPH 


Outlet water temperature (°C) 

50 

40 

30 

20 

-10 0 10 20 30 40 

Ambient temperature(°C) 

LPH 06 - 09 LPH 13 


06 989 1145 380 97 

09 989 1145 380 120 

13 1324 1245 423 135 

69 

www.hidros.it

HIDROS 

12 

15 

4 

7 7 13 

2 6 

5 

11 

8 8 

5 

9 

10 1 

16 

3 

5 

14 

1 Heat Pump. 10 User storage tank. 

2 D.H.W. Cylinder. 11 User sensor. 

3 User pump. 12 Air handling unit - Dehumidifcation. 

4 External Sensor. 13 Air handling unit pump. 

5 Expansion valve. 14 Solar panel pump. 

6 D.H.W sensor. 15 Solar panel. 

7 Underfl oor heating system pump. 16 Solar panel heat exchanger. 

8 Mixing valve. 17 

9 3 Way valve (Heating / Cooling / Domestic hot water). 18 

TABLE 1: AIR TO WATER HEAT PUMP SYSTEM 

SE 

70

12 

15 

7 7 13 

2 

6 

11 

8 8 

10 

16 

5 

14 


2 D.H.W. storage tank. 11 User sensor. 

3 User pump. 12 Air handling unit - Dehumidifcation. 

4 External sensor. 13 Air handling unit pump. 

5 Expansion vessel. 14 Solar panel pump. 

6 D.H.W sensor. 15 Solar panel. 

7 Underfl oor heating system pump. 16 Solar panel heat exchanger. 


9 D.H.W pump. 18 


5 

9 

3 

HIDROS 

4 

1 

SE 

71 

www.hidros.it

HIDROS 

12 

4 

13 

2 

6 

7 7 

5 

11 

8 8 

5 

10 1 

9 

3 


2 D.H.W. Storage Tank. 11 User sensor. 

3 User pump. 12 Air handling unit - Dehumifi cation. 


5 Expansion vessel. 14 

6 D.H.W. sensor. 15 

7 Underfl oor heating system pump. 16 




SE 

72

12 

2 

8 

8 

13 

6 

5 

11 

9 

9 

5 

10 


2 D.H.W. Storage Tank. 11 User sensor. 

3 User pump. 12 Air handling unit - Dehumifi cation. 

4 External sensor. 13 Air handling pump. 





9 D.H.W. Pump. 18 


9 

3 

4 

1 

HIDROS 

SE 

73 

www.hidros.it

2 

7 

7 

5 

8 8 

1 Heat pump. 10 

2 D.H.W. Cylinder. 11 

3 User pump. 12 

4 External sensor. 13 







6 

5 

9 

3 

HIDROS 

4 

1 

SE 

74

2 

7 

7 

5 

8 8 

1 Heat pump. 10 

2 Puffer. 11 







9 D.H.W. pump. 18 


6 

5 

9 

3 

4 

SE 

1 

HIDROS 

75 

www.hidros.it

12 

7 

7 

6 

13 

5 

11 

8 8 

2 

5 

10 

1 Heat pump. 10 User storage tank. 


3 User pump. 12 Air handling - Dehumidifi cation. 


5 Expansion vessel. 14 Heat station domestic hot water. 

6 D.H.W sensor. 15 



9 D.H.W. pump. 18 


14 

9 

3 

HIDROS 

4 

1 

SE 

76

12 

16 

7 7 13 

6 

5 

11 

8 8 

5 

2 

10 

5 

15 

1 Heat pump. 10 User storage tank. 


3 User pump. 12 Air handling unit - Dehumidifi cation. 


5 Expansion vessel. 14 Heat station domestic hot water. 

6 D.H.W sensor. 15 Solar panel pump. 

7 Underfl oor heating system pump. 16 Solar panel. 


9 D.H.W. pump. 18 


14 

9 

3 

HIDROS 

4 

1 

SE 

77 

www.hidros.it

HIDROS 

13 

16 

5 

SE 

8 8 14 

2 

7 

6 

12 

9 9 

6 

10 

4 

11 

1 

3 

6 

15 

1 Heat pump. 10 3 Way valve (Heating / Cooling / Domestic hot water). 

2 D.H.W. cylinder. 11 User storage tank. 

3 User pump. 12 User sensor. 

4 Source pump. 13 Air handling unit - Dehumidifi cation. 



7 D.H.W. sensor. 16 Solar panel. 



TABLE 1: GROUND SOURCE HEAT PUMP SYSTEM 

78

13 

16 

8 8 14 

2 

7 

6 

9 9 

12 

6 

10 

11 

6 

3 

15 

1 Heat pump. 10 D.H.W. pump. 

2 D.H.W. storage tank. 11 User storage tank. 









5 

1 

SE 

4 

HIDROS 

79 

www.hidros.it

HIDROS 

13 

5 

SE 

8 

8 

12 

9 9 

14 

2 

7 

6 

6 

1 

10 

4 

11 

3 


2 D.H.W. Cylinder. 11 User storage tank. 









80

13 

5 

SE 

8 8 14 

2 

6 

12 

9 9 

7 

10 

6 

1 

11 

3 

1 Heat pump. 10 D.H.W. sensor. 

2 D.H.W. Cylinder. 11 User storage tank. 









4 

HIDROS 

81 

www.hidros.it

HIDROS 

5 

SE 

8 

8 

7 

6 

2 

9 9 

6 

10 

1 

4 

3 


2 D.H.W. Cylinder 11 


4 Source pump. 13 







82

5 

SE 

8 

8 

7 

6 

2 

9 9 

6 

10 

1 

3 


2 D.H.W. Cylinder 11 


4 Source pump. 13 







4 

HIDROS 

83 

www.hidros.it

13 

5 

8 8 14 

7 

12 

9 9 

6 

2 

6 

10 

1 

11 

3 





5 Heat station Domestic hot water 14 Air handling unit pump. 






SE 

HIDROS 

4 

84

13 

16 

5 

8 8 

12 

9 9 

14 

7 

6 

2 

6 

10 

11 

6 

3 

15 





5 Heat station Domestic hot water 14 Air handling unit pump. 

6 Expansion vessel. 15 Solar panelpump. 





1 

SE 

4 

HIDROS 

85 

www.hidros.it

HIDROS 

DESCRIPTION TABLE 1 

Two pipes system heat pumps. 

Cooling and heating system working with 

a heat pump unit, with domestic hot water 

solar integration. The heat pump produces 

hot water at low temperature (e.g. 35 °C) 

for heating system, and switches the position 

of a 3 way valve to drive hot temperature 

water (max 60 °C) when domestic hot 

water production is requested. The 3 way 

valve control is done by the unit electronic 

board. 

During cooling operation, if domestic hot 

water is requested, the unit reverses refrigerant 

cycle and switches the position of 

the 3 way valve to supply hot water to the 

domestic water tank. 

The heat pumps are supplied with domestic 

hot water probes and with weather compensation 

sensor. 

The domestic hot water is produced with a 

boiler fi tted with an oversized spiral coil, in 

which the water coming from the heat pump 

fl ows. The buffer tank is used during cooling 

or heating mode, to reduce start and 

stop unit cycle, especially if the plant regolation 

system is equipped with motorized 

valves on all circuits that could reduce the 

water fl ows on secondary circuits. The solar 

integration is obtained installing a heat 

exchanger in the lower part of the boiler. 

Water to water heat pump can be supplied 

on request, with another plate heat ex- 

changer (built inside the unit), for free cooling 

operation during summer, when cold 

source temperature (well or ground) is near 

to the cooling set point. 


Four pipes system heat pumps. 



and solar integration. The heat pump 

produces separately hot water at low temperature 

( e.g. 35 °C) for heating system 

and hot water at high temperature (max 60 

°C) when domestic hot water production is 

requested. 


water is requested, the units supply hot 

water to the domestic water tank without 

reversing refrigerant cycle. The heat pumps 

are supplied with water tanks, temperature 

probes and with weather compensation 

sensor. 





or heating mode, to reduce start and stop 

unit cycle, especially if the plant regolation 

system is equipped with motorized valves 

on all circuits that could reduce water fl ows 

on secondary circuits. 

The solar integration is obtained installing a 

heat exchanger in the lower part of the boiler. 


on request, with another plate heat 

exchanger (built inside the unit), for free cooling 








production. The heat pump produces hot 

water at low temperature (e.g. 35 °C) for 

heating system, and switches the position 

of a 3 way valve to drive hot temperature 

water (max 60 °C) when domestic hot 

water production is requested. The 3 way 

valve control is done by the unit electronic 

board. 


water is requested, the unit reverses the 

refrigerant cycle and switches the position 

of the 3 way valve to supply hot water to 

the domestic water tank. The heat pumps 



sensor. 

Domestic hot water is produced with a 




or heating mode, to reduce start and 

stop unit cycle, if the plant regolation system 

is equipped with motorized valves on 

all circuits that could reduce water fl ows 

on secondary circuits. Water to water heat 

pump can be supplied on request, with 

another plate heat exchanger (built inside 

the unit), for free cooling operation during 

summer, when cold source temperature 

(well or ground) is near to the cooling set 

point. 

86





production. The heat pump produces separately 

hot water at low temperature ( e.g. 

35 °C) for heating system and hot water at 

high temperature (max 60 °C) when domestic 

hot water production is requested. 







sensor. 





or heating mode, to reduce start and stop 

unit cycle, especially if the plant regolation 

system is equipped with motorized valves 

on all circuits that could reduce water fl ows 

on secondary circuits. 


on request, with another plate heat exchanger 

(built inside the unit), for free cooling 

operation during summer, when cold source 

temperature (well or ground) is near to the 

cooling set point. 

HIDROS 



Heating system working with a heat pump 

unit, with domestic hot water production. 

The heat pump produces hot water at low 

temperature (e.g. 35 °C) for heating system, 

and switches the position of a 3 way 

valve to drive hot temperature water (max 

60 °C) when domestic hot water production 

is requested. The 3 way valve control is 

done by the unit electronic board. 

The heat pumps are supplied with water 

tanks, temperature probes and with weather 

compensation sensor. 

Domestic hot water is produced with a 

boiler fi tted with an oversized spiral coil, 




a heat pump unit, with domestic hot water. 

The heat pump produces separately hot 

water at low temperature ( e.g. 35 °C) for 

heating system and hot water at high temperature 

(max 60 °C) when domestic hot 

water production is requested. 

The heat pumps are supplied with water 

tanks, temperature probes and with weather 

compensation sensor. 




fl ows. 

in which the water coming from the heat 

pump fl ows. The buffer tank is used during 

heating mode, to reduce start and stop unit 

cycle, especially if the plant regolation system 


all circuits that could reduce water fl ows 

on secondary circuits. The solar integration 

is obtained installing a heat exchanger in 

the lower part of the boiler. Water to water 

heat pump can be supplied on request, with 

another plate heat exchanger (built inside 

the unit), for free cooling operation during 

summer, when cold source temperature 

(well or ground) is near to the cooling set 

point. 







87 

www.hidros.it


HIDROS 



a heat pump unit, with domestic hot water. 

The heat pump produces separately hot 

water at low temperature ( e.g. 35 °C) for 

heating system and hot water at high temperature 

(max 60 °C) when domestic hot 

water production is requested. 







sensor. 

The domestic hot water production is obtained 

using an instant plate heat exchanger 

(heat station) that uses the higher tempera- 

ture in the upper side of the domestic water 

tank. 

When the hot water user tap opens the 

fl ow switch installed on piping starts up the 

pump. The water fl ows through the heat exchanger 

and transfers the heat to the city 

water. 

The buffer tank is used during cooling or 




all circuits that could reduce water fl ows on 

secondary circuits. 









Cooling and heating system working with a 

heat pump unit, with domestic hot water solar 

integration. The heat pump produces separately 

hot water at low temperature ( e.g. 

35 °C) for heating system and hot water at 

high temperature (max 60 °C) when domestic 

hot water production is requested. 







sensor. 

The domestic hot water production is obtained 

using an instant plate heat exchanger 

(heat station) that uses the higher temperature 

in the upper side of domestic water 

tank. 

When the hot water user tap opens the 

fl ow switch installed on piping starts up the 

pump. The water fl ows through the heat exchanger 

and transfers the heat to the city 

water. 

The buffer tank is used during cooling or 




all circuits that could reduce water fl ows on 

secondary circuits. 

The solar integration is obtained installing 

a heat exchanger in the lower part of the 

boiler. 







88

Dehumidifiers 

Heat 

Pumps 

C h i l l e r s 

HIDROS S.r.l 

Via dell'industria, 5 - 35020 Brugine (PD) 

Tel +39 049 9731022 - Fax +39 049 5806928 

www.hidros.it - info@hidros.it

WDH WDH

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