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Sequence of Operation
Natatorium
Sequence of Operation for DS/RS One Compressor Unit
with Purge Mode Configuration
Supply Air Blower
Blower operation is continuous to prevent
humidity stagnation. It can be
remotely controlled by a Building
Management System (BMS) signal.
Blower stops and all (optional) motorized
dampers close on:
•power failure
•firestat alarm
•freezestat alarm
•remote off control
(manual or from BMS)
Exhaust Air Blowers (EF1 & EF2)
Blowers can be unit mounted or
remote.
EF1 blower operation is continuous or
can be controlled by an occupied/unoccupied
signal from the BMS, a
seven-day time clock or through the
microprocessor in the DRY-O-TRON®.
EF1 exhausts 10% more air than is
introduced through the outdoor air
opening at minimum set point to
maintain a negative space pressure.
EF2 operates only on call for Purge
mode or Economizer mode.
Blowers stop and all (optional) motorized
dampers close on:
•power failure
•firestat alarm
•freezestat alarm
•remote off control
(manual or from BMS)
Outdoor Air Damper
Standard manual damper is normally
closed (unoccupied mode).
On an occupied signal from the sevenday
time clock, the damper opens to
the minimum set point. Outdoor air is
introduced to meet local code requirements.
On Purge mode signal, the damper
opens fully to allow 100% outdoor air
into the DRY-O-TRON®.
All motorized dampers close on supply
air blower stop.
Dehumidification Mode
Dehumidification mode occurs when
the room relative humidity rises above
set point (i.e. 50% RH).
• The outdoor air sensors on DOTICS-
9 controller only, (temperature and
% RH) will verify if Economizer
dehumidification is possible.
• If outdoor air is not suitable for
Economizer operation, the compressor
starts to operate in “dehumidification
and hot gas reheat mode".
The hot gas reheat coil is energized.
Pool Water Heating Mode
Pool water heating mode occurs when
the pool water temperature drops
below set point.
• If the compressor is already operating
in dehumidification or cooling
mode, the compressor hot gas is
used for water heating.
• If all room conditions are satisfied,
or if there is a call for second-stage
pool water heating, the microprocessor
will send a signal to the
auxiliary pool water heater to maintain
water temperature.
• Dectron Inc.’s Water Smart Design
will ensure compressor operation in
dehumidification mode. Cooling
mode is never interrupted by a lack
of water flow to the unit.
• Should water flow be interrupted,
the microprocessor will lock out
water heating mode and display
“low water flow" message on the
operator panel. All other modes of
operation will operate normally.
Cooling Mode
Cooling mode occurs when the space
temperature is above set point.
• The outdoor air sensor verifies if
Economizer cooling is possible.
• If outdoor air is not suitable for
Economizer cooling, the compressor
starts to operate in “cooling mode".
Both the outdoor air-cooled and
water-cooled condensers reject the
compressors’ Total Heat of Rejection
as required.
Economizer Mode
Economizer mode will operate whenever
outdoor conditions permit and
override compressor operation.
• If cooling is called for, the microprocessor
will verify that the outdoor
temperature is suitable. If yes,
and the outdoor humidity level is
neutral to the space, the unit will
operate in Economizer cooling
mode.
• If dehumidification is called for, the
microprocessor (DOTICS-9 only) will
verify that the outdoor moisture
level is suitable. If it is and the outdoor
temperature is neutral to the
space, the unit will operate in
Economizer dehumidification.
• During Economizer mode, the
motorized O/A damper opens to
100% and R/A dampers (evaporator
face and bypass damper) fully close.
Supply fan and exhaust fans (EF1
and EF2) ventilate the space with
100% outdoor air.
Space Heating Mode
Heating mode occurs when the space
temperature drops below set point.
• If the room temperature drops below
set point, the DRY-O-TRON®’s
microprocessor will send a signal to
a space-heating coil (factory mounted
or remote) to maintain space
temperature.
• Optional unit mounted heating coil
freeze protection mode. If the heating
coil’s average leaving air temperature
falls below 45°F/7.2°C
(adjustable), the blowers shut down,
all dampers close and the control
valves will fully open.
Purge Mode
Purge mode occurs on a call for Purge
mode from DRY-O-TRON® operator
panel or remote push button (by others)
momentary signal. This timeroperated
mode (2-20 minutes) is
intended to ventilate the space with
one complete air change and then
automatically resume normal operation.
• DRY-O-TRON® compressors are
stopped.
• Face and bypass dampers on evaporator
coil close fully.
• Outdoor air damper opens fully to
allow 100% outdoor air into the
DRY-O-TRON®.
• EF1 and EF2 operate to evacuate
maximum air flow from the space.
• The space heating coil will temper
the supply air as required.
ENERGY RECYCLING DEHUMIDIFIERS & POOL WATER HEATERS FOR NATATORIUMS
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