Article. Energy in fokus - from Kyoto to Copenhagen. - AgroTech

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Article. Energy in fokus - from Kyoto to Copenhagen. - AgroTech

Figure 2. Dynamic climate control tomato trials in France. Energy

consumption and saving in 2006-2007. At IT1 the Temperature

integration had 2-5°C extra space from highest/lowest setpoints,

compared to control. At IT2 it was 3-8°C.

She described that the essential element

in energy effectiveness by change in

climate control is to allow big difference

between highest and lowest temperature

in a “band-width”, to allow higher humidity

level, and to use dynamic changes of

the setpoints in the control.

It was stated that results from several

trials where many different cultivars were

used, show that most cultivars are tolerant

to temperature fluctuations, if you assure

to keep track of the average temperature

by using temperature integration control.

This is well known knowledge, but here

Anja Dielemann said that this assumption

is based on documentation from research,

and not just a “rule of thumb”. Results

from some trials show energy saving from

3% to 13% using a band-width on 10°C

in the temperature integration control, as

an example from the research in Holland.

Low temperature for Anthurium

grown in Belgium

If you want to use dynamic climate control

you have to decide the limit for the

allowed, lowest temperature. This can be

due to the danger of leaf wetness caused

by high humidity, if the humidity control

can’t catch up with the temperature

fluctua-tions. It can also depend on which

temperature tolerance the cultivars are

“born with” from their origin, and still not

loosing quality.

Trials that should help to state the

lowest acceptable temperature were

described on a poster from Els Storme et.

al. from Belgium.

Growing Tropical plants often requires

fairly high temperatures, therefore energy

use can be high. Therefore it is especially

important to try to save energy, for

example by using dynamic climate control

with low temperature setpoints. But how

low? The trials were made on Anthurium

‘Limoria’ (C3 plant), set in different temperature

regimes, from high to low. Measuring

on different processes in the crop,

they found that temperatures under 12°C

did affect the processes negative.

High temperature for poinsettia

On the other hand you also have to get

to fairly high temperature, especially in

Research from different places shows that it is also possible to use dynamic

climate control in tomatoes if you choose appropriate setpoints.

Anthurium. Research shows that the processes in the

plant are affected at temperatures below 12°C.

the middle of the day, where you can harvest

more free energy form the sun if you

allow high temperatures. But you can also

decide to use high temperatures if you can

buy cheep energy in certain periods.

In Germany there has been trials on this

for Poinsettia. N. Gruda et. al. used day/

night setpoints fixed on 25°C/16°C, plus

a period in the morning using even lower

temperature (12°C).

The control day/night were 18°C/16°C.

Results were good. Plant quality was good,

with bigger leaf area and same height

development, although they became a

little higher. Conclusion was that it is possible

also to use higher temperatures to

produce good quality poinsettia, in periods

where you have “luxury heat”, cheap

or free, and thereby save energy and/or

money.

Dynamic climate control

will remain

The elements from dynamic climate control

are described in an article by the

present writer in Gartner Tidende no. 12

from June 2009. A wide range of results

from research in other countries supports

that dynamic climate control works, gives

energy savings and states that the climate

control course in Denmark is right.

In several of the projects, described in

other articles in this magazine, is dynamic

climate control involved. One example

is from the project “Intelligent use of

energy”, where the climate control in

the demonstration greenhouse at “Hjortebjerg”,

Funen, is including the “Intelligrow”

climate control concept.

In my opinion we are going in the right

direction, but to be backed up by research

results from all over the world confirms

the concept. Dynamic climate control has

come and will remain.


ENERGY IN FOCUS 25

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