IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration
Subtask A Report, Date:…
Figure 8 shows the share of all devices in electricity consumption. It can be seen that heat
rejection and the associated pump make up almost two thirds of the entire electricity
consumption. Hot and cold water pumps together with the control device account for almost
all the rest. The pumps in the solar cycle I and II are the only energy saving pumps and they
are also the only speed controlled pumps in the solar cooling system. A lot of electricity could
have been saved by equipping the entire system with energy saving pumps. However, some
additional improvements may be made by operating the pumps connected to the chiller at
variable speeds instead of steady flow.
The control system also exhibited a surprisingly high energy use. Monitoring showed a
constant consumption of 40 W, which is definitely higher than many other control systems
available in the market. The cooling tower is by far the biggest consumer of all electrical
components.
Interestingly enough, monitorings uncovered a random consumption of the cooling tower of
constant 130 W on top of the regular consumption during operation times. There is no
indication of a stand-by mode and speculations about an incorrectly wired anti-freeze
element turned out to be wrong. So far, it has not been clarified what really causes the extra
electricity consumption.