IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration
Subtask A Report, Date:…
Figure 3: Evacuated tube collector field at the main building of the Technical College
Butzbach. Also an effective shading of the rooms can be achieved by the assembly of the
collectors. Source: Fraunhofer ISE
3 Control Strategy
The control strategy of the system was realized by one of the project partners (Hindenburg
Consulting). Information on the strategy is not at hand.
The collector sub-control system for freezing protection runs independently from the overall
system control and was prepared by the collector manufacturer Paradigma.
4 Monitoring Equipment
4.1 Installed Equipment
For the system monitoring different measurement devices have been installed. Beside
several temperature and volume flow meters also the specific radiant power is measured by
the help of two irradiation pyranometers (CMP11); one in horizontal position and the other
one in the collector plane. The pressure in the collector circuit is measured as well. Ten
electricity meters record the electrical power input of pumps, absorption chillers, cooling
towers, air handling units and the controller (three-phase electricity counters with 1000
impulses per kWh). The operating hours from most pumps and some valve engines are
registered as well.
The devices to measure the volume flow rates are multiple-jet impeller water meters with
impulse transmitter. For measuring the temperatures in the system Pt100 temperature
sensors (accuracy 1/3 DIN class B) were installed.
The following figure 4 shows all measurement points in the system.