IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration
Subtask A Report, Date:…
4.2 Period of Measurement
Every data are measured and saved in daily “historic” files with a time scale 30 seconds.
These files were downloaded and analyzed frequently about every week.
The data available for the Task 38 monitoring is only the summer 2009 (from June to
September). Unfortunately, after this date a few issues prevented us to get the monitoring
data (problems with the building owner, and it was not possible to get the monitoring data
because of the Sonnenklima insolvency).
5 Monitoring Results
5.1 Annual / Monthly Data
The table below shows the energies considered in each loop of the installation. It also shows
some of the main performance factors calculated monthly and yearly for the monitoring
period:
Yearly June July August September
Energy
[kWh]
Energy
[kWh]
Energy
[kWh]
Energy
[kWh]
Energy
[kWh]
Total Electricity Consumption 351,9 115,0 82,2 84,3 70,4
solar irradiation on collector aperture area 8516,9 3519,0 1584,4 1727,5 1686,0
solar thermal output to hot storage 3404,6 1387,9 795,3 607,3 614,1
hot storage input to cooling machine (ACM) 1693,3 511,9 346,5 447,0 387,8
cold output ACM to cold-storage 915,5 271,0 167,3 252,4 224,8
cold storage output to cold-distribution 869,8 257,5 158,9 239,8 213,6
[-] [-] [-] [-] [-]
Collector efficiency (-) 0,40 0,39 0,50 0,35 0,36
Thermal COP (-) 0,53 0,48 0,56 0,58 0,53
Electrical COP (-) 2,24 1,93 2,84 3,03 2,24
During the considered monitoring period about 900 kWh of cold was produced and supplied
to the building. The collector efficiency were about 0,40 which is good, but expected because
the collectors are evacuated tubes collectors. The performance of the chiller is correct,
indeed the yearly average of the thermal COP reaches 0,53. On the other hand, the
electrical COP is a little bit lower than it could be expected: the average of the electrical COP
for this cooling period reaches 2,24 which is not bad because only the cooling period was
considered, but it could be better for a solar cooling installation. Actually this value of
electrical COP can be explained because of the use of a drycooler to reject the heat. Indeed
its two fans are consuming more than a conventional cooling tower, but it was the only
affordable way to avoid every legionella risk.