The first one is multi-split MSX18, the second is commercial VRV-III-S. Both graphs are for the 20C indoor temperature. They show that, although decreasing, the performance is still high enough to supply heat even at -15C and probably down to -20C. When indoor temperature can be allowed to be lower (like in the example of the garage for fire trucks), or if it can be supplemented with back-up source (e.g. infrared radiant heaters), the performance will be dropping even slower, remaining at or above 2.5 COP even under -20C.
Sunday, November 20, 2011
Air Heat Pump performance
As part of the sustainability efforts in general, and the energy-efficiency upgrade proposal for Sun Peaks fire hall in particular, I was trying to find the performance of the split systems we have chosen for that upgrade under low temperatures, which are common here. Not being able to find this information readily available, I contacted Daikin directly and was pleasantly surprised by their prompt response and their providing me with all the information I asked, and even more, including complete Engineering Reports on their units. As a result, I was able to chart these graphs, which give visual indication of the COP vs. outside temperature performance.