Wednesday, July 25, 2012
Pursuant to my bleg the other day, the above (from this marketing brochure) shows the degradation of nameplate heat movement capacity for two current models of Mitsubishi air-source heat-pump as the outside temperature drops.
Indeed this would seem to be pretty viable for cold climates - such as mine in Ithaca, NY:
Here, a typical January night is 15oF and a really cold night is 0oF at which point the heat pump is only slightly degraded in its ability to deliver heat. However, the above chart shows the record low as -25oF so I suppose a supplementary system would be needed to handle that.
Also of interest is this comparison of ground-source and air-source heat-pumps. The ductless mini-splits seem to be getting a good reputation for being relatively fool-proof and reliable, and the upfront cost is much lower than ground source heat pumps.