Propane (R-290) for heat pumps?

[AC_Hacker]

Originally Posted by Xringer

Yeepee, the 2011 Annex 32 Reports are out!

What did you learn?

I did notice this in the second listed report, in section 7 (page 13):

In Japan, the design of heat pump air conditioners of single or multi-split type, which are the Japanese standard heating and cooling systems in the moderate climate zone, used to be a simple catalogue method, which led to over dimensioned systems with lower performance in low energy houses.

(emphasis added)

I mention this because I have noticed that you always advise people who are reading your threads to oversize their mini-splits, because the unit will run in reduced capacity when needed.

I think your advice is leading people who might trust you to select less efficient systems, in a similar way to the above quote regarding practices in Japan.

My advice is to do a load analysis, then select a heat pump unit that is slightly smaller than required, and use a secondary heat source under the extreme conditions.

Regards,

-AC_Hacker