Defrost calculation and impact on output

[JohnMo]

Looking at a technical manual today, HiSense monobloc, and split system. It gives all the parameters to help size the heat pump and for the first time I have seen a manufacturer take due diligence for defrost. Giving derate required for various outside temps

 

[Beelbeebub]

That's good, thought they ought to include that in the main table figures rather than as an extra. That way they could include the cop. 

 

I have seen various ways of showing the performance of HPs but the best (IMHO) is to have a outside temp / flow temp table with each "cell" giving power, input power and cop.  It then had 3 tables giving those figures at the maximum, most efficient and lowest outputs. There was some shading on the cells where output was being affected by defrost. 

 

That would seem to give all the info needed. 

[JohnMo]

5 minutes ago, Beelbeebub said:

maximum, most efficient and lowest outputs.

I was looking at a Haier heat pump tech data, they had all the outputs for all outside temps and flow temps, and min, middle, nominal and max output for each data point.

 

Trouble most manufacturers don't give this level of detail.