Can anyone tell how to figure the balance point of a
heat pump. I know what it is but cant find how to figure it
I found a site, progress-energy.com , that states, "The balance point is determined from the ACCA manual J load calculation and the system output capacity." , there was more but that was the gist of it. That answer is for the US, in Canada it is different but I will refrain as the mention of Canadian methods makes many site users uneasy.
Things you will need:
Manual J load calc.
Outdoor design temp.
Manufactuers spec sheet with btuh capacity and will be rated at 0, 17, 47, 65F (usually,may vary from mfg.) showing ARI rated capacity. (you may have to interpolate)
Find the intersection of your heat loss @ outdoor design and the output of the machine at that temp. That's your balance point.
Anything below that point requires supplemental heat.
Better yet hire a pro.
Above reflects only load balance point and not econimic balance point.
[Edited by steve3871m on 03-09-2005 at 01:24 AM]