I understand HSPF is fundamentally the same thing as SEER, only it's
representing a heating season instead of a cooling season.

When handling SEER, I used the following equation to come up with a
seasonally averaged cooling EER:

EER = SEER * 0.875

My limited understanding is that 0.875 is a conceptually a constant
representing a "part load cycling factor" of sorts for a typical cooling
season. I've read multiple times this constant should vary with climate
(commonly, "Georgia = 0.8" and "California = 0.9"). While that makes
sense to me, I've yet to see a citable climate map or similar reference
breaking down what factor to use where... so up to this point I've stuck
with 0.875 for simplicity's sake.

My root question is: Is there a comparable "part load cycling factor,"
for one or more climates, for converting HSPF to a seasonally averaged
heating COP/EER?

Put another way: EER = HSPF * ???

NICK CATON, E.I.T.