What do HSPF2 and SEER2 actually mean?

What the “2” changed

HSPF2 and SEER2 replaced HSPF and SEER when the federal test procedure moved to the M1 method, which tests equipment against a higher external static pressure than the old procedure did. That is closer to a real duct system, so the new numbers are lower than the old ones for the same machine. Comparing a SEER2 figure against an old SEER figure makes new equipment look worse than it is.

Why HSPF2 matters more than SEER2 here

Zone 4C is heating-dominated, with most of the annual runtime spent heating and very little cooling demand. So the heating rating is the one tied to your actual bill, while the cooling rating is a secondary consideration for our 78°F cooling design temperature. A bid that leads with SEER2 in Bellingham is quoting the number that matters least.

What a seasonal rating cannot tell you

A seasonal average is computed over a modeled climate, not over your house at design condition. For the question that actually keeps a Whatcom homeowner warm, you want the rated heating capacity at 17°F, and at 5°F for cold-climate models, from the manufacturer’s published data. Efficiency and capacity are different things, and it is entirely possible to buy an efficient system that runs out of capacity when you need it.

Where the ratings turn into money

PSE’s midstream equipment discount is tiered by SEER2 and HSPF2, paying $300 to $600 through the distributor, so the rating band you buy into changes your out-of-pocket. Whether that discount stacks with the $1,500 conversion rebate is unconfirmed, so we will not add both into one number for you. Ask us for the AHRI certificate on whatever we quote, and check the ratings against the rebate tier yourself.