Definition
Seasonal efficiency ratings for cooling (SEER2) and heating (HSPF2) under updated DOE test procedures — used to compare heat pumps and AC in Washington.
Why did SEER become SEER2?
In 2023 the Department of Energy switched to a tougher test that simulates real ductwork static pressure instead of ideal lab conditions. The same physical unit scores roughly 4–5% lower under SEER2 than under the old SEER test, so a 'SEER 16' from an old quote and a 'SEER2 15.2' can be the same machine. When comparing bids, make sure every quote uses the same rating generation.
Which number matters more in western Washington — SEER2 or HSPF2?
HSPF2. Our summers are short and our heating season runs most of the year, so the heating-efficiency rating drives the bills a heat pump actually produces here. A high HSPF2 cold-climate model earns its price back in heating mode; chasing the highest SEER2 mostly pays off in hotter climates.
Do rebates depend on these ratings?
Directly. Utility rebate tiers are written as minimum SEER2/HSPF2 thresholds (or as qualified-product lists built from them), and the cold-climate heat pump programs pay for verified low-temperature performance. Two quotes with different equipment tiers can carry very different rebate lines — so compare the after-rebate math, not the sticker efficiency alone.
In the Puget Sound
Washington sits in the DOE 'North' region: new central ACs must meet at least 13.4 SEER2, and current federal minimums for heat pumps are 14.3 SEER2 / 7.5 HSPF2 — utility rebates typically require better than the minimum.
Related terms
Go deeper on SEER2 / HSPF2
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Trade: Heating & Air