Glossary · Heating, cooling & ventilation
HSPF / HSPF2
Also called: heating seasonal performance factor
A heat pump's heating efficiency averaged over a whole heating season; higher is better, and HSPF2 numbers can't be compared directly with older HSPF.
What it means
HSPF2 replaced HSPF in 2023 when US test procedures changed, and DOE says the old and new numbers aren't directly comparable. Ratings also depend on the climate assumed: Region IV represents a US Midwest-type climate, while Region V is colder, closer to Ottawa. Dividing HSPF by 3.412 gives an approximate seasonal COP.
Why it matters in an audit
It's the main heating-efficiency number on heat pump spec sheets, rebate rules and AHRI certificates.
Typical numbers
Reference values with their sources. Your energy advisor’s report gives the figure for your own house.
| What | Value | Source |
|---|---|---|
| ENERGY STAR (spec 6.2) | Split ≥ 7.8; single-package ≥ 7.2; Cold Climate ≥ 8.5 ductless or ≥ 8.1 ducted | energystar.gov ↗ |
| NEEP cold-climate spec v4.0 | Above 7.7 ducted; above 8.5 ductless | neep.org ↗ |
| NRCan guide (older HSPF metric, Region V) | Canadian minimum 7.1; market range 7.1–13.2 | natural-resources.canada.ca ↗ |
In Canada
NRCan's heat pump lists show HSPF2 for Region V, which better reflects much of southern Canada; NRCan notes real seasonal efficiency is lower in colder regions.