Definition
HSPF2 (Heating Seasonal Performance Factor 2) measures how efficiently a heat pump heats over a season under the current federal test method. The higher the HSPF2, the more heat the unit delivers per unit of electricity. It's the heating-side counterpart to SEER2, and the rating that matters most for Michigan homeowners considering a heat pump as a primary heat source.
Why this matters for your home
Because a heat pump runs hardest during our cold months, HSPF2 drives a big share of its operating cost. Pair a strong HSPF2 with a true cold-climate heat pump and proper sizing, and the system can carry most of a Grand Rapids winter efficiently.