Air source heat pumps in Canada: what the rebates pay and what the sizing has to be

Cold-climate air source heat pumps carry the largest per-measure rebates in most Canadian programmes and are the measure most likely to disappoint if the sizing is wrong. Both facts have the same cause: the economics depend entirely on the unit running at part load for most of the winter.

What is on the table

Ontario's Home Renovation Savings pays up to $7,500 for a cold-climate air source heat pump and up to $12,000 for ground source. BC Hydro pays up to $4,000, and CleanBC pays up to $13,000 — but CleanBC is income-qualified as of 2026, which a great deal of BC marketing has not caught up with. Alberta's CEIP municipalities will finance the whole thing over up to twenty-five years.

The sizing problem

An oversized heat pump short-cycles, runs at its least efficient operating point, wears out sooner and frequently costs more to run than the furnace it replaced. Canadian residential equipment is oversized as a matter of routine, usually by a rule of thumb applied to floor area.

The correct answer comes from a CSA F280 heat loss and heat gain calculation, room by room, which is what the building codes actually require and what a permit reviewer asks for. Note that HOT2000 does not qualify for F280 — different calculation, different purpose, routinely rejected.

Do the envelope first, if you can

Every kilowatt of heating load you remove from the house is a smaller, cheaper heat pump that runs closer to its sweet spot. Air sealing and attic insulation before the equipment is not just better building science; it is a smaller capital cost on the equipment itself.