What Is the Balance Point?

The balance point is the outdoor temperature at which a heat pump's heating output exactly matches the building's heat loss. Above it the heat pump can hold the house on its own; below it, output falls short and backup heat has to make up the difference.

Also called: thermal balance point · changeover temperature

Why it matters to you

Because eastern North Carolina winters are mild, a properly sized heat pump's balance point usually sits below most of the hours in the season, so the system carries the house on compressor heat for the great majority of the winter. A balance point set too high calls in expensive backup heat earlier than necessary.

What to do about it

On a dual-fuel system the changeover setting determines when the furnace takes over, and it is adjustable. If backup heat engages on mild days, ask for the balance point and changeover settings to be reviewed.