Glossary · Heating, cooling & ventilation
Balance point
Also called: thermal balance point · economic balance point · switchover temperature · changeover temperature
The outdoor temperature where something changes: below the thermal balance point a heat pump needs help; below the economic one, fuel is cheaper.
What it means
The thermal balance point is where the heat pump's output exactly matches the home's heat loss; below it, auxiliary heat makes up the difference. The economic balance point is where a backup fuel such as natural gas becomes cheaper per unit of heat than the heat pump, which depends on electricity and fuel prices and the heat pump's COP. Dual-fuel systems use it as their switchover temperature.
Why it matters in an audit
A tighter, better-insulated house has a lower thermal balance point, so the heat pump carries more of the winter, one reason audits pair envelope work with heat pumps.