Heat Pumps

10 things to know about heat pump sizing

Published 1 Jul 2026

What this video covers

Getting the kW right, counted down to what matters most.

Ten things to know about sizing a heat pump, counted down to the one that matters most. Get this right and everything else follows. From Axiom Eco Homes.

In this video

  1. 0:00 Intro
  2. 0:10 10. It's about heat loss, not floor area
  3. 0:27 9. Most homes need 4 to 12 kilowatts
  4. 0:44 8. It's sized for the coldest day
  5. 1:01 7. Bigger is not better
  6. 1:19 6. Too small and it can't keep up
  7. 1:35 5. Radiators are part of the sizing
  8. 1:52 4. You may need a buffer or volumiser
  9. 2:07 3. Hot water adds to the sizing
  10. 2:24 2. Insulate to shrink the size you need
  11. 2:39 1. Insist on a proper heat-loss survey
  12. 2:57 Where to start