As ever more people become interested in installing Air Source Heat Pumps, one of the continuing anxieties is around the size of heat pump required.

In this video I explain that a simple rule of thumb can give an answer within about 10% based just on the previous year's gas usage (in kWh).

The rule?

Heat Pump Size (in kW) = [Annual Gas Usage (in kWh)]/ 2900

This applies to the UK south of Manchester. It's very simple and in the video I explain how it works.

You can download the Powerpoint slides and get more information about degree days from my blog at:

https://protonsforbreakfast.wordpress...