Everything you wanted to know about heat pumps but were afraid to ask
Much of the difficulty people have trying to understand heat pumps is that too often the discussions are very much between experts who already understand them, using lots of the jargon. Little effort is put into explaining basic concepts like 'efficiency' that the layperson is only vaguely familiar with.
Also, there is a lack of appreciation of just how ubiquitous heat pumps are in our daily lives, and some who try to frame air-source heat pumps as some new fangled unproven technology really do not understand their history.
So when 'Wotton Area Climate Action Network (CAN)' asked Dr Richard Erskine, our Education Lead, to do a talk on heat pumps he started with a fresh canvas, working very hard to make the talk accessible.
The talk starts very broadly, looking at the history of heating (wood, coal, gas, electrification) and the history of heat pumps, starting in the 1830s.
It then demystifies what heat is, and how heat pumps work, with analogies from everyday life that are familiar to people, using some props to help explain things.
It then goes into practicalities, and explains why heat pump efficiency is so good it even trumps the UK's terrible 'spark gap' (electricity unit price to gas unit price ratio).
The talk aims to help owner-occupiers, but goes further, to consider different settings, such as social housing, community spaces, churches, etc., and the emergence of 'heat as a service'.
The mantra ‘fabric first’ (meaning insulation, windows, etc.) is discussed and challenged with the help of insights from NESTA.
The talk discusses the Heat Geek proposition 'Zero Disrupt' and tries to put it into context (lower installation costs versus lower running costs)
Finally, the talk looks into the future, where we have a fully electrified economy, with a smart grid, smart homes and flexibility in the system, powered mostly by free energy from the sun. This will bring many benefits including energy independence, and resilience. Heat pumps will be a key part of that future, in heating our homes and in industry.
Richard concludes by imagining 500 years hence, and what historians might think of us. They will see the poisoned chalice that the fossil fuel era brought us - ‘The Great Derangement’ in Amitav Ghosh’s word - with consequences that will be with us for millenia.
We still have time to mitigate the worst outcomes, but we need to act with urgency and focus.
A video of the talk (filmed and edited by Christina Wheeler) is available via the WottonAreaCAN website, and direct YouTube link here (Talk approx 40 mins, Q&A approx 30 mins)
Richard gave a second outing of this talk on home turf on 1st Dec. 2025 for NailsworthCAN, at Sawyer Hall - with slightly updated slides. Despite terrible weather there was a good turnout. . The talk included references to changes to ECO and BUS grants, following the budget. The PDF of those slides is available:
In the slides there are numerous links, including a 'Getting a heat pump checklist' Richard has created to complement the talk https://www.nailsworthcan.org/getting-a-heat-pump-checklist