Heat pumps debunked: 18 myths about heating debunked
- FALSE: ‘Heat pumps don't work in existing buildings.’ In a recent survey in the UK, 20% of respondents said they believed that heat pumps only work in newer homes. In 2023, the Daily Telegraph even published an article with the headline: “Heat pumps won’t work in old homes, warns Bosch.”In reality, millions of buildings of all ages have been fitted with heat pumps around the world. In fact, the UK government’s boiler upgrade scheme, which offers grants to households replacing boilers with heat pumps, only funds work in existing homes.After conducting several case studies of old homes with “air-source” heat pumps – those that draw energy from the outside air – public body Historic England concluded in a report last year that these “work well in a range of different historic building types and uses”.The UK government-funded “electrification of heat” project took this a step further, stating that “there is no property type or architectural era that is unsuitable for a heat pump”.Results from the project also indicate that there is no significant variation in performance based on house age.These findings are not exclusive to the UK. Research organisation the Fraunhofer Institute in Germany carried out extensive field testing and monitoring of heat pumps in existing buildings and concluded that they worked reliably and without problems.
- FALSE: ‘Heat pumps only work in highly insulated buildings.’ A common – but false – claim is that heat pumps require extremely well insulated buildings to perform properly. For example, Mattie Brignal, senior money reporter at the Daily Telegraph, wrote in October 2023 that good insulation was “crucial” for heat pumps to work:“Effective insulation is crucial for heat pumps to function optimally because the devices operate at lower temperatures than gas boilers.”“Heat pumps will never work in Britain,” he claimed, partly because of the UK’s poorly insulated housing. It is indeed true that the UK has one of the worst housing stocks in Europe when it comes to insulation, as data from smart thermostat company tado shows.Heat pumps can work in any building if sized, designed and installed correctly. Many uninsulated homes and buildings are already heated to comfortable temperatures with heat pumps, as shown across multiple case studies, including an uninsulated stone church.
- FALSE: ‘Heat pumps only work with underfloor heating.’ In a recent survey commissioned by the energy supplier Good Energy, 15% of respondents said they believed heat pumps would require underfloor heating.This is incorrect. Heat pumps work very well with radiators, too, though the lower flow temperature required by underfloor heating means this radiant heating can make heat pumps work more efficiently.In some cases, the radiators may need upgrading. However, it has been common practice in recent years for heating installers to oversize radiators to apply large safety margins for providing sufficient heat.If insulation is installed at a later date, the original radiators will also be larger than required. Some radiators may, therefore, need to be replaced to install a heat pump, but this will depend on the property.Plenty of properties listed on open-source platform Heat Pump Monitor, which allows individuals to upload key information about their own installations, have heat pumps and old radiators, but no underfloor heating.
- FALSE: ‘Heat pumps won’t work in flats.’ The Daily Telegraph reported in October 2023 that “many flats are unsuitable for heat pumps”.Similarly, in August 2023, the Daily Mail reported the comments of Climate Change Committee chief executive Chris Stark saying it is “>very difficult” to install heat pumps in flats.Finding space for the outside units of air-source heat pumps can indeed be a challenge, when it comes to multi-apartment buildings. Solutions for this problem exist, however, as documented in case studies of blocks of flats using a variety of heat pump technologies including ground, air