Although an important part of the government's climate protection targets is to facilitate the mass adoption of heat pumps, Bosch warns that the appliance is unsuitable for many homes.

In the United Kingdom, heat pumps do not make sense for older homes that lack extensive insulation or are not detached, Vonjy Rajakoba, managing director of Bosch UK warns. Bosch makes both heat pumps and gas boilers for the UK market under its Worcester brand and is one of the country’s biggest suppliers of central heating, selling tens of thousands of units each year. Mr Rajakoba said,

“At low temperatures you need well insulated homes, you also need space for heat pumps, for the external unit and also the tank, so you need to have the sort of home which is adequate around the heat pumps. Almost two-fifths of private homes, however, were built before 1945, according to government figures, that is, they are unfit for the installation and operation of heat pumps.”

Mass adoption of heat pumps is a key plank of Britain’s plan to reach “net zero” carbon emissions by 2050. The government wants to see 600,000 heat pumps installed each year by 2028, compared to around 35,000 today. However, adoption has been slow so far, owing to the high cost of installing them and concerns about their suitability for certain homes.

Purchasing and installing a heat pump typically costs between 7,000 and 13,000 pounds, according to the Energy Saving Trust. By comparison, a new gas boiler costs just 570 plus installation costs, The Eco Experts website writes.

Hydrogen boilers rather than heat pumps would be the solution for older houses and flats, but a parliamentary committee believes that it is not economically worth investing in hydrogen for the time being, Vonjy Rajakoba explained. Like Bosch, gas industry leaders are promoting hydrogen as a long-term solution for heating homes.

As V4NA reported earlier, it is not only in the UK that concerns about heat pumps are growing. A study has shown that less than half of the residential buildings in Germany are suitable for efficient operation of such appliances. Heat pumps can be installed in unsuitable buildings, but the inhabitants would be worse off financially than with the current system.

The efficiency of an air-source heat pump in an old building with an energy efficiency classification of „H” is 36 per cent lower than that of a heat pump in a building with a classification of „A++”. This has significant financial consequences:

The annual cost of gas heating in an uninsulated class H house was around 4,520 euros, a study found. At the same time, to run an alternative heating system, residents would have to spend around 5,900 euros, or 33 per cent more.

Yet the federal government wants to force the fitting of heat pumps in newly built homes and the replacement of existing gas and oil heating systems with heat pumps in other households. It has also been shown that careless installation of heat pumps in inappropriate buildings not only leads to high running costs, but also overloads the electricity network and thus the environment. In addition, many appliances contain gases that are highly carcinogenic, so even a small leak could be life-threatening.