Most Victorian and Edwardian houses in London would have had gas piped to them from the day they were built as gas was often used for lighting, which is why when refurbishing period houses you may find a capped gas ‘nipple’ poking out of the walls around eye height where there would have been gas lights fitted. This legacy use of gas means there is infrastructure in our roads and has contributed to gas boilers becoming the norm in most of our homes. The infrastructure over the decades has been updated to ensure it’s safe to today’s standards with old pipes lined with plastic.
Its logical when refurbishing to review how you heat your home, especially given the focus now on climate change and it’s also natural to want to make sure you are future-proofing the work you have done. Which brings us to the question: “Can and should you get a heat pump installed now instead of a traditional boiler?” In offering our view on this question we won’t go into what a heat pump is and how it works as there are plenty of articles out there that cover that.
Passivhaus standard buildings with underfloor heating throughout are a good example of how heat pumps can work well. They operate at lower than the normal temperature of a traditional gas fired heating system with radiators. However, in the multitude of period properties across London it is very hard to achieve the same required levels of insulation and airtightness for these lower operating temperature heat pumps to work. As a result, there are now increasingly more heat pumps coming to the market that are able to deliver higher flow temperatures, closer to those of gas boilers. This is something we welcome as the environmental benefits to heat pumps are clear, particularly in the longer term if their compressors can be run on electricity that is made from renewables. But there are still a host of other issues to consider: even with the government subsidies available heat pumps are still more expensive to install than a gas boiler, and there is a shortage of people who are trained to install and maintain them. In London there are logistical problems too: the heat pump needs to be outside, so where do you put it and will you require planning permission to do so?
To be clear, we are big fans of heat pumps. But we’re not wedded to them; in our opinion in their current state of development they aren’t right for a lot of situations. So, what’s a realistic alternative?
There is talk of boilers running on hydrogen in the future. Now that’s a really exciting concept! Hydrogen doesn’t give off carbon dioxide when burned and there’s the potential in the future that it could be produced in bulk in sustainable ways. This is in addition to possibly of utilising the existing gas infrastructure that already runs to most houses. Our opinion is that the government, energy and boiler companies will push the development of hydrogen burning boilers along. One day there could be a switch over from natural gas to hydrogen, with boilers installed in the lead up to this with either the ability to burn both, or to have an internal element swapped over quickly and easily when the change occurs.
We think this will take some time to come about and so in the meantime the advances in heat pump technology are very interesting to keep an eye on.