Heat pumps vs Gas Boiler8 Jun 2024 20:08
Much to my wife's dismay, due to me looking at NG's recent comments about Heat pumps being the future, and their move away from Gas to Electricity, I decided to take another look at heat pumps. We have had a heat pump at our previous house and we weren't particularly impressed.
A good efficiency (COP) for a heat pump is around 4 in mild weather, but that can drop to around 2.5 at 0 degrees C; Heat Geek say they can get a COP over 4, but I'd guess much will depend on various factors, for example coastal temperature's will be milder than somewhere like the Pennines, or Lake District, and the current Central Heating pipework may also affect efficiency if it isn't replaced. My house uses 10mm Microbore, so unless I was willing to go through the disruption of having new pipework throughout the house, which I'm not, I'm limited on the size of radiators I can upgrade to; Basically the larger the radiators, the lower the flow temperature required and the more efficient the Heat Pump.
Currently the capped unit price of Gas is 4 times cheaper than Electricity, so basically a Heat Pump COP of less than 4 will be more expensive to run than a Gas boiler, with both on the capped standard variable rate tariffs. One of the reasons I'm considering a Heat Pump is that my current house is now 14 years old and British Gas inform me that the boiler is reaching end of life, due to lack of parts, and my wife would like to change various radiators with something a bit more cosmetic, like uprights in some of the rooms. I think all my current radiators are too small for a heat pump, apart from the heated towel radiators in the bathroom and ensuit's, and the even though the current cylinder is unvented it would also need replacing as part of a change to a Heat Pump system. I think my current central heating system is quite well suited to a heat pump upgrade, the Gas Boiler is in a cupboard in the kitchen right next to the wall and the space on the other side of the wall is probably where I would have sited the heat pump anyway, so they could rip out the boiler and hook into the existing pipework without tearing into the fabric of the house, I'm possibly the exception rather than the rule on that.
This video talking about various tariff's is interesting, but bear in mind that Heat Geek have a vested interest in promoting Heat Pumps and their most efficient installations will likely be the exception, rather than the rule, without significant changes to an existing household central heating system as part of any upgrade.
https://www.youtube.com/watch?v=c88Wv1HSlXs
There's a Β£7,500 Government grant for new Heat Pump installations, but it's likely a new cylinder and rads, plus installation costs, will take the price above that. I'm undecided if I'll upgrade to a heat pump in the future, much will depend on the price of Gas vs Electricity and other factors. I'd be interested to read other peoples opinions on this?