How do I know my house will be warm with a heat pump?

This is the common cry from homeowners making the switch. It’s a new technology to most of us, so how can we know what we’re looking for? Ideally, you’ll take a bit of time to understand how heat pumps work and what you need from an installer. Here’s some thoughts to get you going.

Installers

It’s a challenge to find a heat pump installer who is really good at their job. The most important part of the process is the heat loss calculation they make at the beginning. This is an room-by-room heat loss calculation to determine what size pump will provide the required warmth at a relatively low flow temperature and high efficiency. The more accurate the provider can be with this, the better the outcome for the homeowner.

 Heat pumps work best when left to do their own thing. So you want an installer who is confident in their heat loss calculation, so they’re not tempted to:

·      put in a bigger pump ‘in case’ you’re not warm enough

·      add a buffer tank to increase water flow in case you’re not warm enough

·      include thermostats to regulate temperature, in case you’re cold and want to turn the heat up

While the intention is good, all these factors risk interfering with the heat pump, making it less efficient. When the system is simple and uncomplicated, the pump can just get on without having to fight different instructions from thermostats and buffers.

When the pump is larger than necessary, it has to turn on and off more often in order to maintain a consistent heat. And that uses a lot more in energy than it should.

How to sort the experienced from the newbies

Take time to look for a good installer who really knows their stuff. One way to do this is to look at Heat Geek on YouTube – they have loads of information that can help you understand the process. They also have trained Heat Geeks across the country.

When you are visited by a potential installer, ask questions about:

·      Weather compensation  - this ensures the pump adjusts to the outside temperature and provides the energy you need to maintain your ideal temperature. And, when switched on, it means you don’t need internal thermostats.

·      Temperature to set the pump at – usually this would be between 35 and 45 degrees (lower than a gas boiler that runs at 65). Find out what temperature they suggest and why

·      The temperature of the water – approx. 45 degrees. You don’t need it too hot. Remember most of us add in cold water for a shower or to wash hands. So having the temperature too hot is a waste of energy

·      How long it will take for the house to warm up once the pump is commissioned. Because it runs at a low temperature, it takes longer for the home to become warm enough.

·      Whether they are suggesting a buffer tank and why. This may be a sign they’re not sure of their calculations or it may be to manage extreme cold when the fans of the pump might freeze up. If the installer is up to date with the latest tech, they’ll know that a particular valve can be added to the pump to manage this, so a buffer is not needed.

Take your time and take advice

This is a relatively new arena in UK, so many installers are still learning. Some have made the switch from installing gas boilers without fully understanding the basic difference. Heat pumps work very differently and until all installers get hold of that, homeowners need to be informed when choosing how to give the work to. 

·      Talk to anyone you know who has already installed a heat pump

·      Visit a home with a heat pump so you can feel the quality of the heat and hear about their experience. You can do this by going to Visit a Heat Pump.

·      Take a look at local Facebook pages – there will probably be one for renovations. Also Heat pumps UK and Ireland gives a lot of information

·      Go exploring on YouTube to understand more about the process. 

·      Get more than one estimate of cost and timing.

Trust in the building profession overall is low just now, but a new area like this can be particularly

daunting. Search around and see who you can find – there are now companies that have both male and female installers which can sometimes make a difference.

Loads more about heat pumps in What the Builder Won't Tell You Order on Amazon or good bookshops.