Air source heat pumps provide the right energy solution for these householders
It’s expected that half of Scotland’s energy will come from renewable sources by 2030. Change is happening right across the country and nearly 400 householders across the Highlands and Islands are among those leading the way. They are members of the 1,100-strong Green Homes Network in Scotland, which connects anyone thinking of installing renewables and other efficient new heating systems with people who have travelled that path already. We talked to two Green Homes Network members - Tim Johnston of Lentran near Inverness and Mathieson Ross of Aviemore - about their experience of using air source heat pumps and their reasons for installing them in their mid-20th century properties. Air source heat pumps extract heat from the outside air and convert it into useful energy which can be used to heat radiators, underfloor heating systems and provide hot water in your home. Why did you choose to install an Air Source Heat Pump (ASHP)? Tim: When we purchased the property the only energy source was electricity. We looked at our options and the air source heat pump seemed the best option environmentally and economically. Mathieson: We decided to install a heat pump due to the excessively high oil prices – the kick in the wallet was the biggest incentive to change our oil fired system to a renewable one. Is it simple to operate? T: Yes, once you have got used to the user interface and lived with the system for a few weeks, it is straightforward. M: Yes it’s as simple as any other central heating system – you just set the temperature and time of day as required. Is it easy to control the temperature in different parts of the house? T: The thermostat is placed in one room, in our case the kitchen, and once that room reaches the set temperature the pump will shut down. We have smart radiators in all the rooms so they can be adjusted to control individual room temperatures. M: An underfloor system would have different controls but we use thermostatic radiator valves on our system to control the heat in different rooms. Is it noisy? T: The unit is situated outside and it is much quieter than we anticipated. The smart radiators can be a little noisy when they are blowing out warm air but after a while you don’t really notice. M: It is much less noisy than an oil or gas boiler and doesn’t emit any fumes. How do the running costs compare to your previous heating system? T: We have never had another heating system so cannot compare. When we bought the property we had our system installed before we moved in. We also installed a wood burner in the lounge. M: Our fuel bills have halved since installing our air source heat pump. Does it heat your hot water? T: Yes, it has a programme for heating domestic hot water (DHW) and for disinfection to prevent Legionella. M: Yes. Does it work well in winter? T: We have had two winters with it so far and it has performed well with no problems. M: Yes - even in the very cold Aviemore winters. Our system has worked with an outside temperature of minus 23 °C. In very cold weather it will require more fuel but that would be true of any system. What advice would you give to someone considering ASHP? T: Look at all your options before making a decision. For a heat pump to work efficiently you need to have good all-round insulation as the less heat that’s lost from your home the more efficient the system. The initial outlay can seem quite expensive but we are getting around 50% of this back over seven years with the domestic Renewable Heat Incentive (RHI) payments, plus savings on our energy use. If you think an ASHP is your best option then I would say you should seriously consider it. M: Insulate your home first. I would also recommend installing solar panels with a power diverter which will heat your hot water in the summer and prolong the life of your heat pump. Do you have any other advice or information? T:
If you are thinking of installing an ASHP system make sure you get at least three quotes and also make sure you choose reputable companies who know what they are doing regarding installing heat pumps. It’s a good idea to ask around. M: Against the advice that they would not work in the cold Aviemore winters, we went ahead and fitted an ASHP and we’re really glad that we did. We now have less than half the fuel bill that we had before installing. Apart from the savings in fuel bills, the newly increased RHI for heat pumps should be more than enough incentive. It’s a green issue too, good for you and good for the planet – definitely a win-win. Tim lives in a detached property with insulated cavity walls and Mathieson’s is a semi-detached home with insulated cavity walls. Home Energy Scotland is a Scottish Government programme managed by the Energy Saving Trust. Its network of local advice centres covers all of Scotland and expert advisors offer free, impartial advice on energy saving, renewable energy, sustainable transport, waste prevention and more.