Air source heat pumps: are they right for me? Interview

Heat pumps: an interview between members

This interview is great for beginners looking to learn more about heat pumps.

I: I’ve read quite a lot about various Heat Pumps being used instead of traditional heating systems. What made you look at these in the first place and how did you discover what you needed for your home?

a: I have always embraced technology and focused on ways to reduce my carbon emissions. This meant solar PV panels, smart heating controls, electric vehicles (EVs) for transport, using renewable energy suppliers and offsetting where possible. 

Faced with an opportunity to replace an ageing gas boiler I looked at the options available and after reading about Air-Source-Heat-Pump (ASHP) I was keen to take advantage of the innovative technology to heat my home with no gas fuel and use electricity from renewable sources.

The heat pump did require a change in the mindset and use to ensure that proposed benefits can be achieved in addition to understanding how the new heating system actually works in a real environment with cold snaps and seasonal changes. It has been a huge learning curve with realistic commercial benefits however significantly reducing the use of fossil fuel to heat our home.

I: Did you find it easy to find any real-world information you wanted prior to committing and did you have a reasonable choice of installers available? I usually look for guidance from existing users but with something like this I guess there weren’t many you could reach out to.

a: There was limited real-world information on using ASHP available except for some videos from manufacturers or commercial installations including ground source heat pumps. The insight on efficiency in a typical UK household with seasonal variation, insulation impact and switch from gas to electricity was/is limited.

The biggest input was the household energy survey report completed before the decision on installation could be taken. It provided a custom, relevant and indicative energy profile before and after the installation. The installer in my case was recommended by the survey company and turned out to be very competent and professional.

b: I am fortunate to work in the development industry and have been involved in a number of projects where developers were challenged on green heating, so started talking to colleagues on the energy side and then reading up and watching YouTube videos in my spare time. I even started to look into the RHI scheme and did maths into how I could make this work in my house.

I did go on an online forum and got a lot of good knowledge from experts who has web pages. Facebook forums were more difficult to navigate as there are some rather unpleasant “experts” on there….

Lo and behold the OVO trial came up so I gave it a punt (the rest is history). But I must say the knowledge I built up before the installation did help me in discussions with our installers, so very good value and time investment.

I also did my homework on our installer and questioned their technical expert as well as a phone call to Daikin tech help line. This was all around microbore piping in my home, which I was satisfied shouldn’t be a massive issue, and so far it hasn’t been as I am extremely happy with my system performance.

I: Is there one major piece of information looking back that was vital in your choice or critical in getting the information you needed to take the decision to go ahead with the project? Was there much to getting any grant or help in installing?

a: My discussions with the survey team and installers provided me with confidence however the location of the storage tank remained an issue till very late in the process.

It was quite disruptive to the existing kitchen which was identified as the only suitable place for the installation.

The grant was certainly the deciding factor. Even with the additional costs for self-funding in excess of the grant the installation in our case made sense as we had to replace our gas boiler anyway.

The process was long drawn between the survey, resolving technical and commercial issues, arranging the installation dates and then commissioning fully. A process which can certainly be improved with proper communication and engagement. 

b: Looking back I think it was the discussions with the installer and Daikin professionals that gave me the assurance to move forward. Re information, in my case I found an online article about pipe flow rates that give me comfort that my short microbore runs wouldn’t be an issue.

I: Ok, that’s really good to know. 

What about information on controlling the system? I’ve heard that controls and settings are rather different to a standard boiler. 

a: Yes, that’s where I think a lot depends on the installation. Almost all heat pumps have a wall control panel which can be integrated into the existing smart controls you might have in place.

The duration and temperature level, weather compensation curve, offset temperature, flow rate and cycle time settings will have a material impact on the energy consumption and heat produced. It requires a competent and customised setting by the installer with ownership passed on to the user to maximise the benefit.

In my case that has been an area of concern as settings are/remain an issue with excess heating bills and limited heating. The ideal coefficient of performance (COP) of the ASHP is rather hard to achieve however compared to a gas boiler should be achievable.

I:  What about ongoing support? Is your original installer still in the business and are they helpful or do they want to move on to other customers? I was wondering about servicing too. Is that similar in being an annual recommendation?

b: Our original installer is still in business and has serviced the system once since installation, next due in May. I am really happy with their service and during the last service made some useful changes to the setup which has saved us energy and money.

I: That’s all really useful, thank you. 

Finally from me has the system lived up to expectations and could you give three bullet points which you would tell others to make sure they look for?

a: I would say it has been a balanced experience with outcome (achieved) to eliminate the gas consumption from our house, however a learning experience to adjust to the new type of heating system. A few things I would encourage for anyone looking into getting ASHP:

1. Choose a professional and experienced installer firm and
2. Performance linked arrangement (i.e. COP) prior to installation to ensure the required calibration is performed and efficiency monitored.
3. Understand and accept that cost savings may be limited and lot will depend on how the system is used.

Hope this helps.

Here’s the second half of this, a recording of heat pump cost analysis, a must watch: