Ed’s Blog: Air Source Heat Pumps


Ed, is a pilot and has recently bought a Victorian property with his wife just south of Reading. He is quite conscious about the environment and his carbon footprint, but due to his job, he appreciates his carbon footprint is not where he would like it to be.

Over the next few months, he will be writing a regular blog for us, sharing the steps he is taking to make his home more energy efficient and his life more environmentally sustainable. 

Ed's BlogEd’s Blog: Air Source Heat Pumps

Christmas maybe over, but with more cold snaps being forecast, it looks like winter is stretching out for a few months yet! Typical for January, everyone appears busy adhering to their new year’s resolutions and I am no different. Two of my resolutions for this year are to reduce my carbon footprint and to get a better hold on my personal finances!

I’ve heard lots about air source heat pumps (ASHP), and I was wondering if they would work on my property. So earlier this week I talked to an installation company about the prospect of installing an ASHP in my home and through this blog I am reporting back on what I found.

ASHPs are a brilliant way of extracting heat in air particles to warm buildings. They basically work like a refrigerator in reverse. In a fridge, you remove the heat from the air inside it, making the interior cool. This is why the pipes on the back of the fridge heat up, because they channel the heat to the outside. Air source heat pumps take heat from the air outside your home and channel it into a building, therefore warming it up.

Planning permission for heat pumps

So, I had this very lengthy conversation with the ASHP engineer and this is what he told me:

    • Firstly there is no need to get any sort of planning permission for an air source heat pump if you live in England; ASHPs are considered a permitted development.
    • The ASHP does however need to be situated at least a metre from the edge of the boundary of your property and it must also be in a place that doesn’t impact the external appearance of the building. (I think what he meant was that it would be better to place it on the side or round the back of the property, which would not affect the view of the house from the street).
    • You just need an outside wall, so they can be installed on almost all properties; detached, semi-detached, terraced, bungalows and even flats.
    • The pump itself isn’t very big. The one the engineer showed me measured about 3 ft high, 4 ft wide and just was less than 2ft deep, which according to him was sizeable enough to source my property.

The conversation got very technical and I was worried I would have to make additional investment such as installing new plumbing to be able to cope with this new system (understandably was getting concerned about the potential cost at this stage!). However those fears were allayed when I found out that the ASHPs can be fed into the current central heating system without much additional cost and effort.

In addition, I would say if you have a bit more to spend and are looking to upgrade your property throughout, ASHPs can also be used to heat water, both for use or to supply your new underfloor heating system.

The engineer also recommended that in parallel I ensure that I have the best possible insulation in my property, because ASHPs work best when they have this in place. Luckily, my property is pretty well insulated, and this was one of the attributes that I looked for before I decided to buy.

Cost of an Air Source Heat Pump

So the important figures for me are and what you will be interested in too is, ‘how much I money would I actually be saving’. He said: I would be looking to spend around £6,500 for the system, which would save me about £650/year. So in ten years it would have paid back. Further down the field, having a microgeneration system attached to a property is also a good selling point as I would expect that this feature would increase its market value.

The savings bit (above) covered off my personal finances checkbox and the other half of my resolution was also covered – installing an ASHP system would also reduce my carbon emissions by 5,400kg/year!

I’d like to add, the other advantage I have in the property is that I have electric heaters installed. This property feature according to the engineer would benefit more from an ASHP, than someone supplied with mains gas, because it would be cheaper to run.

Ensure MCS Accreditation of your Air Source Heat Pump

The good news is that if you buy your pump from a certified MCS installer it comes with a ten year warranty. ASHPs are relatively maintenance free, though the engineer did recommend having them serviced every three years or so. Some of the general maintenance I am confident I could do myself such as: making sure there is no growth near it; ensure inlets are free of debris and ensure there is a good airflow going into the system. I even reckon it would be quite easy to check the levels of antifreeze myself if someone showed me how to do it.

Make money via the renewable heat incentive!

A little further down the line (late 2013), there is also the government’s Renewable Heat Incentive (RHI) to think about. The RHI, when it comes in later this year would offer me between 6.9 and 11.5p for each kWh of heat energy that I produce. It’s hard to know exactly how much that would save me, but it’s got to be worth a few extra quid over the next few years.

So, all in all, I’m going to go for it. I’m lucky that I’ve got the right property with the right insulation levels, serviced by a relatively modern system, which will complement the heat pump. I’ll blog some more once it’s installed (end of February) and let you know how it’s going.

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