A mid terrace heat pump example (COP: 3.92)

A case study of an air source heat pump in our mid-terraced house. Including monitoring results and how we achieved a COP of 3.92 over the first year!

Updated blog post on heat pump performance for 2020 (includes monthly data)

Blog on heat pump performance 2019

John Cantor’s website (with link to his book)

Carbon Coop Webinar: Retrofitting Domestic Heat Pumps
methods and lessons from Ireland with Paul Kenny of Tipperary

MCS Heat Pump installer standards and tools

MCS Heat Pump Calculator v1.9

Web tool (In development) see:

Useful YouTube videos by John Cantor:

Heating old buildings with heat pumps:

Heat pump refrigerants:

Flow rates and pressure drops:

Heating simulator

A great video by my friend and colleague Glyn Hudson on installing his Samsung ASHP:

[jaminboy]

Thank you for the most useful information on air source heat pumps I have found. If only more YouTube videos were this good.

[zalkhirsan]

This is simply the best video I have seen on YouTube and I work in low carbon field

[maxflight]

Congratulations on your new arrival ! Being a father is amazing. Very best wishes.

[davidbowen]

Awesome stuff Trystan. This was exactly the sort of detailed information I was looking for before I bought my heatpump so hopefully it'll help others decide what to do.

[lookcreations]

Brilliant, first time I’ve seen some useful information and it relates to my old stone built cottage. Staggered at the cost of your system, it’s less than half what I’ve seen quoted. Thanks for uploading. All the best Mat

[georgeturner]

Great information! I’ve started with insulation and solar thermal. Now looking at heat pumps so glad I found this video. Thanks for posting.

[bruceboucher]

Trystan, more of this is what the public needs, I feel the space temperatures were low for the older generation, but all in all a great advert for the Heat Pump i common scenarios

[chriswass]

Many thanks for posting this informative and well presented video. We will be referring to this a lot in the coming months as we consider our own project.

[liammullan]

Thanks for taking the time to post this Trystan, very helpful

[justinrobinson]

Really useful information. Thanks for sharing your experience! I particularly like the image of the layout and associated cost of each part. It shows the simplicity of a ashp wet system (compared to what a wet system is made out to be). I would consider looking at a wet system now as previously put off by complexity and high installation cost.

I have an air to air system that I am really pleased with but imagine the spikes in energy will be more severe. I hope more people watch this and realise a retro fit of a full system is worth doing if done correctly!

[peterward]

Important information on heat pumps through your practical experience. So useful for me to make a decision on a GSHP. Thanks for the video.

[stevensalisbury]

The best energy efficiency video I have watched, I was looking at LPG and wood burners, this has been the most useful information I have found, most of us would like the ground source heat pump just a bit out of the price range.

[johncantor]

Great video Trystan. I just wanted to flag up one small point. If anyone were trying to reduce the working water temperatures using a fan radiator... beware! Fan rads don't like lukewarm water. This is because blowing slightly warm air can feel to us like cold air. Comfort at the lower end of temperature spectrum (say 19-20C) tends to go with low air movement. Fan rads have a fairly crude fan cut-out inside them. Fan stops if water not warm enough

[danielvivian]

Trystan, thanks very much for the detailed description and analysis of your system. I'm a mechanical engineer who concentrates on building energy conservation and sustainability. I live in Ottawa Ontario Canada and note many significant differences between our locations. Probably the largest is the temperatures. Our average January temperatures are high -6 C, low -14 C but the design temperature is -27 C (which is generally achieved for a few hours a year). Heat pumps typically work to about -20 C then the COPs drop so low (1.1) you need to use 100 % back up electric resistance heating (luckily there aren't many hours in the year at these low temperatures). Partial back up heating is typical from about -8 to -20 C. We seldomly use radiant heating in our houses. Mostly it's forced air (natural gas in the city and forced air propane, fuel oil or electric resistance in the country). Some use electric baseboard resistance heating. Natural gas heating costs about $ CAN .05/kWh here. Propane fuel and electric resistance is a very poor economic choice, about $.16/kWh verses $.08/kWh for heat pump on our electricity costs or about $.05/kWh when heat pumps and solar are combined. Sorry, I understand that the sun did shine in the UK once! November and December even most of January are quite cloudy here but February is generally bright. Surprisingly London (51 N) is north of Ottawa (45 N) so we would get more winter sun than you.

[chaswinder]

Really useful and informative write-up on your heat pump experience, thanks so much for making and sharing it.

[krnlg]

This is a very helpful video, thanks. I'm very impressed by the performance of this, as you said, relatively simple system. I have been wanting a heat pump system for a while but can't afford anything fancy. It is reassuring to see such good results without underfloor heating and in an otherwise unmodified house!

[briangriffiths]

Despite my reservations about ASHPs, I found this a very enjoyable and informative video. My thoughts are that once ASHPs are expanded to a wider audience and gas an electricity prices are equalised, the current MCS standards will be relaxed so that the heat-pump is not expected to cope with extreme winter loads and homeowners will rely on, say, a couple of 2kW space heaters as back-up in more modest homes up to about 100 square metres. I also believe there will be more innovative retrofitting to avoid the current excessive installation costs.

[DrumToTheBassWoop]

Thanks for the information dude, my elderly parents are moving house from a solid fuel fire heating, and I’m going to send this to them for a more alternative way of heating a home example.

[tommy]

Great video. Just trying to decide on a new heating system and this has definitely helped. Thank you.

[bruceboucher]

Hi Trystan, I hope the manufacturer of your Heat Pump Mitsubishi is giving it plenty of Air time (no pun), your post has done more for the Industry in recent times than most.