Air Source Heat Pumps - viewer questions answered, efficient running and costs 

Nice thorough explanation of some of the finer points of the installation that most people would never understand.

This adds a whole new level to heating - not simply adjusting the thermostat. But looking at predicted weather and making adjustments

Very interesting, thank you from a Dutch viewer. I have the same problems with my Daikin heat pump.

21deg. Just wondering why you need such a high temperature. In our house 18c is hot. Also, you have radiators under windows with curtains hanging over them, I would relocate the rads, or extend the window call boards and cut the curtains above.

The margins between an oil fired central heating system and an air sourced heat pump at the moment seem to be small and constantly moving. Given that the savings/year will not be vast I would suggest that a changeover of heating system should only be considered at a point where a replacement of an oil boiler has become essential. Like cars one of the biggest costs of heating systems is that of depreciation. Unlike a car the value of a secondhand oil boiler is minimal as the cost of installation probably means that most people would rather buy new than take the chance of installing a secondhand boiler. This means that there is no or very little offset against the cost when purchasing a replacement heating system. Therefore it is probably a waste of money at the moment to change ahead of the end of life of the boiler. If a an oil boiler is about 90% efficient and the price is 90p/litre, as the heat energy in one litre of oil is about 10kwh, electricity would need to be below 8.1p/kwh for conventional electricity heating. For a COP of 4 this would become about 32p/unit which is much more achievable. Given the present fluctuations in the energy market I guess it will be at least a couple of years before we can make meaningful decisions on our choices of heat energy from an economic point of view. Certainly even if we just break even the air sourced heat pump would be a good choice from an environmental point of view.

Very interesting thanks for sharing

Thank you for sharing. Brilliant information

wait, isnt that the house Artisan Electrics rewired some months ago?

Currently I'm paying 24.7p per kwh for electricity and 10.4p per kwh for gas; my 35 year old boiler is 80% efficient so in effect I pay 13p per kwh to heat my house with gas. I think in future gas will increase in price faster than electricity as green levies are placed on fossil fuels. 2 years ago I had rooftop solar and a powerwall installed which generates about 5500kwh per year, I currently export about half of that amount to the grid. Next year I plan to get an ASHP (probably a Vaillant) and hope it will be able to get a SCOP of around 3.5. My excess solar should go a long way to cover the cost of running the heat pump. I would definitely recommend solar and a battery to anyone with a heat pump.

Informative video and although a bit technical I could see how you approach your own situation. We have 3 ASHP's in our bungalow and have them set to go no higher than 18c ,we rely on these units as our boiler and rads are now decommissioned and scheduled to be fully removed next year. We're looking at solar and battery tech for our next project. A question on your ASHP's, why are they positioned in your garden area instead of fixed to the main house ? Is it due to your house being of a certain age ? Peter

Electric cost is linked to gas costs which are similar to oil. So they should in theory both change together. Of course as more renewables come into the equation, electric will be more stable, and we hope less. So ASHP should make economic sense in time.

@ Modern Thatch Living. Firstly, thank you very much for such an informative video; there are very few posts with this level of analysis, so I really appreciate your effort. The question I have relates to your "Example calculated flow temperatures for our system..." graph, with time stamp 8:39: are you showing return flow temperatures (for example 29 degrees at 0 degrees outside) or heat pump-generated input temperatures into the manifold? Many thanks.

All this should have setup in the design.

How does this work for a air handler system and not radiators? If a system is rated for a COP is that at a certain temperature?

If you got a large battery and charger it at 12p. Then run the heat pump off that

Thanks for the explanation. Was the clip of the defrosting in real time?

Are you making dhw with your ashp? Thank you John.

As a solar installer, I can only share that the sooner you install PV the quicker the payback. My advice would be to avoid Chinese brands and stick to well reputed panel manufacturers like Sharp, Hyundai, Solarwatt, REC, ALEO or Panasonic and Inverter brands like Enphase or SolarEdge. If a battery is on the cards, I'd suggest Tesla or a MyEnergi Libbi as the most future proof solutions.

I didn't quite catch the name of the fan unit in the room with the wood burner in. Could you provide a link in the description please.

Just received an £3500 quote for a new oil tank installation as it needs moving and replacing due to regulatory changes. Team that with an 20 year old boiler, I'd be in for at least £10k.. So been looking at ASHP for a while, main benefits I don't have a commodity in my garden which could be stolen, yes electric is expensive but when crunching numbers over filling my oil tank, having it replaced, running the heating etc then ASHP is a no brainer. Just spend some time draught proofing your home if it's old like mine.

very nice job with the video. I would ask if you have considered the cost of professionally cleaning the heat pumps because that will greatly affect your COP. Also, do you have a budget for service when the need arrises?

I agree, BRILLIANT Happy for you.. But , let's get it right.. Only those with enough excess CASH can live this life. YES IT CAN WORK but only after huge fiscal input. All of the videos feature the same people. Nothing wrong with these people, good people. But the up front cost is huge .

Solar, of course you won’t get much benefit when you really need it. Although if you have an EV that is different. Perhaps putting some investment in a community wind farm makes more sense, if only on a green agenda. Ps, good revue, though I have to admit putting you on 1.25x speed, no criticism, you are just a happy relaxed guy.

Interesting video for sure. If you were very happy with saving 10 quid a day by tweaking your heat pump temperatures then your electricity bill must be absolutely monumental?? It seems a common theme with honest heat pump videos like yours is that if you do not own a solar system - it's no cheaper than oil a lot of the time - especially if you factor in the fact that your existing oil system is working fine, it doesn't make sense to me to then go spend £10k on heat pumps just to save a few quid here and there in bills? Lots of people seem to be doing just that nowadays! Get as much solar as you can fit ASAP and watch your bills drop like a stone.