Air source heat pumps in winter: Busting the myth

  • Mailman's Avatar
    Level 57
    Who is paying now for solar, heat pumps and EV's? A subsidy is there on some of this but essentially its consumers are paying to make the change.

    People with deep pockets/savings in the main I would suggest.

    I upgraded my gas boiler in my previous house in 2019 at a cost of about £2000 with very little inconveniense to myself - very little additional piping, no changes to the rads and their attendant piping. Ironically none of it was microbore and was more suited to ASHP. Newer house now but has microbore all over the place so much of the flooring would need to be lifted for larger piping I suspect. Almost certainly some/many of the rads would need changing as well. New hot water tank would need to be installed with its attendant piping. Even with a £7500 uplifted gov grant, I suspect a new ASHP would cost me probably upwards of £5000 and possibly in excess of £7500. There are very few ASHP installers in the NE when I have looked but you can fall over the number CORGI registered gas boiler installers up here. On the estates where I live I have yet to see a single ASHP installation and yet I know I am better off than many many folk that live nearby. Even the 300 new houses being built nearby right now are being fitted with gas boilers! Annual gas cost for my usage is currently about £500 pa (on circa 5900kWh gas consumption). If I went back to my old usage patterns (and a cosier house) I'd be spending maybe £1000pa. Until the price of gas becomes more expensive (relative to electricity) than it currently is I'll not be going down the route of ASHP for all the reasons I've outlined for my circumstances.

    Solar on the other hand is something I might be more tempted to explore more thoroughly particularly as there appears to be a decent pay-back period and the installation experience is less intrusive. Given the choice of getting solar v ASHP then solar wins it for me ATM. I'll certainly be looking at this option during the next 12 months.

    EVs are still priced at a premium compared to petrol but being the age I am, I cannot see me driving past mid-70s (if I last that long) and I'm not sure I'd want to judging by the lunatics I see on the road these days. The days of driving long journeys for me all over the country are history and I currently do maybe 3500 miles pa. I'm sticking with my current 10 year old Polo for as long as I can and decide when I need to.

    If I had maybe £50K+ loose change in my pockets I'd do all three (ASHP, Solar, EV) and stay in a posh hotel for a couple of weeks 😄 but the reality for me is somewhat different 😥
  • meldrewreborn's Avatar
    Level 91
    @Mailman

    it isn’t a case of doing everything at once. When something needs replacing we work out what the best option is and do that. And wait for the next problem to arise. Sometimes the gods shine on us though. Mrs M had a 25 year old corsa from new, but it wasn’t ULEZ compliant and needed some work before its next MOT. So we’ve scrapped it under the TFL scrappage scheme. We’ve had partial refunds on VED and insurance, plus £300 for the vehicle and £2000 from TFL. Playing the long game worked for us😃
    Current Eon Next and EDF customer, ex Zog and Symbio. Don't think dual fuel saves money and don't like smart meters. Chronologically Gifted. If I offend let me know by private message, but I’ll continue to express my opinions nonetheless.
  • Mailman's Avatar
    Level 57
    @Mailman

    it isn’t a case of doing everything at once. When something needs replacing we work out what the best option is and do that. And wait for the next problem to arise.

    Wise words 👍 although some sections of society make out that somehow you are a lesser human being because you are not dressed in a hair shirt and living in a cave😄.
  • meldrewreborn's Avatar
    Level 91
    @WizzyWigg

    I think there's another myth here about heat pumps - that they don't work well in poorly insulated properties. Of course they will work well and just as well as a similarly specced gas boiler. The issue is that if a property needs to use a lot of gas, then it will also use a lot of electricity to do the same and electricity is 4-5 times the price of gas, before taking the variable Coefficient of Performance of the heat pump into account. A heat pump in a poorly insulated property will be very costly to run, just as a gas boiler would, but people conflate the factors and come up with factually incorrect statements.

    The cop of a heat pump is never guaranteed - but mainly due to the factors surrounding its installation and configuration and operation by the owner rather than issues with the heat pump itself.
  • WizzyWigg's Avatar
    Level 80
    @WizzyWigg

    I think there's another myth here about heat pumps - that they don't work well in poorly insulated properties. Of course they will work well and just as well as a similarly specced gas boiler. The issue is that if a property needs to use a lot of gas, then it will also use a lot of electricity to do the same and electricity is 4-5 times the price of gas, before taking the variable Coefficient of Performance of the heat pump into account. A heat pump in a poorly insulated property will be very costly to run, just as a gas boiler would, but people conflate the factors and come up with factually incorrect statements.

    The cop of a heat pump is never guaranteed - but mainly due to the factors surrounding its installation and configuration and operation by the owner rather than issues with the heat pump itself.
    👍 Are we not here to Bust the Myths and offer the facts? 🤔
  • wizzo227's Avatar
    Level 21
    Charts of CoP vs outside temperature (at collector air inlet) for several example lines such as 45C radiator temperature and 55C radiator temperature would be the proper way to demystify this question with facts instead of with peoples' assertions and opinions.

    For some reason those charts are as difficult to get as the sales reps can make them be. Please could someone have a go at obtaining proper charts from the test department of a few example heat pump suppliers? What form do they measure them in ? For example, my small single stage air-air heat pump uses a slightly-variable electricity between 0.6 and 0.8kW to deliver heat at a very outdoors-dependent rate of up to 2kW (also depending on history, coldness, sun in that corner of the garden +++), so the natural form of test charts would be one chart of electricity vs time, another one of heat output vs. time, a third chart of outdoor thermometer near to the collector, and a forth chart of indoor temperature vs. time. Too complicated for some people? That's not too complicated for me; just chart everything and print them all on one page and I'll be happy.

    Did you know that in the mild weather which we are having, some heat pumps can move heat from the garden at +15C with less electricity than in normal weather ? That is what mine does but it is single stage air-air.
    Last edited by wizzo227; 03-10-23 at 17:49. Reason: spelling "form"
  • Mailman's Avatar
    Level 57
    @Mailman

    You mean to tell me that you don't?

    Actually I do follow your doctine re replacement and working out what is best for my situation at the time 😁 - selfish I know but my pockets are limited. 😥
  • meldrewreborn's Avatar
    Level 91
    @Mailman

    I think it’s an entirely rational way to approach things. While there are people who place environmental concerns above all others, they may find that it exhausts their financial capacity and then are unable to take other steps towards saving the planet.

    I read recently that mean sea levels at the end of the last ice age, so less than 10,000 years ago, were 120 metres below those of today. It does make you wonder whether the policies of King Canute are still alive today.
  • wizzo227's Avatar
    Level 21
    Previously I claimed that my small air-air heat pump does not use much power in mild weather. Today I tested, switching it on for a change. Several hours later the living room is toasty hot and it used a grand total of .................................................. .................................................. ................... 0.5 kWh
    That's right; not a lot of power used at all this afternoon. The outlet for heat in the living room is pictured. I can't tell the difference between the outward appearance of this and an air conditioner.
    This air-air small heat pump being standalone, it does not do hot water. Tonight is bath night so I will run the 23 year old gas combi boiler for 6 minutes using up to 2kWh of gas for that bath. I challenge anyone to measure truthfully better comparison figures.
    Name:  heat_pump_blower_02107.jpg
Views: 292
Size:  40.5 KB