For us, May and June have not been what we could call warm or summery. Frankly, the weather has been cold, wet and miserable. Typically, on last year’s tariffs, our central heating would still be on, but with the price of electricity at the moment (and for the foreseeable future) our heating been off since late April.
The house not been uncomfortable. We’re used to temperatures in living areas of around 21-22C. With the heating off, the southern part of the house maintains around 20C, and the northern part (where our TV room is) drops to 18-19C on overcast days, which does feel very cool.
But we’ve decided to suck it up. The heating has stayed off to save money and the air source heat pump is now only heating our hot water – to an efficient 44C. On days with little or no solar gain, we’re layering up with an extra sweat shirt or jumper, and an extra blanket has gone on the bed.
On really cold days, like the Sunday of the Queen’s Jubilee, where we never exceeded 9C, we put on a small fire on in the kitchen/diner and watched TV there in the evening.
Generally speaking, we’ve been pleased with the way the house has held out at these lower temperatures with no heating and that’s in no small part to our efforts in removing drafts from the property, and we’ve now replaced all the leaky doors and windows.
So it’s going to be really interesting to see how we heat our property this winter. We may just turn down the target temperatures in the northern part of the house to 18-19C just to prevent damp, and only heat the main living areas and master bedroom.
This should, in practice, drop our electricity consumption, but I’ve seen that even when our air source heat pump is idling on a mildish day (8C) it’s still consuming in the region of 2kWh, which equates to around 50kWh per day. At our current tariff of 33p/kWh that’s a whopping £16.50/day or £495/month. And that’s with the pump idling.
What happens if the temperatures drop to around 0C for a few weeks? The consumption will go up to 3-3.5kWh/hour almost doubling the running costs, and we certainly can’t afford to be forking out nearly £1,000 for heating per month.
So what do we do? Do we run in hybrid mode with HVO? Do we just use the heat pump? Just HVO? Do we just turn off our heating altogether and see how cold we get? We’ll have to see.
For us the challenge is that we need to heat a relatively large footprint and our heat pump (not being a high temperature unit) needs to run all the time to keep the house at temperature. If we turn it off for a day (or if there’s a blackout), and it’s less than 6C outside, it’ll take at least 24 hours to get the house back to temperature.
So we’re going to have a plan A, B and C and roll them out as and when we need to. The final plan will be to invest in mohair socks and blankets, along with some thermals and walk around like the Michelin man.
What’s your plan when it comes to heating this winter? Are you at all concerned or do you have things under control? Drop a comment below.
Thanks for the post. I wonder if all in one body warmers are going to come into fashion, a sort of duvet onesie, in order to cut down on house heating but keep the body warm!
😂 I’d certainly consider getting one.
Hi Mars, 2kW as a minimum capacity seems very high. If you have a COP of 3 then your houses is using 144kW of heating per day. Does this tally with your heat loss calculations?
My 16kW Daikin unit will ramp down to around 700W of consumption before shutting of, 2kW if that is the minimum speed of the compressor seems high. Maybe ask your supplier what the minimum speed/consumption of the system is.
In January 2021, we consumed 2,231 kWh of electricity (most of which was heat pump driven). We’ve used a 2021 figure because we ran bivalently this past winter with HVO. I’ll ask GES about minimum speed and consumption.
Just for comparison our total consumption in a 3 bedroom detached house was 1200 kWh Dec-Jan maintaining a constant temperature of 20 degrees during the day.
Reading this makes me dither slightly with our almost committed decision of heat pump installation (HT Daikin unit). My instinct is telling me to plough on and not question what was, until only a few months ago, a logical and almost financially justified (ignoring payback) decision. The dynamics of everyones heating choices are tragically now in the hands of a deranged Russian individual, and global supply and demand factors. I never thought it would be so difficult. SWS
You could flip your thought process.
“What could i do to half my annual energy consumption or cost and still keep warm? ”
That may help thinking about big changes, requiring quite a bit of capital expense and time. It doesn’t mean you will ever make the changes but it might be a useful exercise if you haven’t already done it.
I don’t know if I am missing something with Heat Pumps.
I arrived here by searching for something else and thought I would hang around. This is my humble opinion and others circumstances might be different, so please don’t judge me.
I am extremely environmentally and cost conscious in regards to Energy, however, in non of my calculations can I justify the cost of installing a Heat Pump for Hot Water or Heating.
However, I believe in Heat Pump technology in regards to Air to Air Heat Pump (I’ll refer to as Air Conditioners – AC) and have used a single 12,000BTU AC unit upstairs and portable oil heaters driven by 5kw of Solar Panels connected to a 4kw Inverter. Oil heaters and Air Conditioner has kept the house warm during the day as I tend to allow heat to increase to 26 degrees while out, which when I arrive home the natural cooling rarely means that the Gas boiler needs to be Fired up.
The last 12months, our Gas usage is 5400kwh and this is mostly Hot Water from the Combi during the whole year, plus a 20-40minute run of the boiler to ‘top-up’ the house on very cold nights.
The reason I have landed here, is that for the last 5yrs, I’ve ‘been getting round’ to converting Hot Water to use surplus Solar. It is only now that I have the threat of expensive Gas in Sept 2024 that I am getting off my bottom to sort it.
Of the 5400kwh used, as I mention, most is baths and showers’ throughout the year. With Putin’s antic’s in regards to Gas, I have LPG cylinders and a boiler conversion kit on stand-by for Winter should Gas supply become an issue. This is the driver by converting the bulk of Gas used for Hot Water to Solar. The intention is to disconnect Mains Gas and stick to LPG as supply is more secure if purchased ahead and kept to one side and 40% of the LPG can be covered by savings on Standing Charges.
Calculations are tending to show I’d need around 1,200kw Gas supplied heat in the depth of Winter and the rest of the year, Solar driven Air Conditioning for direct heating is a better option. Therefore, I am fitting 2x Air Source Split Air Conditioners, one as a new install in the downstairs area and the other to replace the ailing one that has got us through the cool Spring and last weeks heatwave maintain the whole house at 22’C.
I’ll have enough Solar to maintain 500 litres Hot Water at over 75’C, up to 90’C to give reserve capacity. To power the house, charge batteries and in summer charge an EV for free twice a week.
I just cannot see the justification of the cost of a Heat Pump for both HW and CH, other than a very cheap unit off that famous Auction site for £1500 to heat just the Hot Water quicker for less Solar input, freeing up more for the EV.
One big reason I would absolutely not, at this time, entertain a Heat Pump is that the UK is too heavily reliant on Gas for electricity. At between 45% and 75% electricity generation from Closed Coupled Gas, what happens when all these Heat Pumps, new EVs, cooking, lighting etc, creating demand should Gas supply become restricted or rationed? At a time of year when COP ratios are lower and Auxiliary Heaters are activated making it probably more efficient to switch on Immersion Heaters as pointless running the mechanics of the unit to pump it around the system.
Although many laugh at me when I suggest, Gas and ultimately electricity supply looks likely to be an issue this year – I may or may not be proven wrong, but right now it isn’t looking good. When my local Councilor thinks its funny in March to suggest such scare stories, to hear in July that some councils are building “Welcome Zones” people can go to to stay warm and alive over Winter.
So, with a heat pump, it pushes more reliance on Grid supply at a time this supply may be affected. My Gas boiler can be run from the UPS output of the Inverter or Generator and as long as I can get fuel into it such as Methane or LPG, I can have 30kw of heat output for 85watts of electricity input.
Is it wise to continue installing technology that is putting more strain on Gas supplied electricity when during Winter they are at their lowest COP value. Should government instead concentrate efforts into ways to reduce Grid demand itself and with it, Gas consumption, such as devising better ways to finance Solar installations to those that want it, who would massively benefit from the Energy savings but cannot afford it. Then install better ways to use the gift the sun gives than sell it for 4p/kwh?
In my scenario, £15,000 is at a 35yr payback at todays rates for the 80 days Solar wouldn’t cut it.
I am not in anyway calling Heat Pumps, but from experience of directly heating using Air Conditioners, I cannot see a reason to renew the heating system and radiators. One massive benefit in the warming climate, is I have had completely free to run Air Conditioning, something we insulated homes will desperately need to stop them roasting occupants in summer in years to come.
My Energy Bill is £65/month and due to fall or at least, remain the same in October, once Hot Water tanks are installed.
If nothing else, have a portable Calor Gas Heater and a couple of bottles ready in case this winter – it may just save your family freezing!