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Electricity use for heat pumps - comparing homes and consumption

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Air Source Heat Pumps (ASHPs)

Last Post by glpinxit 2 years ago

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Rad1o

(@rad1o)

Active Member Member

Joined: 3 years ago

Posts: 4

Topic starter 14/02/2024 12:18 pm

Hello,

We are new to heat pumps.

I just want to ask for numbers to be able to compare.

We live in the Midlands and had a Grant Aerona 3 17KW installed in September. Our base electricity consumption for a 5 bedroom house before heat pump installation was a stable 400 - 450 KwH per month.

We had an aditional 1000KwH when the heating period started and pretty much the same for November, December and January. We keep the house at 20.5°C with only minor setbacks as the pumps struggles to catch up bigger temperature drops and when the temperature dropped to -9°C for a few days I kept the 20.5°C all day. The pump managed o.k.

What kind of electricity usage do people with have?

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Gary

(@gary)

Prominent Member Member

Joined: 3 years ago

Posts: 350

14/02/2024 12:48 pm

My usage in non-heating months is similar to yours 450kwh a month, adding heating in Nov was an extra 400kwh, Dec 500kwh and Jan 700kwh. This is a 5 bed house in Oxfordshire, I have an 8.5kW heat pump.

What flow temperature are you running at? Mine varies between 32C and 40C depending on outside temp.

👍

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Rad1o

(@rad1o)

Active Member Member

Joined: 3 years ago

Posts: 4

Topic starter 14/02/2024 2:16 pm

I have never really charted or even checked the parameters. I left them as the installer had set the system.

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cathodeRay

(@cathoderay)

Illustrious Member Moderator

Joined: 4 years ago

Posts: 2357

14/02/2024 2:28 pm

There are a number of threads on this forum, some very detailed, that cover energy and/or electricity use (both matter, and of course they are related, by price per kWh). A number of us collect and post very detailed numbers for energy use. One mega-thread on the matter is one I started on setbacks: Do setbacks save energy without compromising comfort? The problem of recovery boost after setback to manage the inherently slow recovery built into most heat pumps has also been covered in great detail, and is still something of an 'ongoing matter for debate', though I have to say I think if you can add a recovery boost (which deals with comfort), then modest savings are on balance possible in mild to moderate outside air temperatures, but perhaps not once the heat pump gets into defrost territory.

Midea 14kW (for now...) ASHP heating both building and DHW

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Gary

(@gary)

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Posts: 350

14/02/2024 3:52 pm

I would look at some of the threads on the Grant heat pumps and check you settings they probably aren't optimal and could just be running at a constant flow temp

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SUNandAIR

(@sunandair)

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Joined: 3 years ago

Posts: 504

14/02/2024 5:14 pm

I might almost have just copied @gary s figures with some small differences.

Ours is a 4 bed old house,180sq mtrs, no u/f heating just 16 radiators. Old farm workers cottage. Insulated internally.

My heating in Nov was 405kwh, Dec 451kwh and Jan 720kwh. We are located in The Cotswolds, I have an 8.5kW heat pump. We have low mass internally and no under floor slab to heat up.

Regarding flow temperature with radiators we can just about get down to 32C and more likely to be 35 to 40C depending on outside temp.

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Morgan

(@morgan)

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Joined: 5 years ago

Posts: 664

15/02/2024 9:05 am

3-bed detached house in rural E Midlands. 10 rads, no ufh. Double glazed and cavity wall insulation. 11.2KW Ecodan. The heating is set to 20c, with no setbacks. 24/7 Auto Adapt. I am hoping to get a Heat Geek to come and have a look over my installation and set up.

June 23 CH off; 160.

CH and DHW - Nov; 526. Dec; 611. Jan; 809.

Retrofitted 11.2kw Mitsubishi Ecodan to new radiators commissioned November 2021.
14 x 500w Monocrystalline solar panels.

2 ESS Smile G3 10.1 batteries.
ESS Smile G3 5kw inverter.

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Mars

(@editor)

Illustrious Member Admin

Joined: 5 years ago

Posts: 3678

15/02/2024 9:18 am

@morgan what’s prompted you to get a Heat Geek installer out? Your consumption numbers look good.

Get a copy of The Ultimate Guide to Heat Pumps

Subscribe and follow our Homeowners’ Q&A heat pump podcast

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Mike Patrick

(@mike-patrick)

Honorable Member Member

Joined: 5 years ago

Posts: 183

15/02/2024 9:31 am

Many of the above , in my dreams.

2023, June 479, Nov 1,120, Dec 1,359, Jan 2024 1,491

These are total kWh per month from which you can subtract 8-10kWh per day for non-ASHP use - say 300kWh per month.

100% electric home. 10KW Grant Aerona, 3 bed detached (150 sqm), mixture of cavity wall insulated new build and internally insulated original stone, double glazed, UFH no radiators. 20c heating. ASHP left on same settings 24/7. UFH off during summer months, 2 occupiers.

Mike

Grant Aerona HPID10 10kWh ASHP

👍

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Morgan

(@morgan)

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Joined: 5 years ago

Posts: 664

15/02/2024 9:58 am

@editor You think? I recall a post by @heacol suggesting the removal of certain components such as Honeywell valves and particular pumps etc could improve efficiency by large amounts. I'm sure I can gain improvements.

These figures are for ASHP consumption only.

Retrofitted 11.2kw Mitsubishi Ecodan to new radiators commissioned November 2021.
14 x 500w Monocrystalline solar panels.

2 ESS Smile G3 10.1 batteries.
ESS Smile G3 5kw inverter.

👍

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Kev M

(@kev-m)

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Posts: 1276

15/02/2024 10:14 am

14kW Ecodan, rural East Midlands, largish 1990 bungalow 21.5 throughout mostly 24/7. Heating and HW combined- December 699kWh COP 2.95 January 947kWh COP 3.34.

Same supplier as @morgan so I'll be interested in what his heat geek says.

👍

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Morgan

(@morgan)

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Posts: 664