My air source

[tommy12398]

Hi, I built a 4 bedroom detached house in 2014. The council said I could only have ground or air source.  I couldn't afford ground, so a 14kw samsung air souce was put in through a compy called joules.  It works very well. I was happy with the system.  The trouble is back then electric was 12p kwh. Now it's 28, going upto 42 in October. My bills are massive. I'm useing around 15000kw. I got a qoute to fix electric,  came in at £8000. I'm seriously thinking of ripping it out and putting lpg gas in! 1 liter of gas is equivalent to 7kw. Say gas at 50p a liter that's 7p kwh. £5000 to install gas? Anybody got a better idea?

[joe90]

3 minutes ago, tommy12398 said:

I got a qoute to fix electric, 

What does this mean?. If your using this amount of “energy” your house is not very well insulated and any “fuel” type will use a lot. From my understanding electric is about 3 or 4 times the price of natural gas but LPG is more expensive than that, if you have a decent COP with your ASHP (say 3) then a change to LPG will not cost a lot less. Others will be along with accurate figures shortly.

[SteamyTea]

You are making a knee jerk reaction to the recent prices rises.

Medium term, electricity will drop in price (and you are being subsidies £400 this year).

Electricity, if we keep up our current renewable deployment, will reduce the price more.

Gas is being phased out, not very quickly, but it is going to go, so the kWh (not kw, kW, or kW/h even).  One area that this government may look at is the green taxes on electricity and not on gas, swap them over and at todays prices electricity will be about 22p/kWh and gas about 14p/kWh.

Throw in the CoP of an ASHP and that makes a kWh about 8p for an ASHP and once efficiency of gas boiler is taken into account, about 9p/kWh.

 

Probably cheaper to reduce your usage.

Edited August 7, 2022 by SteamyTea

[AliG]

I don't think 15000kWh is excessive assuming it includes heating, hot water and general electricity usage.

 

The best thing to do is get yourself on an Octopus Go type tariff and then run your heating and hot water as much as possible during the night.

 

I recently did this and shifted over half my electricity usage to overnight at the cheap rate.

 

In your case, I would try to heat our hot water tank during the cheap period and counterintuitively run your heating with the thermostat set 1C higher during the night than during the day, so it would run overnight and then the heating would switch off for most of the day until the house cooled down.

 

We have gas and I am considering just using the immersion to heat water from October onwards as it will be cheaper to do this during the night on Go than it will be to use gas during the day.

[JohnMo]

So explain your heating system 

 

What does your EPC say your heat demand is? Or if you're got heat calculations what does that say?

Flow temperature?

Return temperature?

UFH or radiators?

How are you controlling your heat pump, thermostat in each room, or something else? Running all the time or short cycles on and off?

Pipe sizes if you know them?

What are they quoting to fix?

[tommy12398]

15 minutes ago, joe90 said:

What does this mean?. If your using this amount of “energy” your house is not very well insulated and any “fuel” type will use a lot. From my understanding electric is about 3 or 4 times the price of natural gas but LPG is more expensive than that, if you have a decent COP with your ASHP (say 3) then a change to LPG will not cost a lot less. Others will be along with accurate figures shortly.

I'm on octopus standard tariff.  They say the air source has a cop of 3. But I understand only at certain temperatures. My house has a epc c. All cavity wall insulation and roof of course.  As with gas. I can get a bulk tank with calour for 50p a liter. Even if I use 3x more gas. Its still alot cheaper. 7p kW x 3 that's 21p kW. I herd come January upto 60p kW.  I like the air source but the figures aren't adding up. I have  underfloor  heating set at 19. Rads upstairs. Set at same. I leave heating at same level day or night in winters 

[tommy12398]

I've had a talk with my local plumber who also fits renewable. He said he would never put one in. I do live on a very rural area of North Yorkshire.  So mybe one reason why my usage is high. But my mum and dad live a litte further up in a covered barn with same epc. There house is alittle smaller. She last filled her lpg gas tank up in November for 495. Even if I used double this . It would still be far cheaper than air source 

[ProDave]

Lots of issues here.  15,000kWh is about 2.5 times our total usage so just how big is the house?  if not big, then insulation is disappointing for a 2014 house.

 

Comparing LPG cost with someone who last filled their tank 10 months ago is not a valid comparison, that LPG is likely twice as much now.

 

ALL fuels will have virtually quadrupled in cost by the end of the coming winter.  If anything electricity will have gone up less % than gas.

 

There is not much any of us can do other than somehow pay the bills.  For anyone at the early stages of a build, this reinforces why we keep saying Insulation, Air tightness and MVHR and Solar PV to help a bit more.

 

When the "council" said you could only have a heat pump, was this a planning condition, or was it building control?

 

Do you have any solar PV?  Would you consider it?

[tommy12398]

My house is 200sq feet. I think the electricity is high. I have fitted a 6kw solar. This summer. But cannot see it doing much on a cold misty wet day in January.  Lpg gas is a by product of petrol. Mum says its at 42p. From 35 in November.  Even if it got to a £1 a liter. Still cheaper. My bills last year was 200 a month in winter at 15p.  Now my electric is 29p for now. So you can see how expensive it's gonna be. At these prices gas will pay for its self quickly.  Can anyone see electric coming down anytime soon. 

[SteamyTea]

Are you trying to run the ASHP like a gas boiler i.e. only on when you need it, rather than on al the time.

What temperature do you set your DHW at, does it run a disinfectant/legionella cycle?

I it an Ecodan that gives problems with the crankcase heater.

Do you have detailed electrical energy usage via a logger or smart meter?

[SteamyTea]

2 minutes ago, tommy12398 said:

My house is 200sq feet.

Do you mean m².

200 foot² is very small. 18.5 m².

 

 

[tommy12398]

My Dhw is at 46. Once a week it takes it upto 50. Through winter I try to keep everything at a constant temp. Usually 19 degrees.  I let it drop to 17 18 through night.

[tommy12398]

Sorry yes 200m2

[Kelvin]

23 minutes ago, tommy12398 said:

I've had a talk with my local plumber who also fits renewable. He said he would never put one in. I do live on a very rural area of North Yorkshire.  So mybe one reason why my usage is high. But my mum and dad live a litte further up in a covered barn with same epc. There house is alittle smaller. She last filled her lpg gas tank up in November for 495. Even if I used double this . It would still be far cheaper than air source 

Lots of plumbers say that. 
 

Presumably your heating is off just now and the ASHP is just being used for hot water? Do you have PV and if so have you looked at solar PV. 
 

I rent an old farm cottage with hollow walls. It’s chuffing freezing in the winter and heated by an oil fired boiler that I don’t have much control over. I bought 1000l of oil in December for £647. I bought another 1000l in  March (just before it went crazy) but it still cost £947. At one point it would have cost almost twice what I paid in December. I don’t know how much LPG costs but it won’t be anywhere near what it cost last November. 

[ProDave]

How much electricity are you using per week or per month just now (summer with heating turned off)?  in kWh not price?  Actual readings not what you are paying per month.

[tommy12398]

For July I've used 301kw. But exported 452kw. My heating is on holiday mode through summer. I.e only comes on when below 14 degrees. But still on for hot water. In June I used 268kw. Is this high for summer

Edited August 7, 2022 by tommy12398
More info

[Kelvin]

There’s one possible issue then. The goal for PV generation ought to be you use as much of it as you can. You could look at fitting a solar PV immersion diverter so any excess you generate gets used to heat your water. You could also look at cheap night rate tariffs and run as much as you can during those hours. 
 

It seems your house isn’t that well insulated nor possibly as airtight as you really want. Neither are that easy to fix after the fact. 

Edited August 7, 2022 by Kelvin

[tommy12398]

Is a EPC score of c bad. When they did it they said it was very nearly a B. What's other people with or without air source using a month through summer? It never gets below 14 in summer even if I leave all doors open? 

[Kelvin]

17 minutes ago, tommy12398 said:

For July I've used 301kw. But exported 452kw. My heating is on holiday mode through summer. I.e only comes on when below 14 degrees. But still on for hot water. In June I used 268kw. Is this high for summer

I used 423kW last month but we have an EV so about 150kW of that was charging the car. We also have electric showers and have had a lot of folk visiting and staying over so I’d say our usage has been a little higher for July. 

[tommy12398]

My wife does the baking for a local outside catera. So to be fair some times 2 electric ovens can be on 2 to 3 hours in a day. But not everyday. Looking at your electric a month I would say mines in line. Have you air source. 

[tommy12398]

Are the new generation ashp more efficient and less expensive to run. Mines 8 years old now. Would a newer or different brand save me money 

[Kelvin]

Oil fired boiler and a wood stove (we get free wood) We rent a 50 year old farmhouse (we are building a house nearby) It has an EPC rating of E! 

[Bozza]

I live in NE Scotland.  It is a cold place and we had a cold winter.  My house is 214 sqm.  I have ASHP exclusively.  no solar etc.  My actual annual kw useage is 9200kw.  I work from home and stuff is on day and night and I’ve a wife and kid who never seem to know how to turn lights off.  

 

In past month I’ve used 350kw as heating hasn’t been on just water.   Luckily I fixed last summer so in past month I’ve been paying £80 something like that.  That’s not allowing for the funding payments I get fir installing ASHP.

 

Putting tariffs aside your useage is significantly higher than mine that in itself is an issue for you.  Likely to be you’ve got a poorly insulated house, surprising if built in 2014, and/or you’ve got issues with your ASHP settings?

 

There are a lot of plumbers out there who say they would never fit ASHP.  Probably because they are not qualified to do so and it’s good for their business to diss ASHP.  I would say don’t fit ASHP to a poorly insulated house though in fairness.    
 

 

 

 

 

 

[tommy12398]

I really don't think the ashp in the real world are as efficient as they say. When building the house one my biggest bills was insulation!!. I don't think it should use this much. But when joules serviced it last year. They did all calculations and said 15000kw is around where they expected the annual house usage. The trouble is electric so dam expensive, personal I think other heating like lpg us far far cheaper 

[Kelvin]

Well Bozza is using significantly less electricity than you in a slightly bigger house…