Little Stud Barn

Who wrote the article?!! Was it one of those "advertorials"? SAP will push you towards renewable solutions. Any heating source that's poorly specified is going to perform horribly. ASHP have to be paired with an air tight, well insulated structure to perform well with it's lower heat levels compared to oil/gas. There's no reason the running costs need to be more, you're in control of when it runs and can pair it with Solar PV and flexible tariffs. You're not in control of oil prices although you have a tank and some oil to fall back on there but when you refill, you have to pay whatever the market rate is. 

As ASHP is newer technology, the market % means there are less of them being installed compared to Gas boilers so economies of scale haven't kicked in yet, so there's an obvious gap. 

At the end of the day you're in control of your budget and choosing the best means to heat your house within the bounds of legislation. I just wouldn't knock ASHP because of one article, that's all. The same publication have "air source heat pumps explained" available online if you search from 6th February 2019. 

Best of luck with whichever choice meets your needs. 

5 minutes ago, mike2016 said:

ASHP have to be paired with an air tight, well insulated structure to perform well with it's lower heat levels compared to oil/gas.

Stop saying that, it is just wrong.

Any power source that is specified wrongly will cause problems, ASHPs are no different.

And power, energy and temperature are different things, the word 'heat' in thermodynamics means energy, not temperature.

Edited December 7, 2020 by SteamyTea

9 hours ago, mike2016 said:

Who wrote the article?!! Was it one of those "advertorials"? SAP will push you towards renewable solutions. Any heating source that's poorly specified is going to perform horribly. ASHP have to be paired with an air tight, well insulated structure to perform well with it's lower heat levels compared to oil/gas. There's no reason the running costs need to be more, you're in control of when it runs and can pair it with Solar PV and flexible tariffs. You're not in control of oil prices although you have a tank and some oil to fall back on there but when you refill, you have to pay whatever the market rate is. 

As ASHP is newer technology, the market % means there are less of them being installed compared to Gas boilers so economies of scale haven't kicked in yet, so there's an obvious gap. 

At the end of the day you're in control of your budget and choosing the best means to heat your house within the bounds of legislation. I just wouldn't knock ASHP because of one article, that's all. The same publication have "air source heat pumps explained" available online if you search from 6th February 2019. 

Best of luck with whichever choice meets your needs. 

I'm in my sit office at the moment, but I will find the article and let you know who wrote it.

 

1. "Not very eco-friendly" is really difficult to justify. If you look at something like Gridwatch, there is virtually no coal fired electricity left on the grid. That means any extra load on the grid is generated from gas at ~55% efficiency - so any heat pump with a COP of better than about 2 will be significantly cleaner than mains gas (i.e. it's cleaner to burn gas in a power station than at home). Drax is about 40% efficient, so if you're better than a COP of about 2.5 you're cleaner burning biomass for electricity and then using the electricity in a heat pump.
2. A lot of people on here have noted that a professional/MCS install of a heat pump adds a LOT to the price - and certainly monobloc heat pumps aren't difficult at all to install. Work out the cost numbers for yourself rather than believing they're what a magazine article tells you they are.
3. Electricity is always going to be more expensive than anything else per unit, but if you're already on the electricity grid then that isn't a true picture - paying for the extra on your bill is all you have to do in cost and time terms. Oil, biomass, etc. are somewhat more demanding, gas has an extra standing charge, etc.

Can someone with an ASHP here tell us how much they pay per kWH for electricity?

 

Last I looked electricity was 3 or 4 times the cost of mains gas per kWH so the COP of the ASHP was needed just to equalise the running cost.

Yes, 16.09 from octopus energy but we have no mains gas available, I keep saying I may change to economy7, just need to work out consumption/times.

Found this, figures from June 2019..

https://www.confusedaboutenergy.co.uk/index.php/domestic-fuels/fuel-prices

 

 

That puts electricity at between 2  and 4 times the cost of mains gas. Call it 3 times? So ASHP needs a COP of 3 to make the running costs the same. Not just for heating but the average for both heating and DHW.

 

 

6 minutes ago, Temp said:

So ASHP needs a COP of 3 to make the running costs the same.

correct, but only if it’s available!!!!

Well yes but oil isn't that much more than mains gas. 5.6 vs 4.8p/kWH.

Also factor in if you have an ASHP you just pay the unit cost as you have electricity anyway.

 

If you have gas, you have to pay to have it installed (in a new build) and pay a standing charge.  If you have a well insulated new build that standing charge may be a significant proportion of a low usage gas bill.

 

But for many gas is not available so a heat pump makes more sense than the only real viable alternative, oil.

 

 

this is the table that started me on this question.

The full article is in the January edition of Build It.

What worries me is making the wrong decision.

I don't have gas so that's out of the question, but that leaves oil, which we use now or Biomass, but getting the pellets is something to consider.

 

 

To choose Biomass means you have swallowed the greenwash and been led to believe burning something that shoves CO2 up your flue is going to reduce your CO2 emissions.

 

At least with electricity, it is getting greener all the time as more real renewables come on stream.

38 minutes ago, LSB said:

this is the table that started me on this question.

The full article is in the January edition of Build It.

What worries me is making the wrong decision.

I don't have gas so that's out of the question, but that leaves oil, which we use now or Biomass, but getting the pellets is something to consider.

 

 

Would love to see the criteria for those scores ..!!! How do you score environmental impact of installation ..?!

Do they mean manufacturing  impact?

10 hours ago, ProDave said:

To choose Biomass means you have swallowed the greenwash and been led to believe burning something that shoves CO2 up your flue is going to reduce your CO2 emissions.

 

At least with electricity, it is getting greener all the time as more real renewables come on stream.

To right, the basis of the policy was wrong from the start and should only be compared to coal burning, not gas or oil.

10 hours ago, PeterW said:

Would love to see the criteria for those scores ..!!! How do you score environmental impact of installation

So would I.

 

BSI has all the standards and criteria, they are not cheap to buy.

I read the same article and have a similar dilemma except that the property that I’m renovating does have mains gas which means that I’m leaning towards a new gas boiler.

 

 Interested LSB what you decided?

4 hours ago, bradders3109 said:

I read the same article and have a similar dilemma except that the property that I’m renovating does have mains gas which means that I’m leaning towards a new gas boiler.

 

 Interested LSB what you decided?

The more I think, the more confused I become, I've been reading so many articles, but also statements on here where people are horrified at the cost of their electricity bill once they install an ASHP.  As I said we don't have mains gas, so I also need to compare LPG, biomass is not sustainable if you are buying the pellets and they become scarce.

When I eventually make a decision, which won't be in time for the RHI, as not that far along I shall post it, and then probably change my mind.

 

I installed an ASHP and very pleased with it. HOWEVER, it’s a new very well insulated build and very airtight with no gas available, well beyond building regs. If your house is not well insulated etc and you have gas it will be your cheapest (to run) option.

27 minutes ago, joe90 said:

I installed an ASHP and very pleased with it. HOWEVER, it’s a new very well insulated build and very airtight with no gas available, well beyond building regs. If your house is not well insulated etc and you have gas it will be your cheapest (to run) option.

the house to be is still a barn so no insulation at this time.

what state should the dwelling be before installing.  we intend to make it airtight and insulated.

before we start building we first need to remove most of the barn,, including the bits that have to go back.

so, as the build will take years being a total DIY process I guess I don't have to do anything yet.

At what stage of your build did you make changes to allow for ASHP rather than boiler

3 minutes ago, LSB said:

At what stage of your build did you make changes to allow for ASHP rather than boiler

ASHP was always planned from the start, as was UFH downstairs. Due to having to fight fir planning permission I had plenty of time to do my homework (mostly this forum and it’s predecessor). I do have a wood burning stove which is a marmite subject here but we are not dependant on it, it’s a luxury and I don’t have to buy wood. I learnt early on that you only buy insulation once, but fuel you keep having to buy (and it will go up in price).

5 minutes ago, joe90 said:

ASHP was always planned from the start, as was UFH downstairs. Due to having to fight fir planning permission I had plenty of time to do my homework (mostly this forum and it’s predecessor). I do have a wood burning stove which is a marmite subject here but we are not dependant on it, it’s a luxury and I don’t have to buy wood. I learnt early on that you only buy insulation once, but fuel you keep having to buy (and it will go up in price).

Your approach is very similar in lots of way.

It took us years to get planning, we love our current wood burner and will definitely have one, even if just for the look and we are planning on total UFH, but we are single storey. 

My only hesitation is the ASHP, or it will have to be oil or LPG as no mains gas. 

 

We currently have oil and last summer or maybe the previous one the oil price dropped to 24p per litre (wish the car was) so we got a much bigger tank.  We don't use much oil, our current house is a freezing single skin 200 yr old cottage and we have realised that it is not worth heating most of it now the kids have flown the nest as it loses the heat so quickly.  Doing something about that is for the future after we move out, when we have the money or for the next residents if we decide to sell and not rent.

1 hour ago, joe90 said:

If your house is not well insulated etc and you have gas it will be your cheapest (to run) option.

After renovation our property will have externally insulated 9 inch solid walls with and internal air tight membrane.  The extension will be ICF (not sure which yet). Floor slabs will  have 150mm insulation and roof will also be well insulated and airtight.  We will have MVHR.

 

Following the article that LSB referred to I'm still undecided about ASHP or Gas boiler. 

 

As you say we can't control the cost of gas and electricity. Also there is a plan to phase out gas boilers so I would imagine that as time moves on there will be measures taken to 'encourage' people to move away from gas.  This could be a 'green' tax on gas or something like that.  ASHP is the future proofing but maybe that could be a later install when the price comes down.

Go with gas but have boilers etc in downstairs plant room, so when gas becomes the devil on 30 years time,

it’s easy to swap out 

 

if I way more green I would go with ASHP, but for me it’s a cost issue

I am in a simliar positon and have been sitting on the fence between oil, LPG or ASHP for a long time. My present plan is to install the plumbing side of the heating myself to ASHP spec (UFH groundfloor and bathrooms and oversize rads bedrooms.) and carry on sitting on the fence until the last moment. Presently having first fix electrics done.