ASHP or Oil Boiler

[IanR]

13 minutes ago, Dave Jones said:

 

heat pump = giving up limitless cheap hot water and going back to the old days of tanks and cylinders.

 

they are viable for niche builds where ££££ can be spent getting every last detail to make them work but be very wary on a retrofit. They guzzle electric in the winter.

 

We need a "disagree" emoji to save time replying to such rubbish.

 

13 minutes ago, Dave Jones said:

They guzzle electric in the winter.

Which would be less than a third of the kWh of Gas/Oil required to heat the same property. Same price as Gas, cheaper than Oil or LPG.

Edited July 20, 2021 by IanR

[jack]

11 minutes ago, ProDave said:

I think the big issue with ASHP's is there are a lot of people (and cowboy installers) expecting to swap a gas or oil boiler driving radiators for an ASHP and expect it to work.  It won't.  This is going to lead to a lot of people disappointed with ASHP's and plastering the internet saying how rubbish they are rather than how rubbish the system design (or lack of design) was.

 

This. Look at the massive variability in estimated heating requirements that different companies will give on the same property. It isn't the tech that's the problem, it's the industry.

[SteamyTea]

38 minutes ago, Dave Jones said:

 

heat pump = giving up limitless cheap hot water and going back to the old days of tanks and cylinders.

 

they are viable for niche builds where ££££ can be spent getting every last detail to make them work but be very wary on a retrofit. They guzzle electric in the winter.

Ok, to clear this up, and stop you trolling, can you show us your heat loss calculations for your house, and your DHW useage. Then show us all why it is not possible to have a HP system deliver the same outputs.

Then show us the difference in running costs, and installation cost, rather than vague and misleading statements.

If you are not willing, or able (which we both know is the real reason) to supply this information, then you don't have anything to contribute.

Edited July 20, 2021 by SteamyTea

[Carrerahill]

31 minutes ago, jack said:

 

This. Look at the massive variability in estimated heating requirements that different companies will give on the same property. It isn't the tech that's the problem, it's the industry.

Agreed - I am not personally a mechanical engineer (I'm electrical) but I work in M&E so my colleagues are mech guys and in M&E project meetings we must sit and listen to the other disciplines discussions - needless to say, you pick things up to a point you are familiar with other building services.

 

We are currently the stage 4 M&E design consultants and checking engineers for a D&B hotel, our guys designed it with one system but the M&E contractor wants to use Mitsubishi for the ASHP's, now this is for heating 4000 litres of water with pre-heat cylinders and heated buffers and all sorts, its a big system but the change to Mitsi is a nightmare, the whole system is having to be redesigned and re-calculated by the M&E contractor (who is now regretting it I think because they are spending more manhours on design than they will save on kit). They are also going to need to have a booster immersion tank to bring the water temp up to the hotel spec temp because the Mitsi system won't get it hot enough.

 

Things got a little heated recently between the PM and the M&E contractor, where the main contractor PM wanted to know what exactly the issue was, we stated that the system we designed was based on various temps and figures and flow rates from manufacturer A - but M&E contractor wants to use manufacturer B - because of the massive variances in the way these things all work, its not just comparing apples to apples and I think it is this issue that is creating the minefield. 

 

Gone are the days where anyone with half a brain could spec a gas boiler or cylinder etc. and as long as they got water volume and BTU's etc. right it would probably work, I think annoyingly we are entering an era where these systems are going to need to be properly designed, at least until they become more common and more importantly widely understood by all.

[Mr Punter]

Oil boilers can be smelly, dirty and expensive to run, so I can see how a heat pump can compete.

 

Where a property is served with mains gas, which is used in 85% of UK homes, there is no compelling reason for a heat pump.

[IanR]

17 minutes ago, Mr Punter said:

Where a property is served with mains gas, which is used in 85% of UK homes, there is no compelling reason for a heat pump.

 

Apart from future proofing your home at no additional cost (with the help of RHI), rather than using a technology with a shelf-life.

[Mr Punter]

1 minute ago, IanR said:

Apart from future proofing your home at no additional cost (with the help of RHI), rather than using a technology with a shelf-life.

 

The RHI would pay out £3,290.  I doubt the figures would justify it.  Both systems are probably good for 15 years and swapping out a gas boiler is half the cost of ASHP.  The electricity would probably cost more than the gas.

[SteamyTea]

1 hour ago, Carrerahill said:

I think annoyingly we are entering an era where these systems are going to need to be properly designed,

Why 'annoyingly'?

With the current system of gas boiler installations, there is probably very little thermal design involved.  This promotes inefficiency at all levels.

It also highlights a problem with not having to pay a direct price for externalities, such as climate change mitigation and infrastructure updating/upgrading.

 

Taxable commodity	Rate from 1 April 2018	Rate from 1 April 2019	Rate from 1 April 2020	Rate from 1 April 2021
Electricity (£ per kilowatt hour (KWh))	0.00583	0.00847	0.00811	0.00775
Gas (£ per KWh)	0.00203	0.00339	0.00406	0.00465
LPG (£ per kilogram (kg))	0.01304	0.02175	0.02175	0.02175
Any other taxable commodity (£ per kg)	0.01591	0.02653	0.03174	0.03640

 

https://www.gov.uk/guidance/climate-change-levy-rates

[IanR]

1 minute ago, Mr Punter said:

 

The RHI would pay out £3,290.  I doubt the figures would justify it.  Both systems are probably good for 15 years and swapping out a gas boiler is half the cost of ASHP.  The electricity would probably cost more than the gas.

 

RHI paid out considerably more for me, but even at £3,290 would cover the difference on a new build. Cost of Electricity v. Gas is in parity today, but Gas will soon be loaded with the green tax that will be coming off of Electricity, and then I expect additional carbon taxes to be added to Gas to make it less competitive.

 

There is no compelling reason to install a Gas boiler in a new build, let alone Oil or LPG

[Mr Punter]

3 minutes ago, IanR said:

There is no compelling reason to install a Gas boiler in a new build, let alone Oil or LPG

 

I am doing 3 flats and could find no reason or practical way not to fit gas combis.

[IanR]

2 minutes ago, Mr Punter said:

 

I am doing 3 flats and could find no reason or practical way not to fit gas combis.

 

The OP isn't building flats...

[Mr Punter]

2 minutes ago, IanR said:

The OP isn't building flats...

 

No, I am.  The OP is not on mains gas either and I earlier commented 

1 hour ago, Mr Punter said:

Oil boilers can be smelly, dirty and expensive to run, so I can see how a heat pump can compete.

 

[billt]

1 hour ago, SteamyTea said:

Then show us the difference in running costs, and installation cost, rather than vague and misleading statements.

 

I'm not Dave Jones, but live in a bungalow with terrible thermal properties.

 

We had the gas boiler replaced about a year ago for one of the most efficient that we could find. It cost £2000 including changing a couple of radiators and a few other odds and ends. The boiler is invisible, in a kitchen cupboard. I don't know how much a heat pump installation would cost, but it's likely to be in excess of £10,000, need significant plumbing modifications and add a big, unsightly box outside the house. We've got the space for it, but many modern houses haven't.

 

Gas costs 2.62p/kWhr, so say 2.9p allowing for boiler losses. Electricity costs 16.1p/kWhr. Assuming COP of 3, which would be a pretty good average for a retrofit in a typical house, that's 5.3p per kWhr - twice the running cost of gas. Over the last year we've used about 29,000 kWhr of gas (yes, it's a lot and I'd like to get it down, but that's going to be difficult). That means that a heat pump would cost over £700 p.a. more to run than gas, with current prices.

 

Of course, if the choice is between a new oil system and a heat pump system, the heat pump is a more sensible choice, as long as the system is competently designed.

 

Apart from his exaggeration of the COPs, Roger Bisbee's (?) rant was pretty much spot on. Bear in mind that he's talking about the existing housing stock, not well insulated, well built self-builds.

[IanR]

4 minutes ago, billt said:

I don't know how much a heat pump installation would cost, but it's likely to be in excess of £10,000, need significant plumbing modifications and add a big, unsightly box outside the house.

 

Yes, if you don't plan a significant renovation, then your situation is different to the OP, so you would need to include replacement heat emitters and additional plumbing into the ASHP costs, which probably means Gas is the more cost effective solution today. Although I'd still run the figures through RHI, just in case it closed the gap.

 

7 minutes ago, billt said:

Assuming COP of 3, which would be a pretty good average for a retrofit in a typical house,

 

As an average COP, across the whole year, that would not be a a good assumption. If you were renovating, and designing for a low temp heating system, exceeding 4 would be achievable.

[SteamyTea]

28 minutes ago, billt said:

cost £2000 including changing a couple of radiators and a few other odds and ends

So a basic replacement then.

Isn't this like replacing a broken ten year old car with an identical, ten year old car, but with lower milage.

29 minutes ago, billt said:

but it's likely to be in excess of £10,000, need significant plumbing modifications and add a big, unsightly box outside the house.

And this is like replacing the broken banger with a new Tesla.

 

If you really want to compare prices, you have to do it on the same basis, not on an arbitrary one like power output only.

A better gauge would be installation cost / (running cost / annual energy yield)

 

[ProDave]

The "problem" coming up is the government have decided to outlaw fossil fuel boilers to decarbonise home heating.  A very worthy aim given the need to reduce / eliminate CO2 emissions.

 

But I don't believe it has actually been thought through.  It is just an ambition, and a stick (banning new fossil fuel boilers) but no actual plan of how to achieve it.

 

Sticking an ASHP in every house is not the solution.  It needs a LOT more than that to much of the UK housing stock to properly insulate it and draught proof it etc.  I don't believe government subsidised schemes will deliver well engineered solutions that offer good value for money for either the home owner or tax payer.

 

And then, when all the homes are heated with heat pumps, all the new generation capacity installed to power them must not use fossil fuels otherwise you have failed in reducing CO2 emissions, just moved it.

 

And all this happening when transport must also move to non fossil fuels.

 

Just where is the plan for all this non fossil fuel extra electricity generation and upgrades to the distribution network to make it all work?

[MikeSharp01]

4 minutes ago, ProDave said:

Just where is the plan for all this non fossil fuel extra electricity generation and upgrades to the distribution network to make it all work?

Probably 'oven ready' like so many other plans - targets are one thing delivering them seems not to be an issue - the target is the target - I will only be in power for a short time, I will speak great words and leave it to the next bunch to make the hard choices, after all nobody will vote to be taxed to the hilt so we can de-carbonise will they?

[Dave Jones]

6 hours ago, SteamyTea said:

Ok, to clear this up, and stop you trolling, can you show us your heat loss calculations for your house, and your DHW useage. Then show us all why it is not possible to have a HP system deliver the same outputs.

Then show us the difference in running costs, and installation cost, rather than vague and misleading statements.

If you are not willing, or able (which we both know is the real reason) to supply this information, then you don't have anything to contribute.

 

sorry i do not lower myself to petty name calling. Shame this forum doesn't have an ignore feature so i can block immature name callers like you who seem to hate an opposing point of view.

[SteamyTea]

3 hours ago, Dave Jones said:

Shame this forum doesn't have an ignore feature

It does.  Tim whatever his name was has already blocked me.

Shame you do not want to engage in the heat pump debate posting up biased, unfounded, opinions, and then not backing them up is now called trolling.

[patp]

On 19/07/2021 at 17:14, ProDave said:

What do they call high electricity costs?  That is probably cheap developer house and lack of insulation rather than anything fundamentaly wrong with ASHP heating.

The house cost Circa £850K so not, I would say "cheap". As to the build quality, the developer had a good reputation amongst all the trades but who knows? They do have a lot of glass and those high vaulted ceilings.

[billt]

19 hours ago, SteamyTea said:

So a basic replacement then.

Isn't this like replacing a broken ten year old car with an identical, ten year old car, but with lower milage.

And this is like replacing the broken banger with a new Tesla.

 

If you really want to compare prices, you have to do it on the same basis, not on an arbitrary one like power output only.

A better gauge would be installation cost / (running cost / annual energy yield)

 

 

A stupid comparison. It is fitting a new, high efficiency boiler, not replacing an old boiler with another old boiler.

 

If you'd read my post you would have seen that the comparison was on the same basis; the cost of a new gas boiler or a new heat pump in an existing system. The actual energy use and the actual energy costs show that the heat pump system would cost significantly more to run. I didn't mention power output at all.

[SteamyTea]

6 minutes ago, billt said:

didn't mention power output at all

No, that was a general comment to highlight how hard it is to compare different technologies.

But out of interest, what boiler did you get fitted, and how is it working out, as cheap to run as you imagined?

[Carrerahill]

On 20/07/2021 at 14:34, SteamyTea said:

Why 'annoyingly'?

 

“Annoyingly” because people don’t like paying for design services, even at the top of the construction pile, contractors and developers don’t like paying for things to be designed, they knock you down on price and want everything they see as “non-essential” taken out the scope. So, what will happen, in reality, and what happens currently in other changing playing fields is that the installation will be done without design or without proper design. The net result is inefficiencies or inadequate or poorly functioning systems.

 

You will also get the boiler installer who diversifies into ASHP as his boiler installs fall off who will go on a training course then claim to be the expert, this is true for a small minority but many just become so called “experts” then throw about poor information and worse, install systems based on said poor information.

 

If more things were designed then we would be in a better, more efficient, cost effective world in the long term, but many want to see the capital costs lowered, particularly developers.

 

I know for a fact that a developer is currently installing 164 No, 305W Peak, solar panels on a building, connected to nothing. Reason being that the LA accepted their existence, but little do they know they don’t go anywhere. Why on earth I hear you ask, well what is the benefit to them? They saved £40,000 or something on the inverters, connection back to the MSB etc. etc. and the install time. If that is their attitude, why would they want to waste any money on things they can just slap in without design?

[SteamyTea]

9 minutes ago, Carrerahill said:

I know for a fact that a developer is currently installing 164 No, 305W Peak, solar panels on a building, connected to nothing

Would they like me to come up and take a few off their hands?

 

Mathew Syde was talking about this just the other day.

https://www.bbc.co.uk/sounds/play/m000xm77

[joe90]

1 hour ago, SteamyTea said:

Would they like me to come up and take a few off their hands?

Can I join the queue? ?‍♂️