Get your heat pump quick?

shinytop

Cardew said:

TELLIT01 said:

They were talking to a guy from Friends of the Earth on BBC this morning.  He's the only person I have ever heard claim that they are just as effective as gas boilers.  Every other report I've seen says they don't get water as hot.  He did concede that he isn't saving any money because, being electric powered, they are more expensive to run than a gas boiler.  On that basis there is a considerable additional cost with no saving over time to offset it.

Comparisons of running costs are dependant on the difference between gas and electricity prices. For quite a while electricity has been 5-6 times more expensive than gas. Even under the current price cap introduced on 01 Oct it is still in that region (e.g for OVO SVT in my region gas is 4.04p/kWh electricity is 20.59p/kWh.  As said in another thread this ratio could be skewed by market forces or government intervention.

As an annual system COP of 3.0(3kWh output for 1kWh input) is very acceptable for a retrofit heatpump, the ratio of gas/electricity prices will have to change considerably before a heat pump will be cheaper to run than Gas CH.

In the short term, something like 1.5 times the price of gas for installation and running costs might be enough for the target market of these grants.  Just like with EVs, affluent, green-leaning people are prepared to pay a bit more for the warm glow of feeling like they are doing their bit. The rest are going to have to be forced or incentivised.   

Verdigris

They're talking about "up to £5000" now.

It might not be quite such a bargain after all.

Baxter100

As part of my work I see the odd heat pump installation here and there. Today I visited a property which has had an ASHP recently installed (at great taxpayer's expense). The property was semi-detached, 1800s, stone walls (uninsulated), solid floors (uninsulated), pitched roof (limited insulation). Three or four larger radiators were added to the existing heating circuit and the heat pump heated these and the older rads already present.

The contractor who installed the unit was gave little instruction to the homeowners (an elderly couple) except to say to keep the heat pump running 24/7 (it has a buffer vessel) and use the thermostat to control the temperature. Even in October they had already turned the temperature up to 23 degrees C as they liked the house warm. The contractor had also left them some instructions on opening some of the valves on the buffer every three months or so which they hadn't really comprehended.

All in all it felt like a financial disaster waiting to happen.

I fear that this will be a situation replicated millions of times up and down the country over the next few years. People will be having these 'whizzy low carbon heat pumps installed' which 'the BBC said would be just as cheap as a gas boiler.'

Verdigris

23 degrees! I've got my thermostat at 17 degrees. Can't afford to squander cap-price gas.

I fear you are right about heat pumps getting a bad reputation from poorly designed/done installations.

If this grant isn't on condition that it is an MCS certified installation I reckon things will get very bad.

ABrass

Baxter100 said:

As part of my work I see the odd heat pump installation here and there. Today I visited a property which has had an ASHP recently installed (at great taxpayer's expense). The property was semi-detached, 1800s, stone walls (uninsulated), solid floors (uninsulated), pitched roof (limited insulation). Three or four larger radiators were added to the existing heating circuit and the heat pump heated these and the older rads already present.

The contractor who installed the unit was gave little instruction to the homeowners (an elderly couple) except to say to keep the heat pump running 24/7 (it has a buffer vessel) and use the thermostat to control the temperature. Even in October they had already turned the temperature up to 23 degrees C as they liked the house warm. The contractor had also left them some instructions on opening some of the valves on the buffer every three months or so which they hadn't really comprehended.

All in all it felt like a financial disaster waiting to happen.

I fear that this will be a situation replicated millions of times up and down the country over the next few years. People will be having these 'whizzy low carbon heat pumps installed' which 'the BBC said would be just as cheap as a gas boiler.'

How is the tax payer involved? You're not eligible for RHI with poor insulation so there must be a different mechanism in action.

Baxter100

ABrass said:

Baxter100 said:

As part of my work I see the odd heat pump installation here and there. Today I visited a property which has had an ASHP recently installed (at great taxpayer's expense). The property was semi-detached, 1800s, stone walls (uninsulated), solid floors (uninsulated), pitched roof (limited insulation). Three or four larger radiators were added to the existing heating circuit and the heat pump heated these and the older rads already present.

The contractor who installed the unit was gave little instruction to the homeowners (an elderly couple) except to say to keep the heat pump running 24/7 (it has a buffer vessel) and use the thermostat to control the temperature. Even in October they had already turned the temperature up to 23 degrees C as they liked the house warm. The contractor had also left them some instructions on opening some of the valves on the buffer every three months or so which they hadn't really comprehended.

All in all it felt like a financial disaster waiting to happen.

I fear that this will be a situation replicated millions of times up and down the country over the next few years. People will be having these 'whizzy low carbon heat pumps installed' which 'the BBC said would be just as cheap as a gas boiler.'

How is the tax payer involved? You're not eligible for RHI with poor insulation so there must be a different mechanism in action.

The installation was fully funded by the local council.

Also re the RHI, the only requirements are for cavity/loft insulation. No requirement to insulate solid walls, floors, roof rooms, sloping ceilings etc.

Reed_Richards

ABrass said:
How is the tax payer involved? You're not eligible for RHI with poor insulation so there must be a different mechanism in action.

Likewise to get the RHI payment you need to use an MCS accredited installer.  If the contractor referred to was an MCS accredited installer it does not sound as if they should be.

The efficiency of an ASHP depends on the difference between the outside temperature and the temperature of the water circulating round the heating pipes.  If you want to keep your house at 23 C instead of (say) 21 C it will cost you proportionally more but it would be the same proportion with any other type of boiler.    

Baxter100

Reed_Richards said:

ABrass said:
How is the tax payer involved? You're not eligible for RHI with poor insulation so there must be a different mechanism in action.

Likewise to get the RHI payment you need to use an MCS accredited installer.  If the contractor referred to was an MCS accredited installer it does not sound as if they should be.

The efficiency of an ASHP depends on the difference between the outside temperature and the temperature of the water circulating round the heating pipes.  If you want to keep your house at 23 C instead of (say) 21 C it will cost you proportionally more but it would be the same proportion with any other type of boiler.    

That's not true, the efficiency of a heat pump is impacted far more when the temperature differential increases.

The efficiency of a heat pump drops around 10% for each degree increase in temperature differential. So a heat pump which runs at 300% efficiency when the output is 50 degrees C and outside air temp 10 degrees C (40 degrees C difference) will only run at 200% efficiency when the outside air temp is 0 degrees C (50 degrees C difference). So the cost of a unit of heat goes up by 50%. That isn't anything like how a gas boiler operates.

Meatballs

Reed_Richards said:

ABrass said:
How is the tax payer involved? You're not eligible for RHI with poor insulation so there must be a different mechanism in action.

Likewise to get the RHI payment you need to use an MCS accredited installer.  If the contractor referred to was an MCS accredited installer it does not sound as if they should be.

The efficiency of an ASHP depends on the difference between the outside temperature and the temperature of the water circulating round the heating pipes.  If you want to keep your house at 23 C instead of (say) 21 C it will cost you proportionally more but it would be the same proportion with any other type of boiler.    

With all industry schemes and memberships they basically have no teeth and who pays them? The members that sign up to them. Kicking someone off the scheme loses them money. They don't supply any kind of insurance against mis-selling/poor installations.

Eventually after a long string of complaints they might kick someone off a scheme, but not before they've profited from a few government grants and left consumers picking up the pieces. Better off relying on a credit card to protect you! 

Reed_Richards

Baxter100 said:

That's not true, the efficiency of a heat pump is impacted far more when the temperature differential increases.

The efficiency of a heat pump drops around 10% for each degree increase in temperature differential. So a heat pump which runs at 300% efficiency when the output is 50 degrees C and outside air temp 10 degrees C (40 degrees C difference) will only run at 200% efficiency when the outside air temp is 0 degrees C (50 degrees C difference). So the cost of a unit of heat goes up by 50%. That isn't anything like how a gas boiler operates.

You misunderstand (or failed to read) what I wrote.  The important temperature differential that determines the efficiency is the differential between the outside air temperature and the flow water temperature down the heating pipes exactly as you state.  But the influence of room temperature on energy use is the same for all boilers, if you raise the room thermostat setting you will use more energy in the same proportion whatever type of boiler you use.  So if your elderly couple want their thermostat set at 23 C then the fact that they have a heat pump isn't the problem.