People Saying Heat Pumps are Rubbish - Are They?

matelodave

heres another one - https://www.bing.com/videos/riverview/relatedvideo?q=michael+de+podesta&mid=87D1A8190462A0E5716187D1A8190462A0E57161&FORM=VIRE

Spies

Do your own heat loss calcs on heatpunk, mine came out surprisingly close to Octopus' survey

benson1980

grumpypensioner said:

MeteredOut said:

grumpypensioner said:

I wonder why so many forumites are so defensive about their installation of heat pump systems? Every new technology has problems as well as great benefits. Why don't we list the pros and cons honestly to help future purchasers choose? Opinions?

Its quite similar to the "EV debate". There's a lot of misinformation that those who have EVs (and in this case, have heat pumps) are able to debunk.

In the case of Heat Pumps, the starting position I hear is that any house can be converted to work with a heat pump with running costs lower than or equivalent to a gas boiler and that any negative reports we see are due to badly spec'd/installed/configured systems.

I'm not convinced it is a simple as that.

What can never be defined without more detailed investigation is what work is needed to get any individual house "heat pump ready" so that running costs are lower or equivalent to a gas boiler.

eg, I have a house with a large floor space with water underfloor heating throughout downstairs and traditional radiators upstairs, but fairly poorly insulated, all powered from a 40kW gas boiler. I know it should be possible to get a Heat Pump working, but there's a lot of work to do to get it there - my (admittedly fairly rudimentary to date) look into this makes me believe simply swapping out the gas boiler for a heat pump would never suffice.

You make a very good point. I have been unable to find out the actual cost of someone's installation - not just a quote. From researching the subject I am not sure that saving money is the main reason for installing a system. It is perhaps a way of helping reduce personal fossil fuel usage by passing the buck onto the national grid. It would need a large unit to replace your gas boiler only to achieve equivalent running costs with a loss of capital - refute that if people can.
I found a bit of a solution, I purchase a standalone air conditioner unit to supplement my old Baxi gas boiler, with a new Wessex 1.47kw 12000 BTU unit from ToolStation (over 200% efficiency) which cost me under £400 installed (needs a standard 10cm wall air duct and drain pipes and just plugs into a 13 amp socket). I switch it on in cold weather and it warms the whole house when needed so that I can reduce the load and temperature of the gas central heating system (and I still have lovely hot water for showers), difficult to quantify but my energy bill has significantly reduced for minimal outlay. I really think that a large single replacement installation is not the solution, apply technology where it fits and compromise.

That setup certainly does sound like a compromise. Why does your boiler not meet your heating requirements and how can it be more cost effective to run an electric heat source at 200% efficiency? The only way it could be is if you are using it to heat one room, shutting doors of rooms you aren’t using much, and switching off your central heating completely I’m guessing? 

Quite commonly people are opting to install ashps when their current gas or oil boilers are due replacement so it is small extra outlay, or in some cases actually less. And they also enjoy hot water for showers.

QrizB

benson1980 said:

grumpypensioner said:

I found a bit of a solution, I purchase a standalone air conditioner unit to supplement my old Baxi gas boiler, with a new Wessex 1.47kw 12000 BTU unit from ToolStation (over 200% efficiency) which cost me under £400 installed (needs a standard 10cm wall air duct and drain pipes and just plugs into a 13 amp socket)

That setup certainly does sound like a compromise. Why does your boiler not meet your heating requirements and how can it be more cost effective to run an electric heat source at 200% efficiency? The only way it could be is if you are using it to heat one room, shutting doors of rooms you aren’t using much, and switching off your central heating completely I’m guessing? 

There's a place for those one-hose portable heat pumps (I've got one myself that only cools) but they all have the same limitation, namely that the (cold/hot) air that they vent when (heating/cooling) comes from inside the house and is air that you've previously (heated/cooled). And it's replaced by (cold/hot) air from outside.

This limits their COP considerably, compared to a two hose, ducted or split system where the inside air stays inside and the outside air, outside.

grumpypensioner

QrizB said:

benson1980 said:

grumpypensioner said:

I found a bit of a solution, I purchase a standalone air conditioner unit to supplement my old Baxi gas boiler, with a new Wessex 1.47kw 12000 BTU unit from ToolStation (over 200% efficiency) which cost me under £400 installed (needs a standard 10cm wall air duct and drain pipes and just plugs into a 13 amp socket)

That setup certainly does sound like a compromise. Why does your boiler not meet your heating requirements and how can it be more cost effective to run an electric heat source at 200% efficiency? The only way it could be is if you are using it to heat one room, shutting doors of rooms you aren’t using much, and switching off your central heating completely I’m guessing? 

There's a place for those one-hose portable heat pumps (I've got one myself that only cools) but they all have the same limitation, namely that the (cold/hot) air that they vent when (heating/cooling) comes from inside the house and is air that you've previously (heated/cooled). And it's replaced by (cold/hot) air from outside.

This limits their COP considerably, compared to a two hose, ducted or split system where the inside air stays inside and the outside air, outside.

QrizB said:

benson1980 said:

grumpypensioner said:

I found a bit of a solution, I purchase a standalone air conditioner unit to supplement my old Baxi gas boiler, with a new Wessex 1.47kw 12000 BTU unit from ToolStation (over 200% efficiency) which cost me under £400 installed (needs a standard 10cm wall air duct and drain pipes and just plugs into a 13 amp socket)

That setup certainly does sound like a compromise. Why does your boiler not meet your heating requirements and how can it be more cost effective to run an electric heat source at 200% efficiency? The only way it could be is if you are using it to heat one room, shutting doors of rooms you aren’t using much, and switching off your central heating completely I’m guessing? 

There's a place for those one-hose portable heat pumps (I've got one myself that only cools) but they all have the same limitation, namely that the (cold/hot) air that they vent when (heating/cooling) comes from inside the house and is air that you've previously (heated/cooled). And it's replaced by (cold/hot) air from outside.

This limits their COP considerably, compared to a two hose, ducted or split system where the inside air stays inside and the outside air, outside.

Yup I expect your are all right, but it don't half work well! My old gas back boiler (with a front fire) is over 40 years old, is self maintained because it is so simple and hasn't cost me any maintenance (I just give it a blast with compressed air and a vacuum). It runs two downstairs radiators and provides excellent hot water at 55ºC and a warm drying cupboard. It is switched off from 6.30 pm to 6.30am (we retire early and don't have to get up early for work!). We have a 35 year old Daikin external heat pump (also zero maintenance) which keeps the upstairs warm - and cool when needed. I purchase the additional Wessex unit for the front room primarily for cooling because my wife suffers the heat (and cold fluctuations) but I found it to be perfect for boosting the temperature during cold periods first thing in the morning before the radiators had time to work, it only takes an hour or two while we get up. Then thanks to my smart energy meter and courtesy of BG I was able to track and compare usage over the past years which showed a significant drop annually but it could be just the weather! Because it allowed me to reduce the temperature and thus load on my main boiler. The point being is that I have had minimal capital outlay for an improvement, and we are very comfortable so it is a good compromise. Instead of spending £10,000 (?) on a complete new system so my ISA's interest pays for any inefficiencies and I don't have any maintenance costs.....
I think key factors may be the speed of response, it is powerful and circulates air around the house, and to quote an old tv clip is very on and offable!

MeteredOut

Nick_Dr1 said:

MeteredOut said:

In the case of Heat Pumps, the starting position I hear is that any house can be converted to work with a heat pump with running costs lower than or equivalent to a gas boiler and that any negative reports we see are due to badly spec'd/installed/configured systems.

I'm not convinced it is a simple as that.

What can never be defined without more detailed investigation is what work is needed to get any individual house "heat pump ready" so that running costs are lower or equivalent to a gas boiler.

eg, I have a house with a large floor space with water underfloor heating throughout downstairs and traditional radiators upstairs, but fairly poorly insulated, all powered from a 40kW gas boiler. I know it should be possible to get a Heat Pump working, but there's a lot of work to do to get it there - my (admittedly fairly rudimentary to date) look into this makes me believe simply swapping out the gas boiler for a heat pump would never suffice.

It is as simple as that. The system just needs to be designed such that heat in > heat out. This works for any heat source. Its just more nuanced for heatpumps as they don't crank out large amounts of heat in a short period like an oversized gas boiler.
A heatpump system needs to be designed, by someone who understands what they are doing. This includes understanding heat loss, heat transfer of radiators and heat flow rate though pipes. And that's it.
Get it wrong though and there's nowhere to go. With a gas boiler you normally have excess heat capability to allow for incompetent heat flow design.
What this means is that "standard" houses can have a "standard" design. Unusual houses need bespoke design by someone who knows what they are doing. So it is all about the spec.

What about a hot water tank? The only place one could go in my property is a loft space (low height as we have a high ceilings) and that would either require major work to run new pipes, or lengthy runs if existing pipes were to be used (ie, the run from where the boiler is and a heat pump would go to the loft space and back would be quite legthy).

Though maybe I will get someone out to see what they suggest might be possible. The boiler is 15+ years old now and had its first leak this year (simple parts replacement) so its probably best I plan ahead.

FreeBear

MeteredOut said:

Nick_Dr1 said:

MeteredOut said:

In the case of Heat Pumps, the starting position I hear is that any house can be converted to work with a heat pump with running costs lower than or equivalent to a gas boiler and that any negative reports we see are due to badly spec'd/installed/configured systems.

I'm not convinced it is a simple as that.

What can never be defined without more detailed investigation is what work is needed to get any individual house "heat pump ready" so that running costs are lower or equivalent to a gas boiler.

eg, I have a house with a large floor space with water underfloor heating throughout downstairs and traditional radiators upstairs, but fairly poorly insulated, all powered from a 40kW gas boiler. I know it should be possible to get a Heat Pump working, but there's a lot of work to do to get it there - my (admittedly fairly rudimentary to date) look into this makes me believe simply swapping out the gas boiler for a heat pump would never suffice.

It is as simple as that. The system just needs to be designed such that heat in > heat out. This works for any heat source. Its just more nuanced for heatpumps as they don't crank out large amounts of heat in a short period like an oversized gas boiler.
A heatpump system needs to be designed, by someone who understands what they are doing. This includes understanding heat loss, heat transfer of radiators and heat flow rate though pipes. And that's it.
Get it wrong though and there's nowhere to go. With a gas boiler you normally have excess heat capability to allow for incompetent heat flow design.
What this means is that "standard" houses can have a "standard" design. Unusual houses need bespoke design by someone who knows what they are doing. So it is all about the spec.

What about a hot water tank? The only place one could go in my property is a loft space (low height as we have a high ceilings) and that would either require major work to run new pipes, or lengthy runs if existing pipes were to be used (ie, the run from where the boiler is and a heat pump would go to the loft space and back would be quite legthy).

Though maybe I will get someone out to see what they suggest might be possible. The boiler is 15+ years old now and had its first leak this year (simple parts replacement) so its probably best I plan ahead.

A few solutions spring to mind.

A horizontally mounted tank up in the loft. Downside is getting a tank up there, and ensuring there is sufficient structural support (but that would apply to a vertical tank also).

Construct a well insulated shed just outside the house to house the DHW tank plus ancillaries - Extra expense, and may not be practical. But I do know of at least one installation that went that route.

A Heat Geek mini store - Small enough to fit inside a kitchen cupboard, although total DHW supply from one charge may not be sufficient for your needs if you go for a smaller unit.

Finally, if you don't need copious quantities of hot water and just have a shower, instant water heaters at the point of use could be used.

MeteredOut

FreeBear said:

MeteredOut said:

Nick_Dr1 said:

MeteredOut said:

In the case of Heat Pumps, the starting position I hear is that any house can be converted to work with a heat pump with running costs lower than or equivalent to a gas boiler and that any negative reports we see are due to badly spec'd/installed/configured systems.

I'm not convinced it is a simple as that.

What can never be defined without more detailed investigation is what work is needed to get any individual house "heat pump ready" so that running costs are lower or equivalent to a gas boiler.

eg, I have a house with a large floor space with water underfloor heating throughout downstairs and traditional radiators upstairs, but fairly poorly insulated, all powered from a 40kW gas boiler. I know it should be possible to get a Heat Pump working, but there's a lot of work to do to get it there - my (admittedly fairly rudimentary to date) look into this makes me believe simply swapping out the gas boiler for a heat pump would never suffice.

It is as simple as that. The system just needs to be designed such that heat in > heat out. This works for any heat source. Its just more nuanced for heatpumps as they don't crank out large amounts of heat in a short period like an oversized gas boiler.
A heatpump system needs to be designed, by someone who understands what they are doing. This includes understanding heat loss, heat transfer of radiators and heat flow rate though pipes. And that's it.
Get it wrong though and there's nowhere to go. With a gas boiler you normally have excess heat capability to allow for incompetent heat flow design.
What this means is that "standard" houses can have a "standard" design. Unusual houses need bespoke design by someone who knows what they are doing. So it is all about the spec.

What about a hot water tank? The only place one could go in my property is a loft space (low height as we have a high ceilings) and that would either require major work to run new pipes, or lengthy runs if existing pipes were to be used (ie, the run from where the boiler is and a heat pump would go to the loft space and back would be quite legthy).

Though maybe I will get someone out to see what they suggest might be possible. The boiler is 15+ years old now and had its first leak this year (simple parts replacement) so its probably best I plan ahead.

A few solutions spring to mind.

A horizontally mounted tank up in the loft. Downside is getting a tank up there, and ensuring there is sufficient structural support (but that would apply to a vertical tank also).

Construct a well insulated shed just outside the house to house the DHW tank plus ancillaries - Extra expense, and may not be practical. But I do know of at least one installation that went that route.

A Heat Geek mini store - Small enough to fit inside a kitchen cupboard, although total DHW supply from one charge may not be sufficient for your needs if you go for a smaller unit.

Finally, if you don't need copious quantities of hot water and just have a shower, instant water heaters at the point of use could be used.

As I thought (and said), it's not as simple as the "swap out boiler for heat pump, upgrade radiators" some suggest.

We have 4 bathrooms and although its unusual for more than 2 showers to be running at one time, it can happen when we have visitors. The existing 40kW boiler just about copes, but I have to pre-emptively increase the HW temperature from the low setting I usually have it at.

FreeBear

MeteredOut said:

FreeBear said:

MeteredOut said:

Nick_Dr1 said:

MeteredOut said:

In the case of Heat Pumps, the starting position I hear is that any house can be converted to work with a heat pump with running costs lower than or equivalent to a gas boiler and that any negative reports we see are due to badly spec'd/installed/configured systems.

I'm not convinced it is a simple as that.

What can never be defined without more detailed investigation is what work is needed to get any individual house "heat pump ready" so that running costs are lower or equivalent to a gas boiler.

eg, I have a house with a large floor space with water underfloor heating throughout downstairs and traditional radiators upstairs, but fairly poorly insulated, all powered from a 40kW gas boiler. I know it should be possible to get a Heat Pump working, but there's a lot of work to do to get it there - my (admittedly fairly rudimentary to date) look into this makes me believe simply swapping out the gas boiler for a heat pump would never suffice.

It is as simple as that. The system just needs to be designed such that heat in > heat out. This works for any heat source. Its just more nuanced for heatpumps as they don't crank out large amounts of heat in a short period like an oversized gas boiler.
A heatpump system needs to be designed, by someone who understands what they are doing. This includes understanding heat loss, heat transfer of radiators and heat flow rate though pipes. And that's it.
Get it wrong though and there's nowhere to go. With a gas boiler you normally have excess heat capability to allow for incompetent heat flow design.
What this means is that "standard" houses can have a "standard" design. Unusual houses need bespoke design by someone who knows what they are doing. So it is all about the spec.

What about a hot water tank? The only place one could go in my property is a loft space (low height as we have a high ceilings) and that would either require major work to run new pipes, or lengthy runs if existing pipes were to be used (ie, the run from where the boiler is and a heat pump would go to the loft space and back would be quite legthy).

Though maybe I will get someone out to see what they suggest might be possible. The boiler is 15+ years old now and had its first leak this year (simple parts replacement) so its probably best I plan ahead.

A few solutions spring to mind.

A horizontally mounted tank up in the loft. Downside is getting a tank up there, and ensuring there is sufficient structural support (but that would apply to a vertical tank also).

Construct a well insulated shed just outside the house to house the DHW tank plus ancillaries - Extra expense, and may not be practical. But I do know of at least one installation that went that route.

A Heat Geek mini store - Small enough to fit inside a kitchen cupboard, although total DHW supply from one charge may not be sufficient for your needs if you go for a smaller unit.

Finally, if you don't need copious quantities of hot water and just have a shower, instant water heaters at the point of use could be used.

We have 4 bathrooms and although its unusual for more than 2 showers to be running at one time, it can happen when we have visitors. The existing 40kW boiler just about copes, but I have to pre-emptively increase the HW temperature from the low setting I usually have it at.

With four bathrooms, do you not have a DHW tank already ?

MeteredOut

FreeBear said:

MeteredOut said:

FreeBear said:

MeteredOut said:

Nick_Dr1 said:

MeteredOut said:

In the case of Heat Pumps, the starting position I hear is that any house can be converted to work with a heat pump with running costs lower than or equivalent to a gas boiler and that any negative reports we see are due to badly spec'd/installed/configured systems.

I'm not convinced it is a simple as that.

What can never be defined without more detailed investigation is what work is needed to get any individual house "heat pump ready" so that running costs are lower or equivalent to a gas boiler.

eg, I have a house with a large floor space with water underfloor heating throughout downstairs and traditional radiators upstairs, but fairly poorly insulated, all powered from a 40kW gas boiler. I know it should be possible to get a Heat Pump working, but there's a lot of work to do to get it there - my (admittedly fairly rudimentary to date) look into this makes me believe simply swapping out the gas boiler for a heat pump would never suffice.

It is as simple as that. The system just needs to be designed such that heat in > heat out. This works for any heat source. Its just more nuanced for heatpumps as they don't crank out large amounts of heat in a short period like an oversized gas boiler.
A heatpump system needs to be designed, by someone who understands what they are doing. This includes understanding heat loss, heat transfer of radiators and heat flow rate though pipes. And that's it.
Get it wrong though and there's nowhere to go. With a gas boiler you normally have excess heat capability to allow for incompetent heat flow design.
What this means is that "standard" houses can have a "standard" design. Unusual houses need bespoke design by someone who knows what they are doing. So it is all about the spec.

What about a hot water tank? The only place one could go in my property is a loft space (low height as we have a high ceilings) and that would either require major work to run new pipes, or lengthy runs if existing pipes were to be used (ie, the run from where the boiler is and a heat pump would go to the loft space and back would be quite legthy).

Though maybe I will get someone out to see what they suggest might be possible. The boiler is 15+ years old now and had its first leak this year (simple parts replacement) so its probably best I plan ahead.

A few solutions spring to mind.

A horizontally mounted tank up in the loft. Downside is getting a tank up there, and ensuring there is sufficient structural support (but that would apply to a vertical tank also).

Construct a well insulated shed just outside the house to house the DHW tank plus ancillaries - Extra expense, and may not be practical. But I do know of at least one installation that went that route.

A Heat Geek mini store - Small enough to fit inside a kitchen cupboard, although total DHW supply from one charge may not be sufficient for your needs if you go for a smaller unit.

Finally, if you don't need copious quantities of hot water and just have a shower, instant water heaters at the point of use could be used.

We have 4 bathrooms and although its unusual for more than 2 showers to be running at one time, it can happen when we have visitors. The existing 40kW boiler just about copes, but I have to pre-emptively increase the HW temperature from the low setting I usually have it at.

With four bathrooms, do you not have a DHW tank already ?

No, so it might struggle with simultaneous 4 showers today, but its not caused us a problem. We rarely have more than 2 showers at any one time., but if needed, ramping up the HW temperature at the boiler and lowering the shower thermostats so the mix is less HW and more CW just about makes it viable.