Air source heat pumps

[Murox]

We have wet underfloor heating/ hot water run by a solid fuel Rayburn. The cottage was built in the 1800s with thick stone walls. We have put in double glazing but apart from that I’m lost where to start.

Worst thing I ever did was to replace a gravity based wet system heated by Rayburn with a pumped system heated by oil. Thankfully we moved house and I was able to install a new Rayburn to a wet system albeit pumped.

 

[Sutty]

We have wet underfloor heating/ hot water run by a solid fuel Rayburn. The cottage was built in the 1800s with thick stone walls. We have put in double glazing but apart from that I’m lost where to start.

We're in a similar position, part of the house dates back to 16th century, "newer" bit is elizabethan, apart from a new extension by us 20 years ago.
Thick stone walls, listed so external insulation definitely out (& we wouldn't). We only installed double glazing a year ago, after having to apply for permission & having to use an expensive, though sympathetic, option.
Internal insulation remains an option as and when we redecorate each room.
A hybrid system might be an option (googled it) but might not be very beneficial!

 

[Penninetrader]

We're in a similar position, part of the house dates back to 16th century, "newer" bit is elizabethan, apart from a new extension by us 20 years ago.
Thick stone walls, listed so external insulation definitely out (& we wouldn't). We only installed double glazing a year ago, after having to apply for permission & having to use an expensive, though sympathetic, option.
Internal insulation remains an option as and when we redecorate each room.
A hybrid system might be an option (googled it) but might not be very beneficial!

Heat loss from solid floors is closely matched to that lost through an uninsulated roof. Insulating floors can be a major job but the final finish can be as the original. Wet underfloor is the best of the best heating system imo and that of my very clever heating engineer Nephew. The flow temp of a gas boiler for underfloor is about 32 degrees and a rad system 60 plus. In the end we all do the best we can given our specific circumstance, one size most definitely does not fit all

 

[enrico]

We're in a similar position, part of the house dates back to 16th century, "newer" bit is elizabethan, apart from a new extension by us 20 years ago.
Thick stone walls, listed so external insulation definitely out (& we wouldn't). We only installed double glazing a year ago, after having to apply for permission & having to use an expensive, though sympathetic, option.
Internal insulation remains an option as and when we redecorate each room.
A hybrid system might be an option (googled it) but might not be very beneficial!

Don't believe the hype that thick walls are bad. They are an excellent insulator and hold the warmth, they work well with a constant heat from a heat pump. The windows doors, ceilings and floors are the bits that need looking at.
Our downstairs walls are a foot thick and don't need insulation but upstairs changed to double brick with no cavity and did need it. Stone walls are good not bad

 

[jenkinsbrynmair]

Our downstairs walls are a foot thick

I wouldn't class that as thick - my shed has sturdier walls!

 

[Penninetrader]

I wouldn't class that as thick - my shed has sturdier walls!

The rear wall of my building is well over 2 ft thick stone then cavity then brick. Constant heat can produce thermal mass but heat pumps are most definitely not in that business due to working at such low temps. They require conditions and supporting infrastructure to achieve anywhere near their claims of benefit.

 

[Penninetrader]

So for those people who need to open windows regularly or are in the habit of "airing" rooms due to damp conditions or to stop condensation in bathrooms, after cooking in kitchens or drying clothes indoors, the message would be "forget it", as the heat loss would be too great?

Reality check in that reply. Heat pumps are great if all conditions are correct plus you are willing to live your life according to your heating system god

 

[enrico]

The rear wall of my building is well over 2 ft thick stone then cavity then brick. Constant heat can produce thermal mass but heat pumps are most definitely not in that business due to working at such low temps. They require conditions and supporting infrastructure to achieve anywhere near their claims of benefit.

But that doesn't mean they won't work. There are so many pros and cons but these were never considered for say gas central heating. You just put it in and turned it up. It didn't matter if the heat went straight through the ceiling as long as you were warm. With ASHP that changes because with a heat pump a loss of heat results in a house which is cold or costing lots to be warm.

 

[jenkinsbrynmair]

Reality check in that reply. Heat pumps are great if all conditions are correct plus you are willing to live your life according to your heating system god

Living in a tupperware box you mean?

 

[sarahcorlett2566]

We built a new house three years ago, so different to older houses but installed an ASHP with underfloor heating downstairs and rads upstairs. The house is insulated to death (I did most of it complete with hazmat suit, swimming goggles and breathing mask) and we have room sensitive controllers downstairs. We also have a log burner. We previously had, in our old house (1930s), oil central heating (all rads) and a log burner.

Our bills are considerably lower than previously and our house is larger. We also have the advantage should we choose, of installing solar panels which would power the ASHP which you couldn’t do with oil unless your tank can also take solar power which some can, I understand. The cost of the ASHP is considerably more than a conventional boiler but we have been able to get a ten year lease purchase for ours which is £125 per year inclusive of annual service and call out costs.

I think as others have said, it very much depends on what sort of house you have and your electricity tariffs. It’s really difficult to compare different houses in different locations and added to that, the changing costs of the different sorts of power source. The initial costs of the ASHP and any renewables is also considerably more and will affect how long you intend to stay at the property.

The main benefit to us is the ability to instal solar power to help reduce the bills. My understanding of the payback for solar where I am is about six years so it is just about worth it for me at the age I am (ie I’ll still be alive when the cost of the solar is paid back) not so great if you don’t intend to live there for that long.

Hope that’s helpful.