Heat Pump Questions

Verdigris

Sterlingtimes said:

What would be required to replace the microbore piping in the house? Would this involve the large scale removal of laminate, carpet and floorboarding carpet, the cutting of new slots in the walls and floors and the complete redecoration of the house?

Yes. It is basically the same as having a new central heating system installed.

Robbo66

Reed_Richards said:

Robbo66 said:

I know someone that rented a house with a heat pump and after about 18 months the Landlord had it changed to oil heating as the heat pump cost a fortune to run and didn't heat the house.

We've all heard stories like that.  If you don't install the right radiators for a lower water temperature then the heat pump won't provide water that is hot enough to adequately heat the house.  But constantly running it at its maximum output in order to try will make it cost a fortune to run.   

Hence why I said that without substantial cost to upgrade the existing system heat pumps cant be retrofitted. 

elsien

Just jumping on board, my outside space is effectively a narrow side return. Then a publicly accessible path. Then a small patch of garden.
How would that work? 

Reed_Richards

Robbo66 said:
Hence why I said that without substantial cost to upgrade the existing system heat pumps cant be retrofitted. 

Except that the cost of the upgrade is small compared to the cost of actual the heat pump.

Reed_Richards

elsien said:

Just jumping on board, my outside space is effectively a narrow side return. Then a publicly accessible path. Then a small patch of garden.
How would that work? 

Heat pump in the garden with pipes run under the publicly accessible path to your house, perhaps?  Heat pumps won't be suitable for every locale, I would have thought.

[Deleted User]

Viessmann is suggesting that heat pumps will last 20 to 25 years whereas others in the industry suggest 10 to 15 years is a reasonable expectation. The latter would put a lot of people off from investing in any expensive heat pump.

QrizB

Reed_Richards said:

elsien said:

Just jumping on board, my outside space is effectively a narrow side return. Then a publicly accessible path. Then a small patch of garden.
How would that work? 

Heat pump in the garden with pipes run under the publicly accessible path to your house, perhaps?  Heat pumps won't be suitable for every locale, I would have thought.

Or heat pump above head height on the side of your home, if you have an upper floor? It's hard to be specific without a site plan or photos and I'm not expecting you to post anything like that.

macman

How much does the radiator area typically have to be increased to make an HP viable in place of a gas boiler? This would be in a 3 b/r semi with non-cavity walls, typical of millions of UK homes. I suspect that most such homes simply do not have the available space to fit substantially larger rads? Also, many such houses no longer have a hot water tank, as they have gone down the combi route. 
With these obstacles, I'm rather hoping that more investment will be put into using hydrogen via the existing gas grid...

Verdigris

macman said:

How much does the radiator area typically have to be increased to make an HP viable in place of a gas boiler? This would be in a 3 b/r semi with non-cavity walls, typical of millions of UK homes. I suspect that most such homes simply do not have the available space to fit substantially larger rads? Also, many such houses no longer have a hot water tank, as they have gone down the combi route. 
With these obstacles, I'm rather hoping that more investment will be put into using hydrogen via the existing gas grid...

It depends on the type of radiator you already have. If it is single panel then replacing with a double panel of the same size might be sufficient. It also depends on whether existing rads have convector fins, or not. Just fitting a taller radiator wouldn't involve much disruption as long as it isn't under a window.

Reed_Richards

macman said:

How much does the radiator area typically have to be increased to make an HP viable in place of a gas boiler? 

Radiator types are:

Single panel (P1/type 10)
Double panel (P2/type 20)
Single panel single convector (K1/type 11)
Double panel single convector (P+/type 21)
Double panel double convector (K2/type 22)
Double panel triple convector (K3/Type 33)

It's the radiator surface area you have to increase, not the area of wall it occupies.  So a double panel replaced by a double panel double convector might well be sufficient.