ASHP - Terraced house

waqasahmed

So whilst you can't plonk one outside the house fairly easily, say you've got a cellar in said terraced house 

Could the ASHP go in the cellar instead? Would the COP also be slightly "better" in such a situation too given it isn't actually exposed to the outside temperature but rather the internal temperature of the house? 

Grandad2b

The heat pump works by taking heat from the source air. Put it in the cellar and you have a few cubic metres of air which will cool very quickly and then what?

Screwdriva

waqasahmed said:

Could the ASHP go in the cellar instead? Would the COP also be slightly "better" in such a situation too given it isn't actually exposed to the outside temperature but rather the internal temperature of the house? 

ASHP won't work. They need the immediate area around them to be clear of obstruction. That said, a Ground Source heat pump would work, as the main collector/ exchanger coils remain external to the property and only the pumping unit/ compressor remains indoors

Coastalwatch

waqasahmed said:

So whilst you can't plonk one outside the house fairly easily, say you've got a cellar in said terraced house 

Could the ASHP go in the cellar instead? Would the COP also be slightly "better" in such a situation too given it isn't actually exposed to the outside temperature but rather the internal temperature of the house? 

Don't know about the COP being any better, but, if you can vent externally it may at least approach manufacturers spec. While not specifically located in a cellar I believe the matter of locating in a loft has been discussed elsewhere although again incorporating external vents.

tacpot12

You can get ducted ASHPs, although they tend to be smaller, so are just used for domestic hot water and not for heating.  I'm not aware of any in the UK that are suitable for heating, but they may become available. 

A Ground Source Heat Pump might be viable if you have a long garden. Slinky coils need about 50m² of outdoor space per kw if they are installed horizontally, and I would expect you would need at leat 8kw for your house, so your back garden needs to be at least 400m² (or 1.5 tennis courts if that helps visualise the size needed). There is an option to have the slinky coils installed vertically, but getting the machinery that can trench deep enought (at least 2m) into a back garden is going to be very difficult, unless there is unrestricted access from the rear, e.g. from a farmer's field.

This is an interesting video of someone's experience of installing an ASHP into a terraced house: https://youtu.be/m2-_x0XZUSM

waqasahmed

tacpot12 said:

You can get ducted ASHPs, although they tend to be smaller, so are just used for domestic hot water and not for heating.  I'm not aware of any in the UK that are suitable for heating, but they may become available. 

A Ground Source Heat Pump might be viable if you have a long garden. Slinky coils need about 50m² of outdoor space per kw if they are installed horizontally, and I would expect you would need at leat 8kw for your house, so your back garden needs to be at least 400m² (or 1.5 tennis courts if that helps visualise the size needed). There is an option to have the slinky coils installed vertically, but getting the machinery that can trench deep enought (at least 2m) into a back garden is going to be very difficult, unless there is unrestricted access from the rear, e.g. from a farmer's field.

This is an interesting video of someone's experience of installing an ASHP into a terraced house: https://youtu.be/m2-_x0XZUSM

Unfortunately for my parents they don't have a "long garden" either

So I guess they might have to stick with the not so green hydrogen boilers  

waqasahmed

Grandad2b said:

The heat pump works by taking heat from the source air. Put it in the cellar and you have a few cubic metres of air which will cool very quickly and then what?

I mean there are windows too but I get what you're saying ie: air flow is seriously restricted 

QrizB

waqasahmed said:

Unfortunately for my parents they don't have a "long garden" either

Is there a reason why they can't have one in a conventional spot, above ground and to the front or rear of their house?

So I guess they might have to stick with the not so green hydrogen boilers  

Depending on how Government policy works out, hydrogen boilers might be more expensive to run than direct electrical heating. We won't know for a decade or so.

waqasahmed

QrizB said:

waqasahmed said:

Unfortunately for my parents they don't have a "long garden" either

Is there a reason why they can't have one in a conventional spot, above ground and to the front or rear of their house?

So I guess they might have to stick with the not so green hydrogen boilers  

Depending on how Government policy works out, hydrogen boilers might be more expensive to run than direct electrical heating. We won't know for a decade or so.

So 

There's a "back" and a "front"

The front side is connected directly to the pavement 
The back door connects to a very very small concrete "garden" before then connecting to pavement

I imagine most people with terraced houses have a similar situation. The odd one here and there will have a much bigger space where they can indeed pop an ASHP 

QrizB

waqasahmed said:

So 
There's a "back" and a "front"
The front side is connected directly to the pavement 
The back door connects to a very very small concrete "garden" before then connecting to pavement

I can see how that would be a problem, yes.

waqasahmed said:

I imagine most people with terraced houses have a similar situation.

I wouldn't like to guess as to "most", but where I grew up many terraces still had fair-sized back gardens.

Here's a screenshot from Google Maps for some 19th century terraces in a Cornish mining town:

waqasahmed

QrizB said:

waqasahmed said:

So 
There's a "back" and a "front"
The front side is connected directly to the pavement 
The back door connects to a very very small concrete "garden" before then connecting to pavement

I can see how that would be a problem, yes.

waqasahmed said:

I imagine most people with terraced houses have a similar situation.

I wouldn't like to guess as to "most", but where I grew up many terraces still had fair-sized back gardens.

Here's a screenshot from Google Maps for some 19th century terraces in a Cornish mining town:

Thanks. Looking further it seems that the cellar would require venting to the outside should you pop an ASHP in there

So it is "doable"