ASHP results

[Swwils]

An efficient source is even more important in an poor house. Don't know how that point isn't more clear?

You'd have to live in literally a tent for ON/OFF heating to be the best strategy.

[ALAN/ALAN D]

https://www.express.co.uk/news/uk/17973 ... and-boiler

A Labour peer has slammed the Scottish Government's plans to replace gas boilers with heat pumps, claiming they could expose people to Legionnaire's disease.

Lord Haughey, the owner of a heat pump firm, warned the units experience performance issues when the mercury dips below -5C.

[Stinsy]

https://www.express.co.uk/news/uk/17973 ... and-boiler

A Labour peer has slammed the Scottish Government's plans to replace gas boilers with heat pumps, claiming they could expose people to Legionnaire's disease.

Lord Haughey, the owner of a heat pump firm, warned the units experience performance issues when the mercury dips below -5C.

Why does this misinformation persist?

Heat pumps are very common in Scandinavia where temperatures are much lower!

[AGT]

https://www.bbc.co.uk/news/science-environment-66359093

Sensibly written article.

It makes cense fitting in a properly designed / well insulated new build home. Grey area fitting in an old build with inadequate insulation / windows / radiators / pipe work.

You could say the same for a brand new build with poorly fitted insulation, windows, pipes sized GCH and GCH flow temps.

Article doesn’t mention CoP of heat pumps.
I think it’s a c+ effort article

[Joeboy]

Wasn't the humidity level of UK compared to Scandavia put for forward as a difference maker?

I'd like to hear from folk in Northern Scotland their experiences and grow more awareness of set up issues? I will likely have a crack at one soon (ish).

[Moxi]

Joe I also recall somewhere it being said that the problem was our damp air that caused frosting and hence more defrost cycles than colder but dryer regions.

I would have a DHW ASHP in a flash but the hot water tank would need to be in a shed outside the cottage (where the LPG bottles are currently for the informed amongst us) and no one in the "trade" is interested and I don't thing the wife trusts my plumbing skills that far!

Moxi

[chris_n]

https://www.express.co.uk/news/uk/17973 ... and-boiler

A Labour peer has slammed the Scottish Government's plans to replace gas boilers with heat pumps, claiming they could expose people to Legionnaire's disease.

Lord Haughey, the owner of a heat pump firm, warned the units experience performance issues when the mercury dips below -5C.

Why does this misinformation persist?

Heat pumps are very common in Scandinavia where temperatures are much lower!

We have lots here in Austria too where it is much colder than UK. We did have a mild / damp winter this year but heat pumps dealt with it fine. I was out walking the dog yesterday evening and was passing a new build with a heat pump outside. I couldn't believe how small it was, only about a meter square by maybe 45 - 50 cm deep. This is for a house that in UK would be at least a large 4/5 bed detached (houses here are generally much larger than UK). There is a poor southern aspect on this house (right next to the stream in the valley with other houses above it) so in winter at least solar gain would be minimal. However the construction is very different to the average UK house, the basement is cast solid concrete with XPS insulation and tanking ( we have to be over 1.5m into the ground to prevent frost heave). The walls above basement level are single skin Porotherm blocks https://porothermuk.co.uk/ which hold a lot of air and then 200mm of EPS. Unsure if this one is double or triple glazed but either way the windows will be high performance with good sealing systems. I would also suspect there is a masonary wood stove of some sort for the coldest days.

[Mr Gus]

The fixation on a one off solution, that solves everything rather than the reality & common sense in use of have something to add to the output for the hump months ...does my head in.

[Swwils]

Exactly, they just stick a log on or the space heater in coldest period.

Humidity has an indirect effect on heat pump; for air source, which transfer heat to or from the outside air, high humidity levels can increase the heat capacity of the air, which can improve the heat transfer efficiency of the system. However, high humidity can also lead to more frost accumulation on the outdoor unit's evaporator coils during cold weather, which can decrease efficiency. The heat pump has to periodically go through a "defrost cycle" to remove this frost, consuming additional energy.

So while the absolute humidity (the actual amount of water vapor in the air) might be lower in cold air, the relative humidity (the amount of water vapor in the air compared to the maximum amount the air could hold at that temperature) can still be high if the air is near its dew point.

[Bugtownboy]

https://www.bbc.co.uk/news/science-environment-66359093

Sensibly written article.

It makes cense fitting in a properly designed / well insulated new build home. Grey area fitting in an old build with inadequate insulation / windows / radiators / pipe work.

There’s a whole prog dedicated to HP’s on BBC1 tonight @ 21:00 - presumably on the back of this article.