Posted by: @marvinator80

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I was at my in laws up in Stornoway over new year. They have an 10KW (I think) Mitsubishi ASHP and I was encouraged by just how hot the radiators were. The house was really warm and is an older construction with less insulation than mine.

One thing I still can’t quite get my head around is what happens when it hits -10 like it did recently and how the lower temperature compared to traditional boilers can do the hot water for baths and showers. does this mean I should have had the temperature on my oil boiler turned down from 65 to 45 or 50 all along?

The installers reckon 2 days for the removal and installation and a day or 2 to spend entirely on “balancing the system”. 

interesting times ahead.

 

i'm afraid that hot radiators with an ASHP system are not to be celebrated, the hotter the radiators, the faster they are 'burning' your money.

@derek-m yes indeed, though I think my father in law doesn’t care too much because  he has his own wind turbine and solar and are effectively entirely off grid all year round.

it was more good to see in reality that they can actually do that. That an ASHP has the chops, so to speak.

Posted by: @marvinator80

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@derek-m yes indeed, though I think my father in law doesn’t care too much because  he has his own wind turbine and solar and are effectively entirely off grid all year round.

it was more good to see in reality that they can actually do that. That an ASHP has the chops, so to speak.

They do. My ASHP will happily heat all my radiators and hot water to 55 degrees when it's below zero outside. I wouldn't be happy with the bills though.

@marvinator80 

 9000 at 294sqm so the stars do seem to align on this installation

13kW for 294sqm seems tight, based on my experience.

I've a 10kW against 250sqm and its undersized IMO. I make it work, but boy is it working.

@ggw aye, I talked at length with the installers about the sizing and based on the underfloor, construction of the house, heat loss calcs and insulation etc they were very confident 13KW was the right size. 

they also think it will do the upstairs of the garage I’m building which is another 48sqm but I’ve half a mind just to keep that all electric.

Dash and drat. Was supposed to start yesterday but the team have a virus. Now going ahead on the 18th.

I have thought secured a buyer for my old boiler and oil tank. £1200, delighted.

Bad news and good news.

We have about 500litres of oil in our tank, which I'm gravity dispensing to a couple of neighbours below my house c/o a long length of hose they have purchased. They'll be getting the oil at a heavily discounted price *, as it's absolutely no use to me now. I'm going to leave the tank in situ however as it's inobtrusive and not in a convenient location to use the space for anything else.

The installers for my ASHP made sure the old boiler was, ahem, put permanently put out of use. They intentionally stripped and cut the controls wiring out of it. It was a very old Worcester Danesmor 26/32, so was only scrap value anyway. My wife got an extra cupboard in the utility in the space it used to occupy, and I got a utility that did not have the kerosene smell hanging round! 

* That price may be a few months worth of drinks behind the bar in the village pub, but that'll do nicely. 🙂 

@allyfish 

sounds good getting that extra cupboard! We are losing a cupboard in our utility because the cyclinder and stuff are going where the boiler used to be. Have already cut the worktop and cupboard away, it’s just sitting there waiting to be lifted out. 

fully expecting it to look awful and the maybe try to build around it all.

You weren't tempted by the Grant integrated cylinders then? They come at a premium, but look rather smart. https://www.grantuk.com/products/cylinders/quick-recovery-integrated-cylinder/

@allyfish the Afinia radiators look good too.

@allyfish I didn’t know about those, damn! It’s a 250ltr regular Grant cylinder I’m getting.

‘Twas the night before heat pump, and all through the house, not a creature was stirring, not even a ….dog.