ASHP & triple glazing

[Ken]

Minus 9 here at the moment. I think we agree it's a good HP stress test?

6.4% of the heat generated in the 24hr window went to defrost cycles. Now we know what minus 9 looks like for defrosting.

There is also a legionella cycle in there so pretty much a worst case scenario? Heat curve set to 0.4 and thermostat set to 19 degs. Outdoor humidity is a dry 45%.

I love charts like that - thanks. Hope you dont mind me asking -

Quite a lot of defrosting going on, at what temp does it more or less stop doing it. Although a COP of 2.66 including HW is good.

At some points i note zero leccy being used why is this? Does it mean you could actually run it with a lower flow temp? (and improve COP) or perhaps the HP is a little on the large size , how big is it.

Have you any idea what COP you would get without the HW?

[Joeboy]

Heat curve is now set at 0.7 and heating to active. System is designed for minus 4.7 or so. It is operating outside that now so it's all a learning curve. Cop of 2.3 with HW cycle and 2.7.with heating. Not sure about the defrost cycles as it will be humidity linked.

[AGT]

Can I suggest a hole saw for access behind the plasterboard, thee cutout can be reused to fill the hole with a small timber fillet passed into the hole and screwed either side of the hole and the hole part placed back in with some filler and a few plasterboard screws

[Joeboy]

Edit 1hr later the vermiculite is dissolving. Use only in dry areas kids!

Vermiculite will hold upto 4x its weight in water apparently!


We have just ordered some bags of perlite. Your idea may be the perfect solution to insulating a small cloakroom that we have in the corner of our property that used to be the old outhouse, 2 external walls, 1 of which is partly a single skin brick only, where the old doorway was blocked in.
It was not internally insulated when the rest of the house was done, nor was the upstairs bathroom presumably because it would have required ripping out the suite, plumbing and tiling.

This particular room, despite an adequately sized radiator, doesnt really get above 16C. But it does have voids behind the plasterboard and no tiling up to the ceiling.

If it works and doesnt cause damp issues great, the room will have been barely touched and not decreased in size.
If it doesnt work and water tracks across then we end up having to rip it all out and do it again, but would have had to do that to insulate the other way anyway.

My cheapo thermometer stuck to the outside of our bedroom window is reading -14C right now. How accurate it is, i dont know but we are in a valley.
Google seems to think its -10C here, met office -9 and xcw -5C.
Our cop was down to 1.86 when i checked last at 3am, and the outside heatpump sensor (in the ASHP housing) was reading -9 at that point . Its still toasty and warm in the house.
You wouldnt have a clue it was even cold out.

Best of fortune in the upgrade. I'm sure you'll notice the difference. I'm off to clean out then caulk the small gap below the plasterboard. It doesn't look good on the thermal camera. This is on the same wall.

[Fintray]

Heat curve is now set at 0.7 and heating to active. System is designed for minus 4.7 or so. It is operating outside that now so it's all a learning curve. Cop of 2.3 with HW cycle and 2.7.with heating. Not sure about the defrost cycles as it will be humidity linked.

Do you feel that you need to put the heat curve up so far, is the house cooling down?
My heat curve is at 0.4 and on weather compensation only, living room still at 24C.

[Joeboy]

Heat curve is now set at 0.7 and heating to active. System is designed for minus 4.7 or so. It is operating outside that now so it's all a learning curve. Cop of 2.3 with HW cycle and 2.7.with heating. Not sure about the defrost cycles as it will be humidity linked.

Do you feel that you need to put the heat curve up so far, is the house cooling down?
My heat curve is at 0.4 and on weather compensation only, living room still at 24C.

It was cold in the big lounge this morning and when I realised it was minus 9 I went for it. I might back it off tomorrow but this is a good way to see other scenarios? Even now the cop is good for temps?

[Joeboy]

Heat curve is now set at 0.7 and heating to active. System is designed for minus 4.7 or so. It is operating outside that now so it's all a learning curve. Cop of 2.3 with HW cycle and 2.7.with heating. Not sure about the defrost cycles as it will be humidity linked.

Do you feel that you need to put the heat curve up so far, is the house cooling down?
My heat curve is at 0.4 and on weather compensation only, living room still at 24C.

It was cold in the big lounge this morning and when I realised it was minus 9 I went for it. I might back it off tomorrow but this is a good way to see other scenarios? Even now the cop is good for temps?

Apols for quote of myself.

I've been running last few days at heatcurve 0.4. It was OK but tbh it wasn't really great. Warm but not cosy. I looked at the circuit setting and it was set to expanded. First time I've been in there so I set it to active.

I'd expect the heat calc to have our homes on a rough parity? We are 200mtrs sqr and a 7kW hp. Maybe there is an impact there? I'll see how fast it gets up to 19 degs room temp then back it off a notch on the curve.

I might also have been caught out since the system is speccd for minus 4.7 and it was minus 9. Or it could be that I've run it too low and last nights plunge caught me out?

[Joeboy]

This is a good read.

https://protonsforbreakfast.wordpress.c ... verheating.

[Fintray]

My calcs were also for -4.7C so identical in that respect, I've just looked at both our graphs for the past 24hrs and when we have both been at -10C the flow temperature here has been 39C whilst yours has been only 33C which is quite low?
It will be interesting to see how well active mode maintains the temperature in the big lounge (assuming the Sensocomfort is in there?).
We are 153M2 with 10kW but a much older/draughtier/exposed house.

[Joeboy]

My calcs were also for -4.7C so identical in that respect, I've just looked at both our graphs for the past 24hrs and when we have both been at -10C the flow temperature here has been 39C whilst yours has been only 33C which is quite low?
It will be interesting to see how well active mode maintains the temperature in the big lounge (assuming the Sensocomfort is in there?).
We are 153M2 with 10kW but a much older/draughtier/exposed house.

Great to see those figures for comparison. I have just dropped the heat curve back to 0.6 which was it's original setting from Bartek. I did this as the 0.7 setting shot the temp up quickly. The active setting should give the unit more scope to do it's own thing? The sensocomfort is in the front lounge as we didn't want the wbs in big lounge to affect the rest of the house reading. This was our readings just before I dropped from 0.7 to 0.6 heat curve. Are you running active or expanded Iain?