Heat Pumps - post here.

I'll check

If you have that and the below numbers you can ask Google to give you a heat loss figure.. below are my numbers which ended up close enough to using heatpunk software and what my installer came up with after measuring the house and windows and rads etc..

Did a bit of googling and it suggests if you have the heat loss indicator, Floor area m2, and design temp you can calc the heat pump size.

Heat Loss Indicator

Floor area m2

Temp Difference

Heat pump Size

1.91

121

24

5.54664

These are the numbers for my house based on design temp of 21 degrees at -3.

So it looks like 5kw is probably too small. 6kw might be the right size.. or 7 for a bit of oversize protection? Reassuringly heatpunk and these numbers match

Ok this is what I got back for house as is.

For a 4-bed semi with your numbers, I’d expect installers to land on a 6 kW unit, or possibly a 7 kW if they want extra margin for domestic hot water and cold snaps.

...….................…

And if I upgrade the windows and back doors it's telling me.

a 6–7 kW air‑to‑water heat pump is the sensible range, with the final choice leaning toward 7 kW if you want:
strong DHW,
some margin for worst‑case cold snaps, or
a backup plan for EV charging load later.

7 kW is still a sensible ballpark, but after the window upgrade you may be able to stay at the lower end of the range, around 6 kW, depending on the installer’s room-by-room heat-loss calculation

Not what he would have said about his original Vaillant. My AroTherm Plus 5kW can output 7.5kW

Quick one, loosely Heat Pump related.

Is it better to go the full stop shop route if getting more than one upgrade, or better to do them seperately? I've heard third hand the one stop shop option is more expensive. Any truth in that?

I don't think there is. Used to be tricky naming companies. What part of the country are you in?

There are very few people who will actually have and monitor their heatpump data. So many people have no idea about them and left it totally to an installer to setup, and have never touched it since.

So someone could be delighted with their new warmth in their home, and accept that it costs what it costs to run, blissfully unaware that it could be running 50% cheaper due to badly set settings

Sent you our installers details, based in Nass

R32 is fine for low temp systems. A lot of advice would say go with what your installer knows rather than be set on a make. That said haven't heard much about lg. They don't seem to come up much online. We went with a Grant heatpump and it was the first one our installer did… he was impressed with the price.. his words were 'a heatpump is a heatpump' is your installer solid on heat loss calcs etc? Have you looked at any of their other installations? Your insulation levels sound strong so probably can't go to far wrong

Heatpumpmonitor.org heavily influenced me.

With a min of 30 days, there are over 700 installations in this list, and the Vaillant AroTherm features heavily in the top 100. Next would possibly be the Veissmann.

While the UK heavily dominate the installed locations, systems in other countries are gradually appearing.

What I would be looking for in this list is finding systems which have long continuous runs ( maybe look at data 2 months ago) and specifically look at the LOWEST power consumption point.

Being able to modulate right down is important from an efficiency and economical perspective

My old (2018) Toshiba R134 6kw unit modulates down as low as 120W - verified using a Shelly monitor.

I actually used a spare MyEnergi CT clamp and configured it as "Storage" since that profile is unused.

Apart from seeing it in the MyEnergi app, I was recording it to Home Assistant.

Data is king. You can only prove or disprove something with data (and I mean raw data, not fancy app thingys)

Installation took about 5 days. Id been talking to my installer for months. Ours went live around 18th April. Had Ber following week, result of that two weeks later. Grant paperwork went in about two weeks ago. Had acknowledgement of receipt from seai and follow up saying they were being reviewed and if all in good order would be paid out in next two to three weeks. They do random inspections so if chosen will delay payout until that's done and passed as acceptable. I told my wife it was simple just a swap of gas boiler for the heatpump but it's not quite that 😁 groundworks took a couple of days. Had to dig a trench through the footpath of the house for the run and concrete was nearly 6 inches deep.. I guess they don't build them like they used to on the 80s..

Good job you were so well informed to know what should have been done, to put on a snag list 😜

What do folks generally heat their cylinder to with their heatpump setup? Ours is is at 48 with a hysterisus of 8 so it heats up again at that point.. temp sensor is around middle upper tank..200 litre cylinder..