Heat Pumps - post here.

I'm seeing the turning off of Weather Compensation more and more is posts of people with high consumption

In my case i experimented a bit, i found even in mild weather lwt of 27 was too low and cycled alot so thats not efficient, during recent cold spell i tried 29deg 24/7 and house was 21/22 and felt warm throughout with minimal cycling. Last year using weather compensation left by installer and various stats on/off in the house i had flow temps of up to 41/42 in minus weather and obviously accompanying high consumption. Think i have found sweet spot of flow temp for my house that is more optimal then weather curve. HP even in cold weather was using 1-1.2kw per hour wheres as it was using up to6kw per hour using on off method and v low cop. Def in cold weather 24/7 low and slow the best approach but anybody i talk to is using stats still to run it like gas boiler.

Sounds like you definitely have a good handle on things. But, even at that low and slow approach, am I right in saying you were using approx. 30kWh/day in the cold days? Just going off 1.2kW per hour x 24 hrs.

You will need a BER assessor who can also do the necessary technical assessment to bring the HLI down to 2.0 or less

What part of the country are you in?

So is it 20kwh per day the heat pump uses in these mild conditions?. In this weather im running midday to 9pm and using approx 14kwh including dhw, house still 21 following morning. In cold weather when using 30kwh, whole house was 21/22, sometimes 23 in kitchen.

That's some difference. I need to read this a few times to see if it helps me.

@graememk did you have to do much remedial work before installing the Heat pump (bigger radiators etc)?

Can I ask what make and model you installed?

I have a Phinix Chinese R290 Heat pump and currently running at 10kwh per day including DHW in a 200m2 house built in the 70s I did a big renovation job with external wall insulation and triple glazed windows. House is only B2 I run a 35 flow on EV tariff and come 5pm I run till about 11pm house is 21 downstairs and 19 upstairs.

In the real cold weather heating from 5pm to 11pm will mean house will be not be at set 20/22 while you are awake. Takes an age to heat house up 2-3deg in cold weather .I was totally against heating 24/7 up until 2 weeks ago when i tried it in the cold snap. Usage went down and comfort and cop went way up. Mild conditions heating at certain times makes more sense imo. Tonight my heating will go off at9om and house will still be 20/21 for breakfast.

@zoom_cool is I think running the way I plan to too - ultimately like a gas or oil boiler, running at higher temps, getting heat in faster, and accepting the lower COP as it heats, but then, at temp, the COP will depend on the heatloss

I have UFH downstairs and Aluminium Rads upstairs on a really cold day it might run during the middle of the day for a hour I run in the EV rate constant at 35 flow you need this for Rads upstairs not sure what the COP is because these heat pumps don't have a Meter to measure COP only consumption. They do give you a chart to have a estimate and would be something like 4.5

Did you import the heat pump or how did you come across this brand?

Also what thickness of wall, floor, etc. insulation have you since the renovation?

2-6 with Energia