Flow temperature & weather compensation. Impact on efficiency
Having had my heat pump for about 18 months I have gradually got to grips with understanding the controls and functions. I'm sure everyone's experience is different as it depends on so many factors including property efficiency, whether lived in all day, wfh, geographic location and more.
The most simple conclusions I came to are that the setup has best efficiency/cost with: Lowest flow temperature possible which is best managed with weather compensation. This requires a different mindset from my previous Oil central heating experiences! Target room temperatures are mostly around 21deg in main living room and kitchen but much cooler in secondary/less used rooms & bedrooms.
I came across a very useful tool that allows comparison of the impact on SCOP (Seasonal Coefficient of Performance) of different flow temperatures.
In my case using the exact model LG Therma V HM161M.U33
I can see the impact of the flow temperature and added benefit of using weather compensation. I am now using both and see that the flow temp is often as low as 30deg! But the house is reaching and holding the target 21deg without difficulty. The house is very old & generally inefficient but with underfloor heating and modern extension. At night I drop the temp just 1 degree (if more it would take a long time to warm up and/or need higher flow temp)
As can be seen in the screenshot the efficiency is around 375% at 35deg with weather compensation down to 200% at 55deg without weather compensation.
A very graphic and clear view of why flow temp should be as low as possible and weather compensation functionality should be used.
Listed Grade 2 building with large modern extension.
LG Therma V 16kw ASHP
Underfloor heating + Rads
8kw pv solar
3 x 8.2kw GivEnergy batteries
1 x GivEnergy Gen1 hybrid 5.0kw inverter
Manual changeover EPS
MG4 EV
Listed Grade 2 building with large modern extension.
LG Therma V 16kw ASHP
Underfloor heating + Rads
8kw pv solar
3 x 8.2kw GivEnergy batteries
1 x GivEnergy Gen1 hybrid 5.0kw inverter
Manual changeover EPS
MG4 EV
@tim441 this is really useful info and a great find. Your experience of converting from oil to ASHP mirrors mine. I'm only 3 months into the journey however. My system design temperature was 50degC but I'm finding with climatic compensation on, a maximum of 42degC flow at 0degC ambient and 30degC flow at 20degC ambient is providing efficient operation. I'm using hugely less energy than I was when I had CH and HW from kerosene, hugely less emissions, and saving around 20% on my fuel bills over the most expensive and energy intensive months. As the days draw longer and the weather warms, the ASHP efficiency and solar PV should really start to kick in and save energy.
-
Warm weather and heat pumps.
5 months ago
-
What happens when the outside temperature exceeds the upper WC point?
6 months ago
-
Savings - using Weather Compensation & Time of Use Tariffs
8 months ago
-
Daikin Octopus installation update - I saw my first defrost. 😍😂
8 months ago
-
Servicing LG Therma V
1 year ago
- 26 Forums
- 2,205 Topics
- 48.6 K Posts
- 52 Online
- 5,864 Members
Join Us!
Podcast Picks
Latest Posts
-
RE: Samsung Heat pump with Yonos Pico circulating pump running all the time
Oooh, are we about to witness a @pirate-rich surgical h...
By Mars , 31 minutes ago
-
RE: Samsung Heat Pump – Can't Activate TW2 Pipe Sensor (for Delta T Control)
If the house loss is much less than the heat pump min o...
By JamesPa , 1 hour ago
-
RE: The Hidden Secret to a Successful Heat Pump: Pipe Size Matters
@editor Agreed. There is another point to be made h...
By JamesPa , 2 hours ago
-
RE: RDSAP10 effect on existing heat pump EPC rating?
Tim, Yes ChatGPT thought I could get another...
By Mike Patrick , 3 hours ago
-
Indeed, all the more so as it is a clear example of rob...
By cathodeRay , 4 hours ago
-
RE: Enabling WiFi: Samsung ASHP on Smart Things App
No problem, @richdorm; glad it helps.
By Majordennisbloodnok , 5 hours ago
-
RE: Help me keep the faith with my air source heat pump installation
If that makes you feel happier then go ahead, but it wo...
By JamesPa , 5 hours ago
-
RE: Testing new controls/monitoring for Midea Clone ASHP
I do already have the same basic setup, all room influe...
By cathodeRay , 6 hours ago
-
RE: IVT Greenline high pressure switch and electrical cassette errors
OK. You dont say whether it is from the feeds to/from ...
By JamesPa , 6 hours ago
-
RE: How can I programme a setback for my Samsung Gen6 8kW heat pump?
Yes, and probably also Adia although the latter has a m...
By JamesPa , 20 hours ago
-
@editor I am all in favour of provocati...
By GrahamF , 1 day ago
-
@editor lol. I wish. They told me to switch everything ...
By bontwoody , 1 day ago
-
RE: How to Understand Wiring Up a Heat Pump
Morning, On top of what everyone else I would deffo loo...
By Grantmethestrength , 1 day ago
-
RE: Sizing a heat pump: Save me from my headache
Got the results back from the one we’re ...
By Mikeatthezoo , 2 days ago
-
RE: Renewables & Heat Pumps in the News
Thanks Lucia. I'll set aside some time to go through th...
By Transparent , 3 days ago
-
RE: Do I just go with the lowest quote for my heat pump?
Seems to be settling better now I'll leave it alone
By Jancold , 3 days ago
-
RE: Bosch CS5800i 5kW - Experience So Far
We do like the exhaust air heat pump as a centralised M...
By Steelbadger , 4 days ago