Forums

Forums
Renewable Heating
Air Source Heat Pum...
Good heat loss calc...
 
Notifications
Clear all

Good heat loss calculator for ASHP with UFH?

 
Page 3 / 3
Air Source Heat Pumps (ASHPs)
Last Post by Anonymous 11 months ago
29 Posts
4 Users
4 Reactions
2,045 Views
RSS
 ash2020
(@ash2020)
Eminent Member Member
Joined: 12 months ago
Posts: 12
Topic starter 14/08/2024 9:12 am  

@johnmo Excellent. I'm going to try and re-instate my Part P electrical qualification which lapsed when I retired.


   
ReplyQuote
Jancold
 Jancold
(@jancold)
Reputable Member Member
Joined: 3 years ago
Posts: 129
15/08/2024 4:46 pm  

@johnmo I revisited the Heatpunk project which I did back in May and put in the data for the floor and ceilings which I had not done and revised the heat loss up to 5070 or 70W/m2.  Does that seem reasonable?

Daikin 6Kw ASHP.
MG4 EV
1926 Semi with loft and wall cavity insulation, all radiator.


   
ReplyQuote
 Anonymous 5011
(@Anonymous 5011)
Noble Member
Joined: 2 years ago
Posts: 563
15/08/2024 6:01 pm  

Posted by: @jancold
↑

@johnmo I revisited the Heatpunk project which I did back in May and put in the data for the floor and ceilings which I had not done and revised the heat loss up to 5070 or 70W/m2.  Does that seem reasonable?

Seems high to me

Take a look here

https://www.heatgeek.com/how-to-size-my-heat-pump-or-boiler-heat-loss-cheat-sheet/

 


   
ReplyQuote
Jancold
 Jancold
(@jancold)
Reputable Member Member
Joined: 3 years ago
Posts: 129
15/08/2024 6:50 pm  

@johnmo Thanks, yes I have that cheat sheet and was a bit surprised it was higher than expected. Maybe I should start the Heatpunk project again. Still awaiting Octopus report promised this week but we will see.

Daikin 6Kw ASHP.
MG4 EV
1926 Semi with loft and wall cavity insulation, all radiator.


   
ReplyQuote
 Anonymous 5011
(@Anonymous 5011)
Noble Member
Joined: 2 years ago
Posts: 563
15/08/2024 7:17 pm  

There is a lot said about perfect sizing of heat pump to heat loss, but if you run open loop, there is flexibility. Our house heat loss at -3 is about 3kW at 7 degs about 1 to 1.5kW, but we have 6kW heat pump. It cycles, at min load and I get about 10 to 12 mins on and off an hour. So doesn't short cycle. We are currently doing cooling it has been a mostly wet day so almost no load required and the heat pump compressor has started 8 times in 18 hrs.

Opposite to what a lot will say - I think you are better to be slightly big on heat demand, your radiators end up bigger, so you can run lower flow temperature, your heat pump has some flexibility, if it gets really cold outside. Get it the other way round, you end up running higher temps and the immersion on if it gets really cold.

No zones (well one) is the best for flexibility, and oversized, you may get a very slight CoP hit when it's mild, but not much, when it's cold it runs fine.

So I wouldn't fret to much, 5kW or 4kW you really should be running a 6kW ASHP. Remember you still need 2 to 3 hrs for DHW each day mid winter 


   
ReplyQuote
Page 3 / 3
Forum Jump:
  Previous Topic
Next Topic  



Share:

Join Us!

RHH Awards

👉 Vote for “Heat Pump of the Year”

👉 Vote for “Best Manufacturer Customer Support”

👉 Nominate “Heat Pump Installation of Year”, “Best New Tech or Innovation” or “Turkey of the Year” here!

Latest Posts