Forums

Forums
Renewable Heating
Air Source Heat Pum...
Air source heat pum...
 
Notifications
Clear all

Air source heat pump performance

 
Page 41 / 44
Air Source Heat Pumps (ASHPs)
Last Post by batalto 4 years ago
525 Posts
28 Users
418 Reactions
119.2 K Views
RSS
 Derek M
(@derek-m)
Illustrious Member Member
Joined: 5 years ago
Posts: 4427
15/11/2021 10:30 am  

@dant 

Good morning Dan,

I suggest that you download the following manual and confirm that it matches your equipment before we proceed any further.

ThermaV owners manual Monobloc



   
ReplyQuote
 Derek M
(@derek-m)
Illustrious Member Member
Joined: 5 years ago
Posts: 4427
22/11/2021 2:25 pm  

Bad news I'm afraid, my radiators have started to feel warm to the touch. 😥 



   
ReplyQuote
Morgan
 Morgan
(@morgan)
Noble Member Member
Joined: 5 years ago
Posts: 633
22/11/2021 5:56 pm  

@derek-m 

EE8CF195 FECE 4C26 AA18 1EAA81CBBA3A

 


Retrofitted 11.2kw Mitsubishi Ecodan to new radiators commissioned November 2021.
14 x 500w Monocrystalline solar panels.

2 ESS Smile G3 10.1 batteries.
ESS Smile G3 5kw inverter.


   
ReplyQuote
 Derek M
(@derek-m)
Illustrious Member Member
Joined: 5 years ago
Posts: 4427
22/11/2021 7:08 pm  
Posted by: @morgan

@derek-m 

EE8CF195 FECE 4C26 AA18 1EAA81CBBA3A

 

I knew I had heard that somewhere. 😎 



   
ReplyQuote
 Hr_3
(@hr_3)
Eminent Member Member
Joined: 4 years ago
Posts: 16
23/11/2021 7:40 am  

Hi all

Has anyone adjusted their flow temperature as I hear it can produce decent savings on electricity usage?

Also, how often do others ASHP defrost cycle, particularly at night? 



   
👍
2
ReplyQuote
Mars
 Mars
(@editor)
Illustrious Member Admin
Joined: 5 years ago
Posts: 3548
Topic starter 23/11/2021 8:37 am  

@hr_3, we dropped ours from 45C to 40C in November. Our previous COP was 2.7 and it’s now over 3, which is good. Depending on how well insulated you are, and if you’ve got UFH or big rads, you could get away with 35C. 

As for defrosts, we’ll easily do 8-10 when temperatures drop. Humid evenings with temperatures in the 1-3C range are worst for us. Sub-zero temperatures don’t lead to as many defrosts for us because there’s typically less moisture in the air.


Buy a copy of the The Ultimate Guide to Heat Pumps

Subscribe and follow our Homeowners’ Q&A heat pump podcast


   
ReplyQuote



 DanT
(@dant)
Estimable Member Member
Joined: 5 years ago
Posts: 35
23/11/2021 9:42 am  

I asked my installers about switching to weather compensation mode

This was their feedback:

"When we have rads and UFH working together we tend to find using the weather compensation curve is not particularly effective. It can mean that there’s low temperature water in a convective radiator panel which doesn’t provide sufficient output. Our customers with similar set ups are far happier to hit a set flow temp of 50/55 which ensures the panels convect warm air into the rooms.

You can experiment with using the weather compensation mode to see if it suits, but we would recommend just to keep the set flow temperature. Ultimately the thermostat will turn off once it’s hit the set temp so the heat pump will be operating for a shorter period of time at a slightly higher flow temperature and  you’ll find little difference in the ultimate efficiency. You could try adjusting the set back temperature by a few degrees which would mean the temperature in the house is maintained.

Hope that makes sense and do come back to me if there are any further issues re. upstairs heating."

 



   
ReplyQuote
 Kev M
(@kev-m)
Famed Member Member
Joined: 5 years ago
Posts: 1276
23/11/2021 10:47 am  

@dant,

I thought on a dual rad/ufh system the ASHP heated water to a single temperature; the rads got fed this directly and the ufh got it mixed with cold water because it didn't need such a high temperature?  Would your supplier still be saying go for a set 50/55 if you didn't have ufh?  A flow temp of 50 is right at the upper end.  



   
👍
2
ReplyQuote
 witchcraft
(@witchcraft)
Reputable Member Contributor
Joined: 4 years ago
Posts: 91
23/11/2021 11:56 am  

@kev-m The installer (since sacked) who commissioned our rad only installation set flow temps to 55.  I have set it down now to 40 and still the house remains comfortable.



   
ReplyQuote
 Kev M
(@kev-m)
Famed Member Member
Joined: 5 years ago
Posts: 1276
23/11/2021 12:11 pm  

@witchcraft,

I remember seeing an article or video where the installer said they set the radiators at 50C because otherwise the customers complained the heating wasn't working.  



   
👍
2
ReplyQuote
 Hr_3
(@hr_3)
Eminent Member Member
Joined: 4 years ago
Posts: 16
23/11/2021 4:32 pm  
Posted by: @editor

@hr_3, we dropped ours from 45C to 40C in November. Our previous COP was 2.7 and it’s now over 3, which is good. Depending on how well insulated you are, and if you’ve got UFH or big rads, you could get away with 35C. 

As for defrosts, we’ll easily do 8-10 when temperatures drop. Humid evenings with temperatures in the 1-3C range are worst for us. Sub-zero temperatures don’t lead to as many defrosts for us because there’s typically less moisture in the air.

Hi Mars

Thanks, OK I think my ASHP (steibel eltron wpl17) is in line with your cop there (about 2.7)at the moment at 45c flow

I may drop to 35/40c and see outcome.

We have large k2 double convector rads, no ufh but system was installed from scratch, not retrofit so mainly 22mm pipe everywhere. System gets up to 20c no issues which for us is too hot and temperature seems to only drop below 19c after 11-12hours (on the recent colder days at 5c)



   
👍
2
ReplyQuote
Mars
 Mars
(@editor)
Illustrious Member Admin
Joined: 5 years ago
Posts: 3548
Topic starter 23/11/2021 5:49 pm  

@hr_3, give it a bash - you should get a feel for temperature and efficiency within a few days.


Buy a copy of the The Ultimate Guide to Heat Pumps

Subscribe and follow our Homeowners’ Q&A heat pump podcast


   
ReplyQuote



Page 41 / 44
Forum Jump:
Next Topic  
Related Topics
Topic Tags:  ashp (75) , performance (2) , cop (8) ,
Share:

Join Us!

Podcast Picks

Latest Posts

Click to access the login or register cheese
x Powerful Protection for WordPress, from Shield Security
This Site Is Protected By
ShieldPRO →