Forums

Forums
Renewable Heating
Air Source Heat Pum...
How to balance a po...
 
Notifications
Clear all

How to balance a post buffer tank circulation pump?

 
Air Source Heat Pumps (ASHPs)
Last Post by Dunlorn 11 months ago
4 Posts
4 Users
1 Reactions
675 Views
RSS
 Potatoman
(@potatoman)
Estimable Member Member
Joined: 2 years ago
Posts: 57
Topic starter 19/12/2024 9:54 pm  

Hi, has anybody managed to balance the circulating pump in the ASHP with the post buffer tank circulating pump, and if so how did you manage it. Thanks


This topic was modified 11 months ago by Mars

   
Quote
Transparent
 Transparent
(@transparent)
Illustrious Member Moderator
Joined: 4 years ago
Posts: 2701
20/12/2024 12:10 pm  

@potatoman  - follow what @ashp-bobba is describing to @netdonkey over on this other topic.

He's addressing a very similar issue!


Save energy... recycle electrons!


   
ReplyQuote
Mars
 Mars
(@editor)
Illustrious Member Admin
Joined: 5 years ago
Posts: 3687
20/12/2024 3:08 pm  

@potatoman, to balance a buffer system effectively, both flow rates and flow temperatures on the primary and secondary sides must align perfectly.

Modern air source heat pumps modulate their flow temperature based on the controller’s set point, and many also adjust flow rates to maintain a specific Delta T (temperature difference) on the primary side of the buffer. However, the secondary side is less straightforward.

The secondary pump may regulate flow using pressure control methods, but it cannot directly maintain Delta T due to factors like zone valves or TRVs adjusting flow dynamically. This means the flow to individual emitters isn’t always consistent, which can affect balancing.

Emitters are sized for specific mean flow and return temperatures, and changes in flow rate can shift the Delta T, altering radiator output. Without precise control or measurement of both flow and temperature on the secondary side, true balancing isn’t achievable.

While buffers aren’t inherently bad, they’re often less effective with modern inverter-driven compressors, which perform best in direct systems. Buffers work better with fixed-compressor units, where control is based on return temperatures rather than flow temperatures.

For your specific question, balancing would require synchronising both pumps through careful calibration and possibly additional controls or sensors on the secondary side. However, this level of precision is rarely implemented in standard installations.


Get a copy of The Ultimate Guide to Heat Pumps

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


   
ReplyQuote
Dunlorn
 Dunlorn
(@dunlorn)
Estimable Member Member
Joined: 3 years ago
Posts: 79
20/12/2024 4:21 pm  

@potatoman This post https://renewableheatinghub.co.uk/forums/postid/38331 may also help you.


2 x 12kW Samsung Gen6 ASHP, 5.6kW solar PV ground mounted c/w 10kWh Puredrive battery & Solis inverter.


   
👍
1
ReplyQuote
Forum Jump:
  Previous Topic
Next Topic  



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 →