Renewable Heating Hub Heat Pump Forums

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

Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!

How to balance a post buffer tank circulation pump?

 
Air Source Heat Pumps (ASHPs)
Last Post by Dunlorn 2 years ago
4 Posts
4 Users
1 Reactions
1,946 Views
RSS
 Potatoman
(@potatoman)
Trusted Member Member
Joined: 3 years ago
Posts: 57
Topic starter 19/12/2024 9:54 pm   [#1959]

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



   
Quote
Transparent
 Transparent
(@transparent)
Illustrious Member Moderator
Joined: 5 years ago
Posts: 3463
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: 6 years ago
Posts: 4973
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.


Dad’s Outside with the Heat Pump Again
He wanted to save the planet. His family just wanted him to come inside.
Get the book → · Free UK shipping
The Ultimate Guide to Heat Pumps · Britain’s Heat Pump Shitshow
Heat Pumps Explained · From Zero to Heat Pump Hero · Bodge Buster
From Zero to Heat Pump Hero and Bodge Buster are rewritten and updated for 2027.
New to heat pumps? Heat Pump Fundamentals course — 50% off with INTRO50.


   
ReplyQuote
Dunlorn
 Dunlorn
(@dunlorn)
Estimable Member Member
Joined: 4 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:

SPONSORS

Join Us!

Installer Finder

Degrees of Separation

Latest Posts

SPONSORS

Members Online

Click to access the login or register cheese
Protected By
Shield Security PRO