Search with Wattson

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!

What’s your ASHP delta T?

Air Source Heat Pumps (ASHPs)

Last Post by Gary 2 years ago

4 Posts

4 Users

0 Reactions

1,528 Views

RSS

TheBinMan

(@thebinman)

Eminent Member Member

Joined: 2 years ago

Posts: 18

Topic starter 13/12/2024 12:06 am [#1940]

Just wondering what delta T folk use with their ASHP?

Did increasing it or decreasing it solve any issues or is it all about efficiency?

Quote

AllyFish

(@allyfish)

Prominent Member Contributor

Joined: 4 years ago

Posts: 520

13/12/2024 8:58 am

Around 5.5degK at design output. Narrows to about 2.4degK on WC low load. Constant flow system so variable deltaT.

ReplyQuote

cathodeRay

(@cathoderay)

Famed Member Moderator

Joined: 4 years ago

Posts: 2947

13/12/2024 2:04 pm

This is of particular interest to me at the moment, as I am trying to work out how my Midea heat pump controls (modulates) its output in response to changing OATs, not whether it uses weather compeensation (it does), but how it implements it in running parameters including the LWT/RWT delta t. The actual LWT/RWT delta t is complicated by the fact that my heat pump almost always (slow) cycles, making the delta t change all the time. However, as it happens, I calculated the mean delta t earlier today for two periods when the OAT was relatively stable over 24 hours, the first mean OAT at 11.40 degrees, the second mean OAT at 6.37 degrees, and the mean delta t values for the two periods were 2.24 and 3.52 degrees.

Neither I nor others who have looked have managed to find a setting in the Midea controller that allows the delta t to be set externally. It appears to come from the heat pumps internal control systems.

Midea 14kW (for now...) ASHP heating both building and DHW

ReplyQuote