ASHP in cooling mode

[Melvin Gregory]

I've an AHU with heat exchanger for warm air and DX coil for cool air.  The DX coil has never been used and I would like to replace this DX coil with chilled water coil so a new ASHP can occasionally supply cool air through the AHU .  My CW coil fabricator wants to know the potential flow and return temperatures from the ASHP when it's in cooling mode.  Is there a guide that will tell me that information for various ASHPs?   Thanks     Mel G

[JohnMo]

I have seen 15 degs as flow temp for ufh, and there will be a 4 to 7 return temp drop, based on your flow rates.

 

Just looked at the dreams ASHP and the default setting is 12 degs.

 

Don't think you want it too cool otherwise you get condensation issues.

[Melvin Gregory]

I won't be cooling UF circuits and the cooling coil is in AHU with ductwork to each room.  I just plan to have cool air to bedrooms during hot summers. Probably going to use Viessmann ASHP, about 10KW, for heating and hot water. These can also be used for cooling and I will just T off ASHP F&R with 3 port valves which will be controlled by some kind of switching system.  I'm wondering what the temperature range of these ASHPs is in the cooling mode?  Is it adjustable and what's ideal temperature for use in AHU with chilled water coil?  The AHU also has a heat exchanger coil and drip tray for condensate. Originally had a DX coil which I have removed and intend to replace with chilled water coil.

[joth]

For those following along at home, a glossary maybe useful

AHU = Air handling unit

ASHP = Air source heat pump :)

CW coil = chilled water coil.

DX coil = Direct expansion coil, for heat exchange to/from a refrigerant circuit.

[FCU = Fan Coil Unit]

 

 

FWIW, my ecodan ASHP can go down to 5°C flow temp, I set it to 8°C and my FCU only has a couple degrees drop across it, I've clearly not yet got the water flow speed and sizing very will calibrated for the HP.