Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
6

Air Source Heat Pump Curves

asked 10 years ago

Gilles CR's avatar

updated 10 years ago

keb's avatar

I seeking for an excel spreadsheet that calculate biquadratic equation coefficients given an array of air temperature, water conditions, capaicities and COPs. This is to input into the Energyplus curve table.

Preview: (hide)

Comments

What type of ASHP are you interested in? Commercial? Residential? Traditional split-system? Mini-split?

Eric Wilson's avatar Eric Wilson  ( 10 years ago )
1

I would be interested in Commercial type Air to water for a commercial building.

Gilles CR's avatar Gilles CR  ( 10 years ago )
1

I am looking for this as well...I have a Multistack air-cooled heat pump chiller.

Anna Osborne Brannon's avatar Anna Osborne Brannon  ( 9 years ago )

3 Answers

Sort by » oldest newest most voted
4

answered 10 years ago

updated 10 years ago

In your EnergyPlus install folder, \PreProcess\HVACCurveFitTool\CurveFitTool.xlsm Even though it is intended for air-to-air, you should be able to adjust the inputs to match water temperatures on either side.

Preview: (hide)
link

Comments

1

While I haven't looked at that spreadsheet, I would think air-to-water heat pumps can see a much wider range of return water temperatures (up to 120ºF or higher), compared to the relatively constant return air temperature that air-to-air heat pumps see (around room temperature, perhaps with some outdoor air mixed in). I would be cautious about using air-to-air curves for an air-to-water heat pump.

Eric Wilson's avatar Eric Wilson  ( 10 years ago )
1

The range of temperatures expected during the simulation (air or water) can be entered in the curve fit tool such that the performance curve coefficients accurately represent performance.

rraustad's avatar rraustad  ( 9 years ago )

Is there an example that shows how to "adjust the inputs to match water temperatures on either side"?

Gio's avatar Gio  ( 8 years ago )

No example that I'm aware of.

MJWitte's avatar MJWitte  ( 8 years ago )

I think there is no adjustement to do. The names "Outdoor air T ( C)" "Leaving condenser water T ( C)" are just labels for this proposed example. You have to read them as "Indipendent variables" and so they can be outdoor air temperature and water outlet temperature without any change.

Gio's avatar Gio  ( 8 years ago )
2

answered 10 years ago

keb's avatar

See the following link from EnergyPlus helpdesk website: http://energyplus.helpserve.com/Knowl...

There is a zip file with excel spreadsheets and pdf instructions.

Preview: (hide)
link

Comments

That link appears to be for WatertoWater or WatertoAir heat pumps. Did you mean to link to a different page for AirtoAir heat pumps?

Eric Wilson's avatar Eric Wilson  ( 10 years ago )

I'm think Gilles meant to say water to air. :)

keb's avatar keb  ( 10 years ago )

It's actually air to water. Does this still apply?

Gilles CR's avatar Gilles CR  ( 10 years ago )

We might be having a semantics problem. Describe the equipment; what function is being performed?

keb's avatar keb  ( 10 years ago )

Heat is taken from or rejected to the air from the source side and the heat pump is connected to an hydronic circuit on the building side.

Gilles CR's avatar Gilles CR  ( 10 years ago )
1

answered Oct 30

In the more recent energy plus versions, there are now example files that include biquadratic curves for air to water heat pump.

C:\EnergyPlusV24-2-0\ExampleFiles\PlantLoopHeatPump_EIR_LargeOffice-2-AWHP-AuxBoiler-Pri-Sec-4PipeBeam.idf

Preview: (hide)
link

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Training Workshops

Careers

Question Tools

1 follower

Stats

Asked: 10 years ago

Seen: 1,412 times

Last updated: Oct 30 '24