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Heating pump air to water

asked 2016-05-16 11:40:10 -0600

João Rodrigues's avatar

I need to use a centralized heating pump air to water on my project to heat and cool a radiant floor. However, I only find HP water to water on the HVAC systems. I have HP air to water but only as a zone object.

Is there any way to have a heating pump air to water system?

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answered 2016-05-25 06:28:53 -0600

Urado's avatar

The air-source heat pump is not yet available in EnergyPlus and thus in OpenStudio. You can follow its integration here.

The WaterHeater:HeatPump is a zonal object but it can be used with external air source, so it may be still interesting depending on your case.

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Thanks for the answer! But, how can I link this water heater, as a zone object, to my radiante floors? Do I need to create a HP for each thermal zone?

João Rodrigues's avatar João Rodrigues  ( 2016-05-25 11:52:08 -0600 )edit

You can have a plant heat pump water heater or just an outdoor HPWH. See example file HeatPumpWaterHeater.idf and search for

  PlantHeatPumpWaterHeater,!- Name

  OutdoorHeatPumpWaterHeater,  !- Name
rraustad's avatar rraustad  ( 2016-05-25 12:17:05 -0600 )edit

You don't need to create several HP. You can add it to your plant loop in the HVAC Systems tab and the linked it to your radiant floor. However, you have to use the water tank as explained here.

Urado's avatar Urado  ( 2016-05-26 02:41:18 -0600 )edit

answered 2016-05-27 11:05:18 -0600

João Rodrigues's avatar

updated 2016-05-27 11:07:07 -0600

I saw your advice Urado, and it worked... However, when I run the simulation (after solving some errors) the results are blank, is like if my system is offline...

As you can see, theres no Heating or Cooling loads, what am I doing wrong?

I have my system represented as the following pictures

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The OS report may be wrong. Did you check the results with Output:Variable ?

Urado's avatar Urado  ( 2016-05-30 03:16:02 -0600 )edit

Yes. I have the following output variables on: Zone Air System Sensible Cooling Energy; Zone Air System Sensible Heating Energy; Zone Air Temperature; Zone Electric Equipment Electric Energy / Power; Zone Outdoor Air Drybulb Temperature; Zone Thermostat Air Temperature; Zone Thermostat Cooling Setpoint Temperature; Zone Thermostat Heating Setpoint Temperature; Zone Total Internal Total Heating Energy; But, for my case Zone Air Temperature should be enought to give me those values right?

João Rodrigues's avatar João Rodrigues  ( 2016-05-30 07:57:18 -0600 )edit

Yes, you should have a different Zone Air Temperature with and without your radiant floor, if your model is correct. I would add the nodes flow and temperature to check HVAC systems. Maybe a sizing problem...

Urado's avatar Urado  ( 2016-05-30 08:45:22 -0600 )edit

Hi Urado, I forgot to tell, it was a problem with the thermostat, we need to change the thermostat direct on the radiant systems, because they are not affected by the zone thermostat.

João Rodrigues's avatar João Rodrigues  ( 2016-07-26 05:51:21 -0600 )edit

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Asked: 2016-05-16 11:40:10 -0600

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Last updated: May 27 '16