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radiant surface for both floor heating and cooling

asked 2022-08-11 04:10:19 -0600

qirachel's avatar

updated 2022-08-11 07:44:11 -0600

Hi there, I am working on a building with air-to-water heat pump systems and underfloor heating and cooling using radiant surface.

I first defined a HP with hot water loop for floor heating (see attached diagram), and now I am wondering if I can use the same loop and HP for cooling as well (which means an air to water reversible heat pump), or I need to design another cooling water loop with a new HP system. Thanks in advance.

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answered 2022-08-15 06:23:26 -0600

qirachel's avatar

conclusion: there is the EIR-formulated water-to-water heat pump model: HeatPump:WaterToWater:EIR:Heating and Cooling: 1) can be used for GSHP for heating and cooling together; 2) operate with maximum flow(constant flow); 3) now they are working on adapting the model for air source heat pump with constant flow (it will always request its full design flow from the plant), with a future addition planned to make it respond to outlet setpoint in order to vary the flow request; 4) There is not currently a central plant air-to-water heat pump in EnergyPlus:

solution: Use an air-cooled chiller to supply the chilled water loop and a heat pump water-heater to supply the hot water loop. Use availability managers on the plant loops to prevent them from operating at the same time.

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@qirachel your 4) comment is incorrect, there is a central plant air-to-water heat pump object in EnergyPlus. It's called HeatPump:PlantLoop:EIR:Cooling (and :Heating), and it can have its condenser type input set to "AirSource" or "WaterSource". This was added to EnergyPlus in v9.3, so perhaps DesignBuilder hasn't added it as an option yet.

Aaron Boranian's avatar Aaron Boranian  ( 2022-08-15 09:22:17 -0600 )edit

You can read more about his in a post here (history of your suggested solution being used before this capability was added to EnergyPlus) and here (DesignBuilder support team member recommends how to model a similar ASHP system).

Aaron Boranian's avatar Aaron Boranian  ( 2022-08-15 09:25:43 -0600 )edit

@Aaron Boranian Thanks! It is of great help! I will check it out

qirachel's avatar qirachel  ( 2022-08-15 09:49:33 -0600 )edit

Design Builder did a demo/training on topics related to this last week (8/10/22), On the recording its about ~20min into the video it adds a radiant heating and cooling system to a zone group; but it was using a traditional boiler/chiller to do so. The last example in that webinar use a HP Water heater system (goal was demo'ing the EMS/BMS controls for carbon emissions) - BUT it might be possible to combine these examples to get the needed radiant heat/cooling system from a HP source.

dradair's avatar dradair  ( 2022-08-16 08:44:03 -0600 )edit

@dradair Thanks for sharing the tutorial videos! it is really helpful

qirachel's avatar qirachel  ( 2022-08-16 09:00:45 -0600 )edit

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Asked: 2022-08-11 04:10:19 -0600

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Last updated: Aug 15 '22