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Underfloor heating systems with Sizing:Zone class

asked 2022-08-05 05:41:33 -0500

qirachel's avatar

updated 2022-08-05 10:24:35 -0500

Hi there,

I am working on a project using DesignBuilder/EnergyPlus, where I will need to model an air-to-water heat pump system with underfloor heating and natural ventilation. I checked the example IDF file named: RadLoHydrHeatCoolAutoCondFD provided by EnergyPlus, trying to get an idea how the underfloor systems can be modelled.

I encountered some problems going through the file: I understand the use of the ZoneHVAC:LowTemperatureRadiant object,which defines the underfloor heating/cooling, but I don't get the use of the following ones: Sizing:Zone, DesignSpecification:OutDoorAir, ZoneHVAC:EquipmentList, and ZoneHVAC:EquipmentConnections. In my opinion, the use of these objects is trying to model a system where there is air supplied by and returned to the floor systems like an air-to-air AC instead of a underfloor heating.

I would appreciate it if you could point out the use of these objects in this context :) Thanks in advance!

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seems like the sizing:zone object is used to size the underfloor systems in tems of the tube length, maxinum heating flow rate and cooling flow rate. However, I still don't understand the supply air in the Sizing:Zone object and how it is related to the underfloor systems.

qirachel's avatar qirachel  ( 2022-08-05 10:22:06 -0500 )edit

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answered 2022-08-10 05:54:24 -0500

qirachel's avatar

I figured it out! The sizing:zone is used for autosizing the maximum air airflow at the design supply temperaure at the design day so that the room temperature can be kept within the comfort level required by the room thermostat. Then the virtual supply air flow is converted to the actual maximum hold water flow.

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Asked: 2022-08-05 05:41:33 -0500

Seen: 289 times

Last updated: Aug 10 '22