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Availability for two different systems: VRF and radiant floors

asked 2018-07-25 09:30:50 -0600

My project has a room served by a radiant slab for heating, and a VRF terminal for cooling. How can I make it so that each system only works for their respective load ?

As a related question, in case the radiant floor is not enough to handle the heating load, the VRF in heating mode should handle the differential. The radiant system should be sized enough for this not to be the case, but the control sequence allows it.

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answered 2018-07-25 09:51:04 -0600

E+ 8.9.0 recently added a new field to the ZoneHVAC:EquipmentList, that is Load Distribution Scheme.

This field isn't exposed in OpenStudio (neither the OS App nor the SDK), so it will just default to SequentialLoad, which happens to be exactly what you need it to be.

You need to properly define the equipment priorities though: you want the radiant to be 1 and the VRF to be 2.

In the OS Application, the priority is defined by the order in which you added the equipment. In the SDK (ie in a script or a measure), it's easy to change the priority for a given equipment.

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I think the Zone HVAC:EquipmentList has been added to the SDK here.

I'm really not that familiar with measure writing. Does that mean we could write a measure that could change the order of equipment and Load distribution Scheme? Has anyone tried it yet?

Frederic Leveille's avatar Frederic Leveille  ( 2020-02-20 07:47:20 -0600 )edit

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Asked: 2018-07-25 09:30:50 -0600

Seen: 287 times

Last updated: Jul 25 '18