FW: Setting up ventilation systems in eQUEST [Filed 20 Apr 2010 10:49]

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Katherine Roberts's picture
Joined: 2011-09-30
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Kat,

A few questions to clarify how this system will work:

Is the discharge unit part of either the ventilation AHU or the recirc AHU?
Are you doing any heat recovery with the discharge unit?
Does the FCU have a cooling coil?
Is any part of the system variable volume, or are all four units constant
volume?

Steven

Steven Savich's picture
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Joined: 2011-09-30
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Kat,

eQuest does not allow two air handling systems to be attached to a single
zone, or one AHU to be attached to another, EXCEPT for using another air
handling system as an outside air source. You will need to set the
different zones up with their own AHU, FCU, RACU, etc if you want to
explicitly model the zone fan energy and cooling water use. If there was no
zone level cooling for the fan coil (ie heating only) you could model it as
a PIU system and define that zone as having a fan-powered terminal unit.

This is another of those potential future upgrades to eQuest - the option of
having zone cooling coils in a PIU system to be able to simulate a fan coil
unit dependent on a VAV air handler. I've run into several modeling
situations where this option would have been nice.

It sounds to me like the way to approach this is to model the Ventilation
and discharge fans as part of the same unit with a heat recovery system.
Create a "dummy zone" for the ventilation AHU. As a simplifying assumption,
I think it is reasonable to attach your recirc ahu only to room 1, FCU to
room 2, & RACU to room 3. You can then set OSA source for each of these to
your ventilation AHU.

Anyone else have a good suggestion for a modeling approach?

Steven

Steven Savich's picture
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