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

[Steven Savich]

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


-----Original Message-----
From: Katherine Roberts [mailto:Katherine.Roberts at arup.com] 
Sent: Tuesday, April 20, 2010 8:25 AM
To: ssavich at systemswestengineers.com
Subject: RE: [Equest-users] FW: Setting up ventilation systems in eQUEST
[Filed 20 Apr 2010 10:49]

Hi Steven,

The discharge unit is a separate AHU but serves the same space as its
accompanying recirc AHU.
The fresh air injection unit and the discharge unit have an energy
reclaim coils.
The fan coil unit has chilled water cooling.
All systems are variable volume.

Kat

-----Original Message-----
From: Steven Savich [mailto:ssavich at systemswestengineers.com] 
Sent: 20 April 2010 16:14
To: Katherine Roberts
Cc: equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] FW: Setting up ventilation systems in eQUEST
[Filed 20 Apr 2010 10:49]

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 

-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of
Katherine Roberts
Sent: Tuesday, April 20, 2010 5:46 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] FW: Setting up ventilation systems in eQUEST
[Filed 20 Apr 2010 10:49]


> Hi,
> 
> I'm new to eQUEST and am trying to get up to speed with how eQUEST 
> sets up ventilation systems - the attached sketch shows an example 
> system that I am trying to set up in eQUEST:
> 
>  <<Example Ventilation Schematic.pdf>> It shows a recirculation AHU 
> (with a fresh air supply) which supplies air to different rooms via 
> fan coil units (FCU), room air conditioning units (RACU) and 
> pressurised floor plenums. Do I need to model the individual FCUs, 
> RACUs, and discharge units as separate systems or do I just set up one

> AHU and attach the different rooms to it? What I don't understand is 
> how eQUEST takes into account different fan speeds/sizes for the 
> various room units if I'm assuming they're all attached to one AHU?
> 
> Any suggestions would be greatly appreciated.
> 
> Thanks
> 
> Kat
> 
> 
> 

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