100% OA VAV system control question

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Hi Chris,

CO2 sensor based control can be called as DCV. Minimum-cfm-schedules and
minimum-oa-fraction based OA control is for the outside air being partially
served for sometime to the zones.
If you have to model DCV at the system level then you will be required to
use that DCV CO2 based option in the outside air tab of the system.
DCV is used for the areas with more than 50 square meter area and more
than 40 occupancy in 100 square meter floor area. This is mentioned in the
ASHRAE 90.1-2007.
I have done DCV for some projects by the DCV CO2 sensor based option for
areas especially like classrooms and canteens.
So if in a small area there is higher transit occupancy then we are
required to have DCV as per ASHRAE-90.1.


---------- Forwarded message ----------
From: "Jones, Christopher via Equest-users" <
equest-users at lists.onebuilding.org>
To: "equest-users at lists.onebuilding.org" Cc:
Date: Mon, 3 Apr 2017 15:05:28 +0000
Subject: [Equest-users] 100% OA VAV system control question

The school project I am working on has a 100% outdoor air VAV system. The
VAV box flow is controlled by CO2 sensors. I am not sure if this can be
directly modeled in eQuest? In the past I have modeled this kind of system
by specifying min-cfm-schedules in each zone and specifying a
min-oa-fraction of 1 at the system. I have never tried using the CO2 DCV

[image: cid:image001.jpg at 01D2A6E9.840756F0]

*Christopher R. Jones*, P.Eng.

Technical Specialist

*WSP Canada Inc.*
2300 Yonge Street, Suite 2300

Toronto, ON M4P 1E4 Canada
T +1 416-644-0252


*Please consider the environment before printing...*

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