Using formulas in Equest Parent/Child relationships Outside Air

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Hi All,

Does anyone know how to create DOE 2.2 formulas to have Equest calculate
outside air accordingly? I am typically modeling multi-family projects. As
such my models all have MANY single zone split systems (over 400). Per
ASHRAE 62.1, Outside Air = OA-FLOW/PER * NUMBER-OF-PEOPLE + OA-FLOW/AREA *
AREA. However equest only uses the larger of OA-FLOW/PER * NUMBER-OF-PEOPLE
or OA-FLOW/AREA * AREA. I have tried to create a formula and input it into
the field OUTSIDE-AIR-FLOW but I am not very familiar with DOE 2.2 syntax.

AREA is a SPACE property. NUMBER-OF-PEOPLE is a SPACE property.
OUTSIDE-AIR-FLOW, OA-FLOW/PER and OA-FLOW/AREA are all ZONE properties.

How would I write a ZONE formula for OUTSIDE-AIR-FLOW that calls the
corresponding SPACE values for AREA and NUMBER-OF-PEOPLE? I am sure it has
to do with Parent/Child relationships in Equest/DOE 2.2. Is the Space the
parent or child of the zone? Is the space a parent or child of the polygon?

= #L("OA-FLOW/PER")* ?? + #L("OA-FLOW/AREA")*??

Please help.

Joshua W. Chapman PE, LEED AP

Joshua W. Chapman PE, LEED AP
Scot Engineering Inc.
509 Germantown Pike Building 2
Lafayette Hill PA 19444
O1: 215.774.1429

Joshua Chapman's picture
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The eSimForums has a section dedicated to expressions that is pretty
helpful and if you have any further questions I'd recommend making a post
on there. There's a small group of people who seem to respond to questions
in a fairly timely manner over there. Link:
http://www.esimforums.com/equest/viewforum.php?f=70. Specifically, I made
a post on there of the commonly used BDL commands that I use in writing
expressions: http://www.esimforums.com/equest/viewtopic.php?f=70&t=139.

To answer your specific question, to reference a space command from the
zone you'll want to make use of the Local Reference command (#LR). The
question marks in your formula could be replaced by
#LR("SPACE","NUMBER-OF-PEOPLE") and #LR("SPACE","AREA").

Also, it appears you're missing the distribution efficiency factor from
ASHRAE 62.1 in your calculations. Typically this value is 0.8.

Robby Oylear's picture
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