[Equest-users] DOAS in baseline

[Nick Caton]

Hi Susan!

 

Whether or not a baseline model gets a separate system for a proposed
design featuring a DOAS is dependent on a few things, including how you
decided to approach modeling the DOAS in the proposed model.

 

-          A clarification first:  Type and quantity of baseline systems
is determined first and foremost per Appendix G.3.1.1.  You generally
have either one system per floor or one system per zone, depending on
the system type.  You never start with "one system per proposed system"
except by coincidence.

-          If you use a dummy zone approach (not integrating the DOAS
into the proposed systems), and you have one baseline system serving
only the dummy zone per G.3.1.1 (or its exceptions), and you have
specified the ventilation requirements at that dummy zone (not
indirectly from the actual zones - using OA-FROM-SYSTEM for the proposed
systems)... then you'll end up with a distinct baseline system handling
the ventilation requirements analogous to the proposed DOAS.  

-          In many/most cases (partially dependant on your preferred
strategy for handling DOAS's in your proposed models), you will not have
a dedicated baseline system handling the ventilation air.  That's okay.

 

~Nick

 

 

 

NICK CATON, E.I.T.

PROJECT ENGINEER

Smith & Boucher Engineers

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

www.smithboucher.com 

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Susan F
Sent: Thursday, January 27, 2011 6:11 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] DOAS in baseline

 

This is not exactly an eQUEST question but y'all have been so helpful in
the past so I'm hoping you can help here too.  I'm looking for a little
clarification.  It was my understanding if you had a DOAS system that
heated and cooled the outside air before delivering it to the floor
mechanical room to be combined with return air and further conditioned
by the AHU in your Proposed building that this system would NOT be
modeled separately in the Baseline.  I cannot find anything in 90.1 that
would regulate the DOAS system and I'm not sure how you would model it.
(I understand the dummy zone concept for modeling DOAS but not sure that
would apply to the Baseline.)

Should it be separate system in the Baseline and would it be VAV or
constant volume?  And if it is a separate system what section of 90.1
would you reference for this?


Thanks in advance.

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