DCV keywords with OA-FROM-SYSTEM?

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Has anyone had success using the demand ventilation control keywords with
a central make-up air system using the OA-FROM-SYSTEM keywords?

In the test runs we've done, the OA volume in the "from" system does not
seem to back down with occupancy.



bfountain's picture
Joined: 2011-09-30
Reputation: 201


Good luck, I have tried to get the OA from other system command to work with no success. With that being said I have not tried in v3.63 just v3.61e, the problem may have been fixed. Instead of using OA-from-other-system I usually model a dedicated OA system with an IU-fan coil setup.


Joshua D. Wolfe's picture
Joined: 2011-09-30
Reputation: 0

Does anybody know whether the several issues associated with the use of
OA-FROM-SYSTEM via dummy zones to model DOAS in eQuest have really been
addressed in V 3.63?
In the documentation that comes with V 3.63 I didn't find any definitive
answer, and I see some users keep on having problems with it. It would
be nice to know by sure which are the limitations that still persist to
avoid having to check models in detail to guess what the program is
doing. Could any of the developers give some light on this subject?

*Xavier Garc?a Casals*

Xavier Garcia Casals's picture
Joined: 2011-09-30
Reputation: 0

I can tell you that heat recovery using the OA-FROM-SYSTEM as a central
MAU does still have an issue in version 3.63. The exhaust air stream for
the heat recovery unit is only from the zones directly served by the
OA-FROM-SYSTEM system, not the other systems which draw air from this
system. So, if you are creating a dummy zone for this system, the exhaust
is just from the dummy zone and will be cold (up here in Can)not showing
the true heat recovery.

bfountain's picture
Joined: 2011-09-30
Reputation: 201