Exhaust air routes

2 posts / 0 new
Last post


The building floor that I am presently modeling has several conditioned
zones and two unconditioned zones. The conditioned zones are various
offices. The unconditioned zones are restrooms and an electrical room. The
conditioned zones exhaust to each other and, ultimately, to the
unconditioned zones via hallways, doorways, etc. The unconditioned zones
exhaust to the outside (via fans).
How can I explain to eQuest that, for example, conditioned zone A
exhausts to conditioned zone B? Also, how can I explain to eQuest that
conditioned zone D exhausts X% to the electrical room (and thus to outdoor
exhaust fans) and Y% to conditioned zone C?
In case it matters, the ceiling is open and the return ductwork
terminates in one spot. Accordingly, even return air must flow among the
conditioned zones.
Thanks, as always, for your helpful replies.

Lars Fetzek, EI

Lars Fetzek's picture
Joined: 2011-09-30
Reputation: 0


Not sure if this is what you're looking to do. I haven't tried this for
a chain of more than two zones, but you can specify the outside air
coming from a particular zone in eQUEST using the "OA-FROM-SYSTEM"
keyword. You have to be careful with this to define the OA system before
the system it feeds (i.e. if system 1 has an OA-FROM system2, but system
2 has not been defined yet in the INP file, you will get an error.

Another thing to watch out for is that when you use the OA-FROM, I don't
think eQUEST calculates the cooling effect of the ventilation air. You
might have to trick the program into accounting for that using an
internal energy source (process) with a negative value. This is easier
with a constant volume OA supply, but if you really want to you could
write a schedule for the VAV supply - it's pretty tricky.

Vikram Sami, LEED AP

Vikram Sami's picture
Joined: 2011-09-30
Reputation: 0