I'm trying to model a waterside economizer in eQUEST and I'm getting
curious results. The building energy usage goes up. There is no real
change to the space cooling load, but the fan energy doubles and there
is a 25% increase in pump energy (expected). It looks like it's turning
on the equipment for the economizer, but its running the chiller as
well.
What am I missing here?
Vikram Sami, LEED AP
Never mind - I found the documentation in Vol 6.
Sorry about that
Vikram Sami, LEED AP
If you are using the newer version of eQUEST (3.62 or 3.63) then the water
side economizer is modelled as a new chiller of type "water economizer".
It models it as a heat exchanger between the condenser loop and the
chilled water loop and automatically runs this "chiller" when ambient
conditions allow. (in contrast to one of my earlier posts which stated
you needed an equipment control -- you don't). There is some requirement
for 1 condenser loop per water side chiller so check the new features
documentation for the water-side economizer chiller.
If you are using the air-side keywords for a water side economizer (the
"old" way), you need to set up a strainer cycle keyword on the cooling
tower and it adds new coils to the air stream (which could cause the
increased fan energy) -- I think -- I haven't done it this way so you'd
really need to check the docs.
I have had what I think is good success using the water side economizer
chiller in 3.63.
Best of luck,
Brian
Can you please take me off the email user list. I tried to online
several times, but it is not stopping the emails.
Thanks.
Alan Vestal, PE, LEED(r) AP