(eQuest Users) Summer heating in a VAV system

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I am having issues with VAV systems in eQuest. This is a reoccurring problem for me. I am getting large amounts of heating during the summer. I suspect this is due to reheat at the VAV terminals. I've tried everything I can think of to eliminate this. I have lowered my minimum VAV flow rates, lowered my summer heating setpoint temp to 55, locked out my boilers based on higher outside air temps. All these changes eliminated my summer heating. But they also shot my unmet heating hours way up. Does anyone have any other suggestions on how to correct this?

Thank you,

Scott Tomlinson, PE, LEED-AP

Tomlinson, Scott's picture
Joined: 2011-09-30
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Hi Scott,

I would look through the load part of your model for the answer. For
instance I notice that many of you spaces have no equipment loads, including
your mechanical room (!?!). Put a small w/sf in each space. Your occupancy
loads are also small compared to what other building types have. Also, look
at your schedules to see if you agree with the default. After that if you
are still having a problem, let us know.



cmg750's picture
Joined: 2010-10-05
Reputation: 0


I would apply different thermostat schedules to some of your spaces. You
have three mechanical spaces, two bathrooms and a work space out of 13
total spaces on the system. These spaces are probably not intended to be
heated and cooled within the same narrow range as the offices etc. Also,
you have entered the supply cfm for the system but not for the zones. It
would not take much effort to add design cfm to the zones to see how it
changes things. I was going to suggest that you make your bathroom walls
"air walls" since that is where you are exhausting from - air is being
transferred from adjacent spaces. However, you already have all your
interior walls set to air walls. I'm guessing most of those should be
changed to "standard".


William Bishop, PE, BEMP, LEED(r) AP

Bishop, Bill2's picture
Joined: 2011-09-30
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