Zones with different HVAC systems

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Dear All,

I have a building with more than one kind HVAC system. I have the first
floor with VAV system, and the second floor only has ventilation fans
running. So I made all the zones on Second Floor unconditioned, and choose
SUM as air-side HVAC system for second floor. However, the Space Cool of no
VAV for second floor is even higher than that of the whole VAV, which does
not make sense to me.
Do you know how the eQuest calculate Space Cool? Should The VAV energy
consumption be Space Cool+Vent. Fans shown on the simulation output?
Thank you,
Jing

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PhD Candidate, LEED AP BD+C

School of Architecture and Urban Planning
University of Wisconsin-Milwaukee

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SUM system type. The DOE2.2 manuals do not explain the SUM system type very well. From the DOE2.1e manual:

4. System Descriptions
a. Summation of LOADS to PLANT (SUM)
This is actually not a secondary HVAC distribution system, but rather a diagnostic tool, which is used to 1) pass the hourly LOADS program output to the PLANT program without simulating a system, 2) adjust the constant zone temperatures specified in LOADS, 3) simulate the thermostat schedules (but not the equipment), and 4) tabulate energy consumption by ZONE (or group of ZONEs). SUM is not a miscellaneous SYSTEM-TYPE for UNCONDITIONED zones.

UNCONDITIONEO ZONEs should be assigned to another SYSTEM.

Christopher R. Jones, P.Eng.
Technical Specialist
Sustainability & Energy

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T +1 416-644-0252

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Got it! Thank you very much Jones!

Jing

On Wed, Nov 15, 2017 at 1:33 PM Jones, Christopher <
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PhD Candidate, LEED AP BD+C

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Bruce, you mean in eQuest even if a zone needs ventilation only, I still
have to set the zone as conditioned? Then I set the HVAC system as no
heating or cooling. Is that correct?
Thanks,
Jing

PhD Candidate, LEED AP BD+C

School of Architecture and Urban Planning
University of Wisconsin-Milwaukee

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Bruce Easterbrook's picture
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Hi Bruce,

Thanks for your instruction. Your suggestion makes a lot of sense. But I am
wondering, if I make the ventilated zones as conditioned zones,eQuest will
ask for Thermostat, etc. Should I make the Cooling set point very high and
heating setppoint very low to avoid eQuest calculates loads? By your
experience, will that affect my space cool or space heat number?
Thanks,
Jing

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