Different operation schedules for ventilation system

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Dear All,

Is it allowable ,based on the ASHRAE appendix G and LEED NC, for exhaust
fans in the non conditioned areas to operate with a schedule different from
the baseline schedule? I have a jet and exhaust fans for non conditioned
area , but those fans will operate in accordance to a programmable timer
(on-off).

Masri_new

Mohammad Almasri's picture
Joined: 2011-09-30
Reputation: 400

Schedules generally should be identical between baseline and proposed -
if you modify one you should modify the other in the same fashion.

What is your justification to do something different? 90.1 has
provisions to alter schedules when necessary to demonstrate nonstandard
energy efficiency measures - see Table G3.1.4.

NICK CATON, E.I.T.

Nick-Caton's picture
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Joined: 2011-09-30
Reputation: 805

Any fan in a non-conditioned space is considered a process load and must be modeled identically in both cases. This applies to parking garage fans, unconditioned warehouse ventilation fans, mechanical/electrical exhaust, etc. Like Nick indicated, taking credit for nonstandard efficiency measures requires the modeler to demonstrate that the measure is nonstandard. Many U.S. codes require some sort of automatic control measure for these types of fans, so it?s very difficult to claim that a timer, thermostat, or carbon monoxide sensor is nonstandard. Outside the U.S. may be a different case, but I would be prepared to provide the relevant section of the local code.

DAKOTA KELLEY

Dakota Kelley's picture
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Joined: 2011-09-30
Reputation: 1