Hi there,
An engineer reached out to me about contact switches documented on operable windows that are empowered to shut down the associated FCU in dormitory bedrooms when the window is open. This functionality allows the FCU to run at something like 50F for freeze protection, but stops the FCU from running concurrent to when the window is open which would waste energy.
My engineer tells me ASHRAE90.1 has may indirect references to avoiding simultaneous heating and cooling, but they have not been able to find a specific reference pertaining to operable windows and/or window contact switches.
Is anyone aware of any specific requirements either in LEED's Minimum/Optimize Energy Performance language, ASHRAE90.1, or other energy codes that relate to this relationship between FCU operations and operable windows?
Thanks in advance,
Aley
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
August 24, 2022 - 7:47 pm
I am not aware of any requirements along these lines. If you want to claim energy savings for this strategy it should be submitted as an exceptional calculation. You will need to define the baseline, which I assume would be without these switches, but also based on some kind of assumptions about how often the windows are opened. This assumption should be justified based on some sort of study of dorm window use. Let us know how you make out.