To comply with the mandatory sections 6.4.3.4 “Stair and Shaft Vents” and 6.4.3.4.2 “Gravity Hoods, Vents and Ventilators”, according to the climate zone 2, the standard requires that gravity dampers are installed in every outdoor air intake, exhaust hoods, stair and elevator shafts vents.
I’m working in a project that operates 24 hours. The HVAC system designed treats the air before supplied to every floor AHU. Every duct that supplies the air to the AHU has a constant air volume damper. The stairs were designed with pressure sensors and a VFD fan that regulates the volume of air supplied in the stairs according to the outdoor air demand.
I would like to know if the system designed, as described above, complies with the mandatory sections 6.4.3.4 and 6.4.3.4.2, i.e., without gravity dampers. If not, what should we do to comply with these sections?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
December 3, 2012 - 2:39 pm
Sounds like motorized, not gravity, dampers are required under 6.4.3.4.1.
6.4.3.4.2 requires that all outside air intakes and exhaust have motorized dampers (unless exception a applies then gravity dampers are OK).
Sounds like you need to install dampers if they are not included. The reason they are required is that just because it is a 24 hour operation now does not mean that could not easily change.
Marina Andrade
Sustainability Consultancy ServicesCushman & Wakefield
17 thumbs up
December 4, 2012 - 7:39 am
Hi Marcus,
The project is a hospital where it will always operates 24 hours and the exception A is applied (the project is on the zone climate 2). Does that mean the project doesn’t need to have any kind of damper or gravity damper still needs to be installed?
Thanks for your help!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
December 4, 2012 - 9:40 am
The way I read it you are required to have dampers. Either motorized or gravity would comply. I do not see any exceptions that apply.