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Intake-Exhaust separation on packaged unit


Registered User
Oct 3, 2022
New York
A client has made a comment on a design to provide additional ductwork on a packaged rooftop unit to ensure the intake and exhaust are 10 feet apart. Currently the packaged unit has factory installed hoods which are on adjacent corners.

I'm aware of the 10-foot requirement between environmental air exhausts and mechanical air intakes under NYC Mechanical Code 501.3.1 (3) but it seems pretty implausible that literally every packaged rooftop unit in NYC was specified and installed in violation of code, and I want to say I was given a reason/exception for this situation but I can not find it. Is there a code citation or similar that justifies having intake and exhaust hoods on the same unit within the 10-foot (and 3-foot vertical) separation?
I've always gone with they are both part of a listed manufactured appliance, which are required to be installed per manufacturer's instructions. The appliance was listed that way. As long as they are not modified its OK.

Now if the fresh air is ducted away to get clearance to a flue exhaust From another nearby unit, all bets are off and the 10' separation is required from both unit exhausts, because the factory location of the fresh air has been changed.
IMC 401.4 #3 allows ventilation air intake within 10' of the exhaust if the exhaust is >=3' above the intake. I've seen accessories for RTUs that provide for this vertical separation. I took a look at the NYC version and this is the same.