It would be great to get a copy of NFPA 96! Is there a PDF Download available from the folks on Batterymarch Park?
Back in "the day" circa 1980's - late 1990's; when I used to actually work...,
the Ventilation sub assembly to be shut down / not shut down on detection of Combustion were - at best, decided by some sort of Daily Lottery; possibly per the roll of Dice...
Conflicting requests / specifications between the MEP Teams -vs- the Officials of a given Agency, resulted in tremendous ExcedrinŽ Headaches for all involved.
For Hoods, sometimes the MUA was shut down and the EF stayed on; other times the EF was shut down and the MUA stayed on.
Sometimes both MUA and EF were shut down, and other times both stayed on!
There were a few occasions where no one actually cared what the shut down sequence was!
Still get woozy thinking about those installs!
Per the Electrical Designs & Engineering of Refrigeration related Systems; where Flammable, Toxic or Highly Toxic Refrigerants (i.e.: NH3 {Ammonia Systems}) are involved, I have a 10 Page document which Specifies the basic requirements and regulations per the CFC (California Fire Code - CCR Title 24, Part 9).
Very minimal Data, but its something.
A somewhat related issue existed back then - and has reared its ugly head again recently... Placement of Duct Smoke Detectors in Plenums for HVAC Package Units.
Conflicts pertaining to which Duct should be monitored - Supply Air or Return Air - spawned some rather interesting Designs & Addenda!
There have been many instances, where only the Supply Air Plenums were specified to be monitored.
Even after initiating RFI Blitzkriegs, the "Commands" were to monitor Supply Air Plenums only.
(BTW, the Duct Smokes were installed no farther than 60" from the Package Unit, and - of course - had the typical 1/2" EMT Monitoring Tube running through the center of the Duct, perpendicular to the Air flow)
It makes sense (at least to me) to monitor the Return Air Plenums for Combustion (Smoke), not the Supply Air Plenums themselves.
Economizers and OA Fans bring Unconditioned Outside Air in to the Package Unit / Supply Air.
The minimum PPM required to trigger an Alarm Status will be offset by the "Thinned Out Smoke" in the Supply Plenums.
Having both monitored makes sense too. This covers both Supply and Return Air and also monitors the Package Unit for catastrophic failure.
Open for comments.
-- Scott (EE)
