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Elevation of ignition source

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klarenbeek

Silver Member
Joined
Jan 28, 2010
Messages
421
Location
Sioux Falls, SD
Commercial building with underground parking, with the boiler room separated from the garage by a single door. The design of the boilers is such that all sources of ignition are at least 18" above the floor. The circulation pumps (12 of them) are all on housekeeping pads, but the motors, etc. are less than 18" above the primary floor. Here's the relevant code section from the 2021 IMC:

304.3 Elevation of ignition source.
Equipment and appliances having an ignition source and located in hazardous locations and public garages, private garages, repair garages, automotive motor fuel-dispensing facilities and parking garages shall be elevated such that the source of ignition is not less than 18 inches (457 mm) above the floor surface on which the equipment or appliance rests. For the purpose of this section, rooms or spaces that are not part of the living space of a dwelling unit and that communicate directly with a private garage through openings shall be considered to be part of the private garage.
Exception: Elevation of the ignition source is not required for appliances that are listed as flammable vapor ignition resistant.

304.3.1 Parking garages.
Connection of a parking garage with any room in which there is a fuel-fired appliance shall be by means of a vestibule providing a two-doorway separation, except that a single door is permitted where the sources of ignition in the appliance are elevated in accordance with Section 304.3.
Exception: This section shall not apply to appliance installations complying with Section 304.6.

The way I'm reading this, since the pumps are not located in the garage but in a room adjacent to the garage, they do not need to be elevated. This is a public garage not private, so the last sentence of 304.3 does not apply. 304.3.1 requiring the two doorway separation only applies to fuel fired appliances but not to equipment, which is what the pumps are. A single door is all that is required since the boilers themselves meet the elevation requirement.

I don't necessarily like it, but that's what I'm seeing. Thoughts?
 
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images

Are you referring to something like this? Aren't those strain reliefs water tight? I guess if that joint weren't perfectly tight there could be a spark, but man I think that's a stretch....
 
Hahaha btw, is that picture I just nabbed off of the internet showing a few a code violations?
 
More along the lines of this:
1675116053474.png
Picture off the internet also, not from the actual jobsite. 12 pumps similar to or larger than this. Open windings.

The boiler isn't in question because all sources of ignition ARE elevated.
 
Oof, yeah, that's a tough one... Open windings could definitely throw a spark and if there were a high enough concentration of petroleum vapors there could certainly be ignition...
 
Tough call but what would your response be when the news reporter shows up after an event?

IGNITION SOURCE. A flame, spark or hot surface capable of igniting flammable vapors or fumes. Such sources include appliance burners, burner ignitors and electrical switching devices.

EQUIPMENT. Piping, ducts, vents, control devices and other components of systems other than appliances that are permanently installed and integrated to provide control of environmental conditions for buildings. This definition shall also include other systems specifically regulated in this code.

APPLIANCE. A device or apparatus that is manufactured and designed to utilize energy and for which this code provides specific requirements.
 
The problem is, 304.3 addresses appliances and equipment located in the garage. Not the case here. They are in a room that opens into the garage. 304.3.1 is where rooms opening into public garages are covered, and the only thing required to be elevated with a single door separation is fuel-fired appliances. Equipment and even electric only appliances like condensing units are not.

I initially failed it and the contractor questioned my call, citing the code sections. After re-reading it, I may not like it but I think he's right, the pumps less than 18" above the floor meet the code as written.
Maybe a need for a code change or at least a local ordinance?
 
klarenbeek said:
The problem is, 304.3 addresses appliances and equipment located in the garage. Not the case here. They are in a room that opens into the garage. 304.3.1 is where rooms opening into public garages are covered, and the only thing required to be elevated with a single door separation is fuel-fired appliances. Equipment and even electric only appliances like condensing units are not.

I initially failed it and the contractor questioned my call, citing the code sections. After re-reading it, I may not like it but I think he's right, the pumps less than 18" above the floor meet the code as written.
Maybe a need for a code change or at least a local ordinance?
Click to expand...
Wait and see if something blows up....Probably not....
 
The pumps are part of the equipment under the definition. Without them the boilers are useless. Maybe a gasketed sealed door might be a tradeoff. A positive pressurized room? Just think outside the code box that would reduce the chance of a vapor ignition and perhaps provide an equivalent level of protection without having to relocate the pump motors.
 
klarenbeek said:
Like I said, I don't like it but I'm also not in the business of making up code on the fly just because I don't like it....

304.3.1 is pretty specific in that it calls out fuel-fired appliances and nothing else.
Click to expand...
Yeah...Not calling you out or anything, it just might be less of a deal than we think it is...Betting the ventilation in the garage pretty much negates tis concern...
 
steveray said:
it just might be less of a deal than we think it is
Click to expand...
California code agrees with that statement:

305.1 Installation in Garages.
Appliances in residential garages and in adjacent spaces that open to the garage and are not part of the living space of a dwelling unit shall be installed so that all burners and burner-ignition devices are located not less than 18 inches above the floor unless listed as flammable vapor ignition resistant.

When the ICC copied the Uniform Mechanical Code they added stuff to make it look like they made it on their own.
 
# ~ # = &

klarenbeek, does the room with the pumps
have any source of natural ventilation air so
as to have enough "dilution effect" of any
stray fumes of fuel for the boiler(s) ?

& = # ~ #
 
There is exhaust being pulled out of the room with a gravity makeup air.
Mechanical room is about 1900 square feet, garage is about 15000 square feet, under a ten story building. Two 2.5 mBTU boilers, two chillers and 12 circulation pumps in the mechanical room, plus the potential for other equipment like condensers for coolers/freezers as the ground floor retail spaces get finished.
It just seems odd that the only thing addressed in rooms off a public parking garage are fuel fired appliances only. Apparently electrical sparks aren't as much of a concern as soon as its not located in the garage itself????
 
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