Electrical room ventilation

[Ellement]

An electrical room with a 200amp/240v panel in the basement of a restaurant that?s also home to 4 refrigerant cooling compressors, bad idea to put them there as in the summer this room gets very hot with all the compressors running. Until it recently burnt out there had been a small vent fan exhausting to the outdoor area under a deck, not much help but better than nothing I suppose. Unfortunately the building is very old and the walls are 2 ft. thick with stone which doesn?t allow any other exterior venting other than the 12? X 12? hole that?s there now.

I?m looking to replace the existing fan with a high CFM evacuation fan to exhaust out the same 12?x12? hole, I?ll have to have the fan itself a few feet inside the room and channel it out the hole through a 10 or 12? pipe. This assembly will be about 2.5 meters from the electrical panel. Finally here?s my question, is there any code restricting exhaust vents in an electrical room, or under what conditions? My concern is that in case of fire the flames could be blown through the vent and under the wood deck outside.
Thanks

[twh]

Try the National Building Code. There may be a requirement to install a fire damper or smoke detector, or to interlock with the fire alarm system.

With a high CFM fan, keep in mind that the exhausted air needs to be replaced. Preferably, not down a chimney.

[Ellement]

Once again all good ideas.

Not much room for a fire damper,I was actually thinking of a smoke sensor linked to a cut-off relay to interrupt the AC from the fan, this would serve a dual purpose. I could make it myself, but then it wouldn?t be CSA approved and therefore a possible liability issue.

So if anyone out there would know of such a thing, here?s your chance.

How about other sites that deal with different aspects of construction, ventilation, HVAC or general construction, are they out there?

[neil seidner]

I'm not sure what the code requirement is, but I believe a fire damper in the duct would work to prevent the wood deck from catching on fire.

[u2slow]

Last time I was looking at smoke detectors at Home Depot, they also had a relay module to hook up to your furnace. Idea being you don't want the furnace spreading the smoke around in case of fire. Maybe that'll work for you?

[Tony Moscioni]

3.6.2.8. Electrical Equipment Vaults

(9) Every electrical equipment vault shall be provided connected to a covered sump capable of holding all of the with a ventilation system designed in conformance with Part 6 liquid from the largest item of electrical equipment, and the
to prevent the ambient temperature in the vault from connection shall have a noncombustible trap to prevent the exceeding 40 C (104 F). spread of fire from the vault to the sump.

(10) Where the vault ventilation system in Sentence (9) is directly from an outdoor area by natural ventilation without the use of ducts, and where the electrical equipment is the principal source of heat, the combined net area of inlet and
outlet openings shall be not less than 0.002 m /kVa (3 2in /kVa) of electrical equipment capacity with a minimum of 20.093 m (144 in ), except that 2 2

a) where equipment in the power class as described inCAN3-C88, Power Transformers and Reactors is installed, ventilation requirements are permitted to be based on the actual full-load losses, or

(b) where the equipment is installed for emergency
purposes only and is not normally energized, it need not be considered in determining the ventilation requirements.

(11) In the vault ventilation system in Sentence(10), the inlet for fresh air shall lead from an outdoor area and shall 3.6.3.1. Fire Separations for Vertical terminate at a point not more than 1 000 mm (3.ft 3 in) above the floor level of the vault.

(12) Where the vault ventilation system in Sentence (9) is a mechanical system, it shall be separate from the system for the remainder of the building and shall be designed so that

(a) the vault temperature is thermostatically controlled,

(b) the fan is located so that it may be serviced without
danger to personnel,

(c) a high temperature alarm is provided in the vault,

(d) the system is automatically shut off in the event of a
fire in the vault, and

(e) a filter is provided in the air inlet if there is a possibility of dirt being drawn in.

(13) All ventilation openings shall be protected in conformance with Sentences 6.2.3.17.(4) and (5) and the protection shall be installed in such a manner that it cannot be removed from the outside by the use of common tools and it is
tamperproof.

(14) Except as permitted in Sentence (15), the floor of the electrical equipment vault described in Sentences (1) and (2) shall be liquid tight and surrounded by liquid tight walls and
sills of sufficient height to confine within the vault all of the in Sentences (1) and (2) may be provided with a floor drain liquid from the largest item of electrical equipment, but to a
height of not less than 100 mm (4 in).

Tony Moscioni
Electrical Inspector
Electrical Safety Authority