We don't deal with very many Major Repair Garages (none since the adoption of the 2008 NEC) but I have one that I'm reviewing right now, so I wanted to get some input from all of you on Section 511.3(C)(1)(a). My particular question is: in order to satisfy this section and avoid classification of the floor area, does the ventilation system need to be running whenever the shop is in use? Or, if the system is in place and can be turned on by the occupants as needed, is the requirement satisfied? It would be easy for example, to tie it in so that whenever the lights are on in the shop, the ventilation system runs, but would requiring that be requiring more than the code requires? The words "where there is a mechanical ventilation system providing a minimum of..." implies to me that the system needs to be running whenever the shop is in use.
511.3(C)(1)(a) Major Repair Garage
- Thread starter eprice
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- Mission Viejo, CA
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- Professional Electrical Engineer
When ventilation is used as the basis for reducing a location's electrical area classification, it is presumed to be continuous; otherwise, how would you know it has been on long enough? “A minimum of four air changes per hour or one cubic foot per minute of exchanged air for each square foot of floor area” is not too onerous.
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