# Occupancy classification of Mechanical room



## Examiner

When you are calculating your square footage for possible occupancy separation, what occupancy group would you put a Mechanical room in?  Assuming the Mechanical room would not be the one with the refrigerant and BTU loads that would cause a rated separation.


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## Coug Dad

Mechanical rooms are not a defined occupancy.  If they are also used for storage, I would apply S1/S2.


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## TheCommish

unless they exceed the BTU input and ar classifed as a specal room, thay are accessory to the main use


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## Brookhaven 58

Table 1004.1.1 BC 2009 ed.   Mechanical equipment areas calc'd at 300 gross/occupant.


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## Big Mac

I typically assign an 'S1' classification and use 1:300


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## Examiner

Thank you all.


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## north star

*= =*

Examiner, 

Please refer to Section 508 & Table 508.2 in

the `06 IRC.....Sounds like an "incidental use"

room to me, depending upon the size and what's

being stored in there.

Big Mac stated:





> "I typically assign an 'S1' classification and use 1:300"


Why would you not assign a lower Occupancy Group like anS-2?.....If there is going to be a higher hazard type of

stored materials / stuff in the room, then yes, I would

also assign an S-1.......Just askin'...

Thanks!

*= =*


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## Big Mac

It could certainly be an incidental use depending on size whether it is also used for storage or not.  However, being an incidental use does not preclude the need to classifiy it.

Why would I call it an S-1.  Primarily because one cannot determine before hand what type of misc. items will be stored in this type of space.  This is of course assuming that it is not dedicated storage for primarily non-combustible materials.  In my experience that is pretty rare.  One of the certainties in life is that if there is an area that can be used for storage it will be used for storage.  My philosophy is to assume worst case scenario unless there is compelling evidence to the contrary.


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## Paul Sweet

If you are worried what people might store stuff in them, they would have to be classified H.  Half the ones I've been in have empty cardboard boxes stored next to a gas-fired water heater, and lots of extra janitorial supplies, etc.  See the Separation in Table 508 thread.

Realistically, they don't need to be assigned a separate use group unless it's a huge central plant.  Sprinklers and/or rated walls & ceilings take care of the fire hazard.


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## Big Mac

Structures or portions of structures SHALL BE CLASSIFIED with respect to occupancy in one or more of the groups listed below.  Section 302.1.


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