Underground garage smoke control

[BIPVguy]

Dear all,

Does anyone know what NFPA standard is related to mechanically ventilated underground garages? Any other reference is greatly appreciated.

I have 2 level underground garage where fresh air is introduced via car ramp on ground floor. The idea is to size my system (ducting, 2 speed axial fans) according to smoke exhaust criterion (10-12ach as opposed to that of ventilation 5-6ach).

Thanks

 

[DRWeig]

Hi BIPVGuy,

I'd be a hard sell on overdoing exhaust by a factor of 2.

You'll find your answers in the mechanical code, IMC Section 404 -- it covers totally enclosed garage situations.

Smoke removal for large areas is in NFPA 92B if you want to go that route. I'd check with the owner (and AHJ) first, though.

Good on ya,

Goober Dave

 

[BIPVguy]

Hi DrWeig,

Thanks muchly. Now, I realize that my approach is completely wrong resulting in oversized system. The trick is in smoke detector then. If CO>25ppm the system will start running and removing gasoline fumes (and smoke in case of fire eventually). I will design my system according to air flow rate around 1cfm/sqft parking space (ICM 2003,s404).

I found a good paper, published in January 2001, on the net

http://www.garasjeventilasjon.no/lager/Ventilation for enclosed parking garages.pdf

In summary, the paper suggests that ventilation rates for underground garages should be reduced (calculations based on Ashrae 62-1989!?). In ASHRAE 62-2007, ventilation rate of 3.6 L/ssqm for car parking is proposed.

Cheers.

 

[HiriseBuilding]

Most of our clients in high rise building are data call centers and most of them are having a back up A/C units for their server room. What are the necessary data to take when getting the cooling capacity requirements for server room?

 

[DRWeig]

Good on ya, BIPVGuy, I like the paper you found.

Let us know how your project goes!

Goober Dave

 

[BIPVguy]

Hi there Hirise Building,

Rule of thumb for internal cooling loads:
1) small IT centres (90-150 W/sqm)
2) large IT centres (500-1000 W/sqm)

The best approach is to get data from IT consultant as actual values depend on diversity.

Hope this helps.
Thanks