Ventilation/construction requirements

[edmenold]

Thank you in advance!!

Have a client (in house eng)who is installing an enhanced walk in oven. Disagreement over construction standards.


stats:

480v/3ph/6o hz---115 amps-oven
recirculating 7,000 CFM @ 7 1/2 HP fan motor
exhaust-600 CFM @ 1/2 HP fan motor

TEMP- 500 deg F maximum
150 to 350 deg F normal operating temp
75 deg F above ambient minimum.

I suggest single wall spiral (incorporate a high temp flex connection)with a double wall posi vent thru roof with stack terminating +/- 6'-0" above roof line. Exhaust duct would be under positive pressure. This would meet NFPA 70 & 86. verus a welded schedule 40 pipe run (his Idea).

Please comment.

 

[ChasBean1]

Does the oven manufacturer suggest anything or are you building this from scratch?

 

[edmenold]

No, suggestions fron oven manufacturer except NFPA 70 & 86

 

[ChasBean1]

NFPA 86 refers to 91 refers to SMACNA and none say exactly what needs to be done for oven exhaust (far as I could see). I think I'd side with you. You want a double wall, not just a sched. 40 iron pipe...

 

[DrRTU]

I would use a commercial positive pressure material such

http://www.selkirkcorp.com/commercial-and-industrial/product.aspx?id=226

Depending on local code and your design spec, you could get by with single wall material up to the positive pressure material at the roof. Local codes may require a heavy gauge single wall and extended distance to combustibles.