Dryer exhaust booster fan allowed by code? 1

[John_187]

There is a dryer exhaust vent, 4", where the length to the wall may be a little bit longer than what the instruction manual says is allowed. The dryer is commercial, see link page 8 for lengths.

https://www.coinop.com/admin/prod_lit/Documents/SalesLit/CED9160GW_Installation Instruction_EN.pdf

The dryer vent fan used is this:

http://vents-us.com/images/cat/507_320_cat_file.pdf

Is this dryer vent fan allowed by code? A contractor mentioned it might not be. I've never heard of this.

Thanks for the help

 

[chicopee]

If the dryer is electrically heated, then this situation may not be an issue with local and state codes. On the other hand if it is a gas fired drier then there is probably an issue such as: First is the fan rating rated for hazardous locations another word is it explosion proof in the event there is flame failure of natural or propane gas being exhausted? About wiring and switch are they compatible for hazardous location? Is the fan interlocked with drier operation?

 

[Compositepro]

Gas-fired equipment is inherently NOT explosion proof as there is always an ignition source. The safeties are on the gas supply. Here the issue is that the fan may disrupt the proper air flow to the burner. This is usually addressed by having an air gap between the equipment exhaust and and a powered vent. But, this does not answer the question about code requirements.

 

[chicopee]

I would still require that the fan ass'y be rated for hazardous location in the event all safeties incorporated in the ignition source fail. I agree with you on the safeties of the ignition system but an the exhaust fan is something unusual for such set up. Obviously the exhaust air will be initially almost saturated with water vapor but that will diminished during the drying cycle and there could be a problem. A non sparking fan blade should also be use in that commercial system. My thoughts.

 

[berkshire]

One other factor to consider, is that the booster fan be a type than can be easily cleaned, like a paddle fan, because of lint build up . On dryers it does not matter how good the lint screens are, some will always get through.
Some years ago when replacing the exhaust ducting on a bank of 10 dryers in a laundromat( Common Duct) we found the ducting to be 50% full of lint. This in spite of the fact that the laundry companies maintenance personnel were supposed to clean the ducts on a regular basis. It had cleanout doors for that. It is a good job we discovered that, before, a fire started in it.
B.E.

You are judged not by what you know, but by what you can do.

 

[MintJulep]

In general, allowed. IMC 504.5

https://codes.iccsafe.org/public/document/yc7355qxk7/chapter-5-exhaust-systems

The specific one that you link to, not.

You may find this informative.

http://www.fantech.net/globalassets/leaflets/dedpv-white-paper-fantech.pdf

 

[berkshire]

On reading the fintech Brochure what jumps out is the statement " Clean At once every 6 months ".


B.E.

You are judged not by what you know, but by what you can do.

 

[chicopee]

I haven't read the IMC504.5 brought up MJ, however, such code present the minimum requirements.

 

[Compositepro]

Chicopee, nothing else in a laundry dryer is explosion-proof. It would be pointless.