Dryer vents in commercial buildings

[fireguy]

We have been asked to clean/modify some dryer vents in grocery stores. An FM in our service area asked a grocery store to have the dryer vents cleaned. There have been some dryer vent fires in that jurisdiction.

We cleaned one vent that had to be brushed 3 times. We used a length of chain to weight our rope from the roof to the dryer room, the lint was that thick. The second took less than 15 minutes. Some of the vents have 90° bends and rise 20 feet in the air. What we propose to do is to use a dryer vent filter, mounted on 4 inch metal duct. Then the filter woluld be serivced on a regular basis. The vent would not vent outside, but inside the building. My concern is the amount of moisture we would introduce to the interior of the building. These stores are the size of a Home Depot or Lowes, similar foot print, similar height. One dryer is in a room approximatle 12 x 12, ceiling height 8 feet, with a wall opening the same size as a commercial door. The second dryer is in a room 40 by 40 with a ceiling height of 15 feet.

 

[fatboy]

Not exactly sure what you are asking, you want to disconnect the original vents to the exteriors of the buildings, and terminate inside through a filtering system? Of course there will be a moisture issue, but whether or not it is problematic would depend on your climate at these locations. Looking at it from an inspectors standpoint, I wouldn't buy it, you are taking a code compliant installation, and turning it into non-code compliant. My personal opinion is the FM that asked for the cleaning was a bit over the top, sure there are maintenance issues for buildings, but I think requiring dryer vent cleaning is beyond his scope. If anything, see a mechanical engineer and design a pre-filter system that can be serviced inside the dryer rooms, but that still vents to the exterior. JMHO

 

[cda]

I ask for it constantly

Sure there is a code section that can back it up¡¡¡

But they do have to be vented to outside Do no think there is an exception

 

[fireguy]

I did find in my 2007 Oregon Mechanical Specialty dryer vents code requirements, Section 504. But we also have stores in other states My next step is to check the requirements in the other states.

 

[cda]

To include requirements for cleanouts

Which kinda implies the code wants them cleaned out

 

[peach]

some jurisdictions allow booster fans in the duct.. but it still needs to go outside; see this alot in high rise multifamily; one or two cleanouts necessary in additon to the fan (which I'm not sure is actually allowed by code.. local thing).