laundry room in apartment building

[317069]

Hello All

I have 7 gas dryers in laundry room in small apartment building.
- is ther any special recomendations to connect thier lent vent to a common exhaust duct
- is ther any special recomoendation for this laundry room.

Thank you all

 

[berkshire]

Yes,
Put plenty of cleanout access holes in the duct in any horizontal section.
Even if the lint filters are good on the dryers, some tramp lint will escape and get into the duct,where it will settle and partially block the duct over time. This can also be a fire hazard.
B.E.

 

[DrRTU]

The IMC and NFPA limit you to 25 feet of ducting unless you can prove the dryer has “extended” capacity. A few dryers do have extended capacity but most dryers are owner provided. The codes vary upon year.

I would install a cleanout at the bottom of the shaft. I keep the 4” run out as short as possible by having the shaft next to the laundry area. I size the shaft / fan for the following: dryers at 150 CFM each, size the shaft at 1200 to 1500 fpm, 50 % of the dryers in use. I like to use Greenheck kitchen exhaust fans series C type fan at top of the shaft. This is an up-blast fan with motor out of the steam and is good with dirt loading on wheel. No backdraft damper. Fans run 24-7. I have not seen a stall or unstable flow issue with zero dyer operation. Pay close attention to NFPA 54 and IMC section on venting, you do not want to get roped into a distance to combustible issue.

Exhausto has an excellent fan system for this application.

http://www.enervex.com/contents.aspx?page=MDVS

 

[cdxx139]

Makeup air has given me issues on my last laundry project. Design for it early, I recommend a dedicated unit. Its too much air to pull from the house system

knowledge is power

 

[317069]

Thank you for your help
the duct will be horizontal duct, I am thinking to go with individual duct for each dryer.
if I coonect them to common duct, do I have to provide special fiitings in cas some of them were ON, and the other were Off.
Regards

 

[cdxx139]

If you tie them all to a common duct you will need an engineered system. An exhaust fan sized for all dryers on, and with a VFD that measures and maintains a specific static pressure in the duct.

knowledge is power

 

[Wareagl487]

Exhausto makes an engineered system. Works well.

http://www.enervex.com/contents.aspx?page=MDVS

 

[317069]

Thank you for reply.
do I have to provide the duct with an interna protection against fire hazard?

 

[cdxx139]

Fire dampers are against code here. May have to firewrap if you need to penetrate a fire partition.

knowledge is power