Clothes Dryer Exhaust Vent

[antonio09]

I have a high rise building +/- 17 story, i want to use a shat with an exhaut vent duct. I will have 34 gas clothes dryer, I need to know the demand of these appliance in order to design the ductwork. By the way the duct will have the same dimension in the total lenght with a backdraft damper in the bottom with backdraft damper in each dryer.

Regards,


Antonio

 

[imok2]

Does the mfg have a web site you can access, if not you will have to call and get info or find a distributer.

 

[sloyal]

I've seen this done before, it's a costly project.
First the shaft must be lined. NO SHEETROCK! I've seen sheetmetal duct & Mylar (wallpapered) used for the linings.
Our local code official required sprinklers as well.

Next the dryer connections must not face each other so that one blows into another. I'd shy away from back draft dampers in the ducts as they will collect lint.

The shaft also must have an access hatch at the bottom for cleaning out the lint (believe me it will gather fast)& a drain. Ours was a fire rated access door, as the shaft was fully rated (due to the floor penetrations etc...) There were no rated dampers at the dryer connections.

At the roof penetration a 2 (or 3) speed exh. fan was curb mounted. This PRV operated constantly at a lower speed to exhaust a cfm equal 1/2 of the total dryer exh rates. When more than (in your case) 17 of the 34 dryers were in operation the blower would run a full speed to cover the total of all dryers in operation.
The thought was, with no dryers in operation we would essentually provide constant exh to all the laundry room.
Of course there was no way to balance for equal exh amounts, so I'm sure some nearest the top were "fresher" than those lower.

I know the code officials were all initially all over the idea, but they liked & approved it & it's been in operation for over 15 years.

I was only in on the initial "conceptual" design & didn't do the final calcs for cfm, etc...
Nor do I know what the final interlock controls for the blower were.
I know we spoke of electrical &/or gas "I'm drying now" controls, talk of pressure sensors, & others.
Any sensors in the shaft WILL collect lint & I don't think they were used. (I'm sure the sprinkler head has an afro by now)
I know some were talking of bath fans using the same shaft, but I don't believe this was done. (cool damp air & lint)
Also, I believe an upblast fan was selected as concerns for lint buildup on the roof were raised.
Ours was "Mylar" lined & issues of fire ratings etc... were brought up & addressed by those in on the final design. I don't know if Mylar was the actual product installed, nor the type of "wallpaper" paste.

Hope this gives you something to noodle over...
good luck
slj

"The rain it raineth every day
Upon the just and unjust fella
But more upon the just because
The unjust hath the just's umbrella."