Dryer Roof Vent. Big Boxes?

[Al Bundy]

Anybody ever see them? I gave a quick scan for one at HD but didn't see it. Any idea what they run for like plastic. I mean $15 or $50.

[Roy Starrin]

?sc=2&category=26

[CDET 14]

Don't use these. They will collect lint like crazy and they are hard as hell to clean out.

Alisa LeSueur Certified Dryer Exhaust Technician

Roy Starr> >

[Al Bundy]

"CDET 14" wrote in news: [e-mail]:

OK, I understand lint collection and blockage is a consideration. Long dry times, burning out elements, fried thermistors, etc. even to the extent of a fire hazard.

Minimizing lint blockage is exactly why I am considering this option. It's the shortest and straightest run. Here is the layout:

or - On the top is what I am considering. Comparing to the bottom where it would be gable vented, it removes about 17 ft of length from the attic.

Roof: 6' ( attic rise) Gable: 3' (attic rise) + 5' (90 deg turn) + 15' (run to gable) = 23

Interior venting: 8' + 5' (90 deg turn) + 2' (to dryer) = 15'

Total venting length:

Roof: 6 (attic) + 15 (interior) = 21' Gable: 23 + 15 = 38'

I don't think 38' is legal here and besides, it's not too smart. With the roof install, I believe any residual lint would drop to the cleanout at the 90 degree bend at the dryer. This cleanout is (probably) a piece of metal stove pipe with a cap on the bottom. Easily accessable from below furnace where the air intake grid and filter is.

This routing is about the only option I have. The only other exit is out the side of the laundry room where there are cabinets all the way to the side wall in the kitchen. Check this out. When I moved in this repo HUD wreck they had the 4" vent going through the side of the laundry room wall and laying exposed (no soffit) on top of the wall cabinets and out the kitchen wall. Not quite my decor taste.

You thoughts Alisa? Or anyone elses input of course.

Al, Professional Wanna-be...and not too shabby a one either:-)

[CDET 14]

I see your layout. Let's clarify some points:

1. The 'residual' lint that will drop to the clean out. The problem with lint is that it sticks to the sides of the vent pipe and slowly builds up to restrict air flow. Sure, some will drop with gravity once the dryer blower stops, but that is not the big issue.
2. The metal stove pipe can be used for any or all of the vent route, but please follow these guidelines: As the pipe sections are fitted, the male end should face away from the dryer. This is the opposite of stove pipe instructions. There should be no screws. Use aluminum tape (not duct) to secure seams. The diameter should be 4". Bigger is not better. The dryer blower is designed to push lint through a 4" pipe.
3. The prior owner's route sounds shorter. May I suggest the same vent route, but build a chase around it to look better. It could be a design accent. I assume that the termination was to the exterior of the structure...
4. Your picture shows a "hose to attic" and I hope this is a rigid metal pipe.
5. Yes, 38' is too long. If you choose to go this route, you must be diligent on keeping it cleaned out.
6. My original concern was the termination box. The boxes that lie flat on the roof look better, but collect lint better, too. They are also tough to clean out from either end. If it will terminate on the side of the structure, as your picture suggests, a standard side vent will work. Please put a critter guard on the end, not a mesh screen. Birds are the problem and the built in flap is not a deterent.