Dryer Vent Direction

[Gibbcutter]

Is there any building code regarding which direction the crimped end should be facing?  I have a long run and the installer said it does not matter.

[srv52761]

Shouldn’t matter for the water vapor, it may for the free flow of the suspended lint particles.

[Cooler]

I would assemble it so the flow of the air goes over the crimp which enters the next pipe.  The point being if it goes in one direction there is a cut edge to trap lint, and in the other direction there is nothing to trap the lint. 

Also no screws or pop rivets for assembly.  Those will also catch and hold onto lint.  You want to use aluminum foil tape designed for that purpose.  It is amazingly strong and seals well.  It also does not protrude into the tube. 

Think like roofing materials.  You want the water to flow in the direction where it cannot get under the shingles.  The same concept will work for the dryer vent. 

I've been told that the flexible vent hose is not recommended as the lint will accumulate on the corrugated surface.

I re-did mine a couple of years ago using the tape only and rigid pipe.  A 20-minute job.  Easy.

[K. L. McReynolds]

No code I know about----but, uncommon sense says the crimped ends should not be facing air flow---moisture/lint trapping will happen.

[TDKPE]

No code I know about----but, uncommon sense says the crimped ends should not be facing air flow---moisture/lint trapping will happen.

Same general rule about plumbing, including water mains in the street and concrete pipes.  Convention, I suppose, but the flow is probably a tad smoother.  And in the case of dryer vent pipe, no sharp edges to catch lint, which only builds up once it gets started.

[MstrCarpenter]

I recently swapped out a "slow" dryer for a friend. Both simple electric dryers that didn't fit through the bath doorway. Remove a split jamb and 1 stud, old out, new in, re-install door unit. The last part of the project was installing solid vent pipe and a vent hood without the bird guard. There was only 2' of plastic corrugated and 10" of solid attached to the hood; packed solid with lint!

[Patsfan]

Is there any building code regarding which direction the crimped end should be facing?  I have a long run and the installer said it does not matter.

Two additional things to consider:

Most dryers have specs for how long the run can be. Typically 35 feet or so for smooth metal duct. Before you jump for joy, understand that every 90 count five or so feet toward that total.

Also, that vent should be at least three feet away from any door, window, vent/intake gas meter, etc. If possible, try not to locate it on the wall facing prevailing winds.

[Cooler]

I'm not sure how well they work or even how they work, but there are dryer duct booster fans that assist in long duct runs.

https://tjernlund.com/dryer_booster.htm


https://tjernlund.com/Tjernlund_LB2_Drye...500302.pdf