Dryer Vent

[fqp25]

Dryer vent for single family residential, I know vinyl is bad, but how about flexible foil type, which transitions into apparently aluminum rigid vent pipe, which exhaust out side?

Go, or No Go?

[Les]

"flexible foil" typically is mylar - a plastic and not allowed in our jurisdictions and not code compliant.

For what it is worth - I encourage inspectors to think "common sense". Vinyl is not allowed, so why? Mylar not allowed, so why? Of course you could read all the literature from Mfg and find none allow anything other than ridgid pipe.

[hausdok]

Hi,

I can't find it in the CPSC archives and my office copy is somewhere in one of these huge mounds of paper in here and I've not been able to find it. However, back in '97 -'98 CPSC made a stink about any type of corrugated pipe and said that it was unsafe, citing a study they'd done of over 17,000 fires that had occurred over a 4 year period in the US that could be traced to corrugated or occluded dryer ducts. That's a pretty strong argument to stay away from anything flexible and corrugated.

ONE TEAM - ONE FIGHT!!!

Mike

[fqp25]

I am pretty clear on the flex, how about the aluminum? Is this acceptable for dryer vent? Would you recommend B vent, when it goes through the exterior wall?

When I was in construction we always treated dryer vent like any other exhaust vent.(When we got stuck installing it) I can't remember anybody quoting the exact code for residential dryer vent. Some accused us of overkill. I guess we took a "better safe than sorry" posture.

Thanks for the help

Frank

[Mike Lamb]

Beware, the dryer duct. Fire and CO hazard.

Slinky foil and/or plastic is allowed by NO major manufacturer’s instructions for ducting. Manufacturer’s instructions supercedes any code.

The inevitable sagging, collapsing, kinking of this crappy product is the problem. Friction, damned friction.

Here’s an article I got printed in a local rag:

Don’t Get Burned by the Clothes Dryer!

By Mike Lamb

Clothes dryer lint is an ingredient used in fireplace starter logs. Savvy campers bring dryer lint on their trips to easily start campfires. Take a clump of your clothes dryer lint outside and put a match to it. I have. It doesn’t just catch fire, it bursts into flames.

That said, it’s not surprising that over 15,500 fires a year are started by the clothes dryer (this figure has decreased from over 22,000 fires in the 1970’s). So obviously, it’s important for everyone to take dryer exhaust seriously. With gas dryers, carbon monoxide poisoning also becomes an issue. Here’s what to look for:

Check behind the dryer at the flexible transition duct. It’s usually flexible right behind the unit so the dryer can be moved away from the wall for cleaning and installation. Any flexible white plastic or silver foil type duct is the absolute worst and should be replaced with solid or semi-rigid flexible metal.

Check any duct behind the dryer for crimping or severe bends. ALL duct after this so-called “transition ductâ€

[gtblum]

Transition ducts shall not be concealed within construction.

Are flexible transition connectors considered to be concealed within construction when they pass through a wall and or a floor?

Can they be used for this?

[exploreparadise2]

The question that began this thread asks about flexible duct that transitions to the dryer duct. As pointed out earlier, transition ducts shall not be concealed in construction (M1502.4), so, no they can't pass through a wall or floor.

The same code section also specifies that a flexible transition duct shall be listed and labeled in accordance with UL 2158A.

Here is a manufacturer of transition duct that conforms.

Quietflex

[Mike Lamb]

The same code section also specifies that a flexible transition duct shall be listed and labeled in accordance with UL 2158A.

Here is a manufacturer of transition duct that conforms.

Quietflex

I call out foil ducts as bad since I am aware that nearly all of the manufacturer's instructions I have read don't allow them.

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[Kyle Kubs]

So I guess this wouldn't qualify?

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Or this?

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What's frightening is I didn't even have to look for these, they were just my last two inspections. And yes, that is a gas dryer with the bathroom exhaust fan vented into it.