Dryer vent with 4" PVC pipe

rjniles · 09-07-2008, 05:12 PM

I replaced a dryer vent that ran thru my crawl space for a distance of about 15 feet. The old vent was the plastic slinky with the wire coil. It was a mess, sagged and was full of lint. I replaced it with 4" PVC drainage pipe. The dryer works much better now and dries the clothes in much less time. My buddy says I have created a fire hazzard with the PVC pipe. I do not see how as the old slinky was plastic. Dryer is electric for reference. Any opinions or code issues?

Wildie · 09-07-2008, 05:34 PM

Quote:

Originally Posted by rjniles

I replaced a dryer vent that ran thru my crawl space for a distance of about 15 feet. The old vent was the plastic slinky with the wire coil. It was a mess, sagged and was full of lint. I replaced it with 4" PVC drainage pipe. The dryer works much better now and dries the clothes in much less time. My buddy says I have created a fire hazzard with the PVC pipe. I do not see how as the old slinky was plastic. Dryer is electric for reference. Any opinions or code issues?

I just installed a new dryer and the manual says "Do not vent with flexible plastic material.Rigid or flexible metal duct is to be used. In Canada or the US, if metal foil, it must be of a specific type identified as to be suitable for use with clothes dryers. In the US it must comply to UL Standard 2158A"
I think that your friend is correct!

handy man88 · 09-07-2008, 08:25 PM

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Quote:

Originally Posted by rjniles

I replaced a dryer vent that ran thru my crawl space for a distance of about 15 feet. The old vent was the plastic slinky with the wire coil. It was a mess, sagged and was full of lint. I replaced it with 4" PVC drainage pipe. The dryer works much better now and dries the clothes in much less time. My buddy says I have created a fire hazzard with the PVC pipe. I do not see how as the old slinky was plastic. Dryer is electric for reference. Any opinions or code issues?

I don't think PVC is meant to handle the heat coming from a dryer. Also, there's no insulation around the pvc pipe to prevent the hot moist air inside the PVC pipe from condensing during the winter before it leaves the outlet. This condensation can drain back to the dryer and pool.

Wildie · 09-08-2008, 12:44 PM

Quote:

Originally Posted by handy man88

I don't think PVC is meant to handle the heat coming from a dryer. Also, there's no insulation around the pvc pipe to prevent the ho moist air inside the PVC pipe from condensing during the winter before it leaves the outlet.

Thats a good point, unless the pipe runs in a heated area!

handy man88 · 09-08-2008, 01:58 PM

Quote:

Originally Posted by Wildie

Thats a good point, unless the pipe runs in a heated area!

True, if the dryer is in a heated basement, then that may be ok especially if it's pitched down.

If it's going through an attic because the dryer is upstairs, then that may be an issue.

1610 CUB · 09-08-2008, 03:52 PM

I don't know for sure, but I heard that static electric could/can be a big problem with pvc pipe.

Wildie · 09-08-2008, 08:57 PM

Quote:

Originally Posted by 1610 CUB

I don't know for sure, but I heard that static electric could/can be a big problem with pvc pipe.

I have a saw dust vacuum system in my shop that uses clear plastic tubing.
When installing this, I was instructed by the directions to run a bare copper wire inside the tube, that was grounded.
A spark in a dusty area can cause an explosion, so perhaps this would apply to PVC used as a dryer vent also!

Big Bob · 09-10-2008, 08:41 PM

Back to OP's Question. Any fire issues?

If we believe that appliances are made perfect and they will never malfunction... then we can duct with any reasonable combustible product we want.. RIGHT...

please let me know if I have not made my point....

handyman78 · 09-16-2008, 05:12 PM

Replace it with 4" aluminum pipe for clothes dryers-

handyman78 · 09-16-2008, 05:16 PM

Quote:

Originally Posted by Wildie

I have a saw dust vacuum system in my shop that uses clear plastic tubing.
When installing this, I was instructed by the directions to run a bare copper wire inside the tube, that was grounded.
A spark in a dusty area can cause an explosion, so perhaps this would apply to PVC used as a dryer vent also!

True- but dryer output is more often damp and fuzzy than dry and dusty

Big Bob · 09-16-2008, 06:53 PM

Dryer fuzz will not stay damp for long..

Girl scouts collect this to make fire starters for their merit badges.

try to keep your new duct clean....and don't miss any payments on your HO insurance.

**Termite** · 09-17-2008, 12:26 AM

PVC isn't appropriate or safe for dryer vents. I'd remove it and run it in solid 4" round duct.

sendres · 09-17-2008, 02:38 PM

I'm pretty sure the PVC just doesn't meet code. And practically speaking it would probably be fine and nothing would happen and likely it just hasn't been certified for that use. But if it something did happen, the HO insurance would likely not be worth the paper it is written on. They seem to frown on covering damage from code violations.

Big Bob · 09-17-2008, 06:24 PM

Actually, most HO & DP policies do cover " silly things that homeowners do". not permitted, or not to code efforts, improper installation etc..

The loss must meet the quick and sudden standards.

Getting money to fix the house...is little comfort if there is loss of life or limb.

Ever put that last load of wash in the dryer before you went to bed?

OP... change the PVC to smooth metal duct.. if not for your sake ... then the safety of the ones that live with you.

sendres · 09-17-2008, 07:13 PM

You may be right. The case my neighbor was involved was probably on the more extreme end. He used PVC to hook up his garage heater. As a"temporary solution". Let just say he's rebuilding it now, he almost has it done again. Fortunatly no one was around and it was detached. For some reason the insurance company didn't cover it.