Gas dryer vent pipe...

[blazenut]

Is it absolutely necessary to use solid metal (not flexible metal) vent pipe when using a gas dryer? I've done a bit of research on my own, most say that it is necessary due to the condensation issues with gas appliances. Your thoughts?

[Bill Kibbel]

A dryer exhaust duct should have a smooth interior surface. Flexible "transition ducts" (<8') are permitted for connecting the dryer to the exhaust duct.

[Neal Lewis]

It's not that the dryer is a gas appliance. There's a huge amount of water in the clothes to combine with the lint and coat the interior of the exhaust duct.

[hausdok]

Hi,

The Consumer Product Safety Commission published an alert way back around 1997-98 wherein they basically condemned the use of any flexible connectors and ducting for dryers. They used to have a really nice graphic on their site that illustrated the problem but I can't find it any longer.

Basically, their position is that the moisture-laden air from the dryer gets slowed down by corrugated connectors and ducts, condenses in the duct and wets the inside surfaces and this traps lint that gradually builds up until it closes off the duct. If it's a gas dryer and the safety sensor fails, this will force CO back into the home and, regardless of type, if the safeguards fail the lint can ignite. CPSC did a study of fires in American homes from 1994 through 1997 and discovered that more than 17,000 fires had been caused by corrugated ducts and/or connectors.

CPSC's position was that only a smooth-walled metal connector and duct should be used; that the joints should not be screwed together and should be sealed with self-adhering aluminum foil tape and should be swabbed out annually from the dryer to terminus.

I sure wish I could find that friggin graphic from 1997!

ONE TEAM - ONE FIGHT!!!

Mike