Thread: New fangled dryer vent exit!

Was asked by my son in law's to clean the dryer vent system a while back. Hadn't been cleaned since the house was built 10 years ago. This was the existing "system" for the last fifteen feet of the run. Outside cover is attached to this flex heating pipe! Love the "notch" in the floor joist!!

Daryl, that joist appears to be sitting on a foundation wall, rim type joist. That notch should not be an issue, IMO.

Originally Posted by Mark Ryan

Daryl, that joist appears to be sitting on a foundation wall, rim type joist. That notch should not be an issue, IMO.

It hangs just inside the wall edge not touching the wall. I removed this line and rerouted the duct to another location next to the other "notched" opening mentioned in another thread using galv. line the entire run. Heat duct flex line is plastic and a fire hazard. Never should be used in dryer vent system. Just wanted to show what I came across. This one will be fixed by sistering another section of floor joist next to this one at least four feet in each direction glued and screwed.

Originally Posted by Daryl Roche

It hangs just inside the wall edge not touching the wall. I removed this line and rerouted the duct to another location next to the other "notched" opening mentioned in another thread using galv. line the entire run. Heat duct flex line is plastic and a fire hazard. Never should be used in dryer vent system. Just wanted to show what I came across. This one will be fixed by sistering another section of floor joist next to this one at least four feet in each direction glued and screwed.

Dryer exhaust venting should be smooth walled metal with no penetrating fasteners only high temp foil tape a connections with the pipe connections telescoping towards the exhaust direction Floor joist is an easy fix by scabbing a 2 x under notch and fastening to mud sill with pt wood

Originally Posted by frazier jeffery

Dryer exhaust venting should be smooth walled metal with no penetrating fasteners only high temp foil tape a connections with the pipe connections telescoping towards the exhaust direction Floor joist is an easy fix by scabbing a 2 x under notch and fastening to mud sill with pt wood

Also, the maximum dryer vent length should be only 14' total with only 2-90 degree bends per the Uniform Mechanical Code.

Originally Posted by Thom Huggett

Also, the maximum dryer vent length should be only 14' total with only 2-90 degree bends per the Uniform Mechanical Code.

Thom, most manufacturer installation instructions specify much longer than that. I see the duct exceeding the 14 foot in most townhouses/condos. For instance, a GE gas dryer maximum recommended length is 45 feet with two 90 degree elbows, and is also dependent on the exhaust hood type. Doesn't the code specify the maximum, or refer to the installation instructions?

Originally Posted by neal lewis

Thom, most manufacturer installation instructions specify much longer than that. I see the duct exceeding the 14 foot in most townhouses/condos. For instance, a GE gas dryer maximum recommended length is 45 feet with two 90 degree elbows, and is also dependent on the exhaust hood type. Doesn't the code specify the maximum, or refer to the installation instructions?

Neal, you are correct in that the code does prefix the 14' requirement with the following: "Unless otherwise permitted or required by the dryer manufacturer's instructions and approved by the Authority Having Jurisdiction...".