I pulled my dryer, and am reinstalling it. It had a semi-rigid metal transition duct, which was all bent out of shape, and looked like it had some holes forming (see pic). I did homework, and read a site talking about how the aluminum foil transition ducts are the only ones UL listed, and at least at Home Depot that was true, the semi-rigid were not UL listed (except for the expensive GE dryerflex one). So I installed the foil duct, and after taping the ends and getting everything set, I turn around and see a warning sign on my Kenmore dryer saying don’t use Metal Foil ducts to vent. Does this include the transition vent? If not, why couldn’t I use the foil vent? Is it something specific about this dryer? In general, the info out there on transition vents are all over the place in terms of rules and suggestions, looking for some concrete expertise. I probably wouldn’t thought much of it, but a neighbor just recently had a dryer fire in their home, so it’s on my mind, and I want to get this right. In our condo association, we are required every 2 years to have a professional dryer vent cleaning. 
Use foil duct for Kenmore 700 dryer
dryervent
Related Solutions
Duct Tape is good for a lot of things, except duct work! It will eventually dry up and pull away from the heat in the vent.
I would bend/dent one of the ends slightly so that it will fit easily inside of the other. Then I'd secure it with proper HVAC foil tape, followed by a clamp around it.
Foil Tape
(source: homedepot.ca)
Metal Gear Clamp
(source: homedepot.ca)
I went through this recently with my girlfriends dryer. Here is what I learned:
- Her outside vent hood seeped rainwater, not much but enough
- Her ductwork had a tiny amount of lint which soaked up the rainwater
- Her “outside air” ducting for the all-electric central heat and air system damper didn’t open all the way causing the air to be drawn from and through the dryer ducting. The moisture in the ductwork lint was drawn into the clothing left in the dryer. (Her house is new and sealed very tightly!)
An additional clue something wasn’t right was indicated by the exterior vent for her kitchen cook stove - it “rattled” when the air conditioner ran!
Solution:
- Replaced the dryer ductwork and exterior vent.
- Disassembled dryer and cleaned entire dryer ductwork path
- Cleaned the central air exterior air feeder pipe, cleaned the exterior dampener
- Replaced furnace filter.
- Cleaned a/c condensate pipe (ran hose water through it until it was no longer draining “green” water)
- Fixed her supper on the Weber charcoal grill.
She is happy now. The dryer no longer “stinks” from the “wet lint” smell, her clothes remain dry and her air conditioner is working better.
Related Topic
- Boosting a dryer vent with an inline booster attached to the main line with a wye
- Terminate the dryer vent next to the gas meter
- Adding exhaust fan to semi-rigid dryer duct
- Is it safe to use a flexible duct near the end of an 18ft dryer exhaust run
- Dryer vent: proximity to electrical wires
- Is it safe to use foil heat tape inside the dryer
- What type of duct should I use for a clothes dryer exhaust
Best Answer
Gas driers must use metal vent. I prefer actual metal pipe. Aluminum flex reduces air flow significantly and even if not dangerous will lengthen the time it takes for cloths to dry. Gas driers have carbon monoxide flowing through the vent. Would you want your water heater or furnace vent using foil venting material? Granted a clothes drier vent doesn’t get as hot but if it rips that would not be good.