Can I use foil duct for Kenmore 700 dryer?
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.