I've used plastic dryer duct for 46 years and never had a problem. Now all of a sudden you hear about dryer fires all the time. Why in the world would you want to use metal when it builds heat? My ducting lays on the floor and goes right out the adjacent wall and there is no kinking or drooping. I check it for lint periodically and never have had to remove any appreciable amount. If after 46 years of marriage 3 children, 7 grandchildren and 1000's of loads of laundry, there has never been any problem. In years past you never heard of anyone you knew or anything on the news about dryer fires. Why did they decide to change? The plastic could melt if your dryer malfunctioned, but it doesn't build up heat and the lint slides through with no problem. You could alway support it with hangers if you had to thread it through walls or other obstacles. It sounds to me like some company told everybody to stop using plastic so they could sell a more expensive metal product. Profit greed is usually the catalyst for change.

Our home is 2180 s.f. Split heat pump is a 3.5 ton unit. There are 11 floor registers inside. The air return in the hall way ceiling is 20x25 inches. Have been getting quotes for a new heat pump and two contractors have said the return is inadequate. One said to enlarge the existing one to 30x35 or something like that and the other said put a new return at the other end of the house. Any comments, please.