Flex Duct Vs Sheet Metal Duct

I have seen many leaky metal ducts in crawl spaces as well.

Flex duct vs sheet metal duct.

Fiberglass lining is used to insulate air ducts from heat loss or to avoid condensation in cases where the supply air is very cold or there is a high ambient humidity in the plenum. 1 10 5 25 per foot insulated flexible duct 4 to 16 diameters used as branches or in radial duct attic systems 2 30 13 00 per foot round and oval sheet metal duct 3 to 8 diameters typically used for trunks in small homes and. Some sheet metal air ducts are lined with an external or internal fiberglass duct liner. Flex ducts are better for existing trunk and branch heating and cooling systems.

Metal ducts are more rigid due to the nature of steel making them ideal to build an entire hvac system. I ve only been building since 1995 so i can t say for certain why we left the sheet metal guys behind but i suspect it was manly for cost reasons. Here are the itemized costs for the most common types of ductwork and supplies needed to complete installation. Their shape and size also allows them to be installed in locations that would not accept full sized sheet metal ductwork.

Sheet metal ducts are less likely to incur dangerous mold and growths because their surfaces are non porous and smooth. Also i think spider webs are more likely to form in metal versus flex. While sheet metal ductwork tends to be a better long. In comparison to metal duct flex duct is easier and faster to install.

While they tend not to last as long as sheet metal they are very cost effective. Flexible ducts are made out of corrugated plastic often wrapped in insulation. I don t know why but i have taken metal pipe apart to find a lot of crud which i don t think would live in flex duct. In this video i ll make a case for going back to rigid metal ducts for your trunk lines and keeping your flexable ducts to the last 10 or less of a.

Flexible ducts are fairly easy to install and will often cost less than the rigid ductwork.