Duct Board Vs Sheet Metal

Flexible ducts are good for air quality because you are not breathing in fiberglass insulation lined ductwork like the fiber air ducts and they are mold and rust resistant unlike galvanized sheet metal ductwork.

Duct board vs sheet metal.

Sharp edges inside will cause material erosion. And then beyond that it s the ductwork is made of cardboard. The porous surface seems like it would affect air flow i understand properly sized this shouldn t be a problem collect more dirt than metal delaminate and come apart over time and are very hard to clean once dirty. Generally airflow is better with metal ducting after a couple of years typically because of the dust and.

And then that goes up maybe i don t know a foot and a half 2 feet. The idea of the porous insulation on the interior just doesn t seem like a good idea. I just don t know what that is. I don t know what kind of cardboard and i m sure there s a name for it.

If i am going to have a supply plenum run for approx. Up from the furnace comes a metal ducting duct work that goes up. You need a pro for this. Replace redesign the duct board with sheet metal.

Proper aspect ratio for velocity and pressure drop is more important than sheet metal. While flex ducts work best for short runs in a trunk and branch system metal duct works best for entire air distribution systems. There is a third option phenolic duct that is made of plastic foam with a foil liner on the inside and exterior. If you re going this far perform a flowhood test to determine where how much improved airflow can be had.

Poor fastened and sealed connections. Duct board is ok if the system design is correct and the duct and fittings are properly made and installed. The inner liner ribs restrict airflow more than sheet metal ductwork but not significantly. It hasn t been on the market long enough to weigh in on its merits and shortcomings and will not be included in this comparison.

Odds are the efficiency airflow of your duct system can be greatly improved. High air velocity will destroy the fiberglass material. It is not rodent proof. 25 feet should it be ductboard or metal and is hard pipe runs preferable over flex.

I have never liked duct board or ducts lined with fiberglass. When homeowners receive quotes from hvac contractors they typically are given two duct replacement options sheet metal or fiberglass duct board. There actually are a few reasons most hvac techs prefer metal ducting.