Duct Board Vs Sheet Metal

Up from the furnace comes a metal ducting duct work that goes up.

Duct board vs sheet metal. There is a third option phenolic duct that is made of plastic foam with a foil liner on the inside and exterior. High air velocity will destroy the fiberglass material. Duct board vs metal plenums supply is on perferable over the other. And then that goes up maybe i don t know a foot and a half 2 feet.

Duct board is ok if the system design is correct and the duct and fittings are properly made and installed. Odds are the efficiency airflow of your duct system can be greatly improved. Coat seal the interior of the duct board using an airless sprayer. I don t know what kind of cardboard and i m sure there s a name for it.

You need a pro for this. Proper aspect ratio for velocity and pressure drop is more important than sheet metal. Poor fastened and sealed connections. Metal ductwork needs design measurement and installation by or with the help of an hvac professional.

The inner liner ribs restrict airflow more than sheet metal ductwork but not significantly. 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. 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. I have never liked duct board or ducts lined with fiberglass.

And then beyond that it s the ductwork is made of cardboard. The idea of the porous insulation on the interior just doesn t seem like a good idea. While flex ducts work best for short runs in a trunk and branch system metal duct works best for entire air distribution systems. 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.

If you re going this far perform a flowhood test to determine where how much improved airflow can be had. There actually are a few reasons most hvac techs prefer metal ducting. Generally airflow is better with metal ducting after a couple of years typically because of the dust and. It is not rodent proof.

25 feet should it be ductboard or metal and is hard pipe runs preferable over flex. If i am going to have a supply plenum run for approx. Replace redesign the duct board with sheet metal.