Flex Duct In Attic

Blown in insulation is cheap.

Flex duct in attic.

Ducts are to be part of what is inside the house not part of. Not part of what is in the attic. The straps that hold up the flex duct need to be no less than 1 5 wide. Insulated flexible duct r6 silver jacket is used in standard heating and air conditioning hvac systems and some venting applications.

Around that is the outside cover of the duct itself. Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water. The lower the cooler it is. The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports.

Type of ductwork system the least expensive duct system is a radial system of flexible ducts in an attic running to ceiling grates. This additional insulation provides greater thermal efficiency to save energy. They just tear through them smash them climb on. A layer of insulation covers this thin layer of plastic and blocks the heat from getting in or out of the duct.

The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum. Most attic ducts are insulated flex ducts that is flex ducts with r 6 or r 8 fiberglass insulation along with an exterior polyethylene jacket. The attic is a hot dirty nasty place. The duct has r6 insulation which contains 33 more insulation than the standard r4 2 product.

It s done this way because it s easier and cheaper to run a flex duct through a wide open space than to fit it through and around floor and wall framing. Ducts up high get tore up. Just blow the attic to r 38 and over the top of ducts if needed. The costliest are sheet metal ducts running in enclosed walls and ceilings.

The attic ductwork is flex duct work. Secure the webbing to the joist by hammering a 2 inch roofing nail through the webbing and into the side of the joist. It was new when the ac was put in 7 years ago. People can not carry ladders up into a attic and them place them onto 1 1 2 wide boards so they can climb over ducts.

Those are valid reasons to do it so the real answer is to make the attic at least semi conditioned space. Flex ducts consist of a spring that is wrapped with a very fragile layer of plastic. If ducts are to be installed in a vented uninsulated attic or crawl space hang the ducts with supporting straps or saddles of sufficient width and frequency to adequately support the ducts so that the ducts do not sag and are not pinched or compressed in a manner that would cause damage to the ducts the duct insulation or the duct air barrier covering. When these ducts are exposed to exterior air the plastic jacket never gets cold enough to permit condensation because the hot attic air keeps the plastic jacket warm.

Hold the loose end of a roll of duct support webbing against the side of a roof joist sitting directly above the flex. The higher in the attic the hotter it is. How to hang flex duct in an attic 1.