The house is single story and has a 3 5 ft crawlspace underneath.
Best flex duct for attic.
The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports.
Raise the webbing until the bottom of the flex duct sits 1 2 to 1 inch off the bottom of the attic floor.
Using this kind of ducting is best in tricky spaces where rigid ducts are not just possible to install.
Seal the ducts with mastic.
All ducts should be sealed using ul 181 rated duct mastic 1 and flexible ducts should be held in place with.
This type of ducting is best in tricky spaces where rigid ducts are just not possible to install or used to attach non flexible ductwork to an air supply outlet.
Flexible ductwork uses cheaper materials and therefore is a cheaper option.
The rigid insulation was saturated from condensation.
This means that fully extending the flex is a big deal and may be one of the most overlooked aspects of flex system installations.
Set your store to see local availability.
The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum.
The flex ducts were literally filled shut with ice in the low spots compressing the scant insulation layer beneath them.
Insulated flexible duct with metalized jacket r8 model fd 12r8 09 56 21 56 21.
This coating will help to keep the glass fibers from your airstream and excess noise from your home.
Pull the webbing back toward the joist to form a loop.
Use only what you need.
The straps that hold up the flex duct need to be no less than 1 5.
The prior owner just had a new ac system installed in which they switched from the equipment and metal ducts in the crawlspace to flex ductwork equipment in the attic where temps have regularly been in the 130 150 degrees this summer.
Kinks bends and turns need to be minimized in installation as these issues reduce air flow and could hamper the efficiency and effectiveness of the air conditioner.
I found instead a vintage 3 ton ac unit with 1 rigid insulation taped all over it and insulated flex duct snaking all over the poorly insulated attic.
4 rules for flexible ducts that remodelers need to know.
They are also used to install ductwork which is not flexible to a certain air supply outlet.
The fiberglass duct board is by far the most effective.
Slide the webbing under the flex duct.
You can find formaldehyde free insulation that also has an acrylic coating.
The more compressed the duct is when it s installed the greater the air resistance of the duct will be.
Another biggie that i see all the time is sagging ducts.
