How do you insulate air duct insulation?

Asked By: Frode Veevers | Last Updated: 29th February, 2020
Category: home and garden indoor environmental quality
4.8/5 (403 Views . 18 Votes)
When insulating HVAC ductwork, use a foil faced fiberglass insulation with an R-6 or higher R-value. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Make sure the foil surface of the insulation is free of dust before applying the tape.

Click to see full answer


Regarding this, does ductwork need to be insulated?

Insulation is applied to ductwork to enhance thermal performance and prevent condensation and dripping. Return air ducts only need to be insulated if they pass through environments that adversely affect the return air temperature. Exhaust air ducts normally do not need insulation.

Similarly, is insulating ductwork worth it? Ducts are made of sheet metal, fiberglass, or other materials. Ducts that leak heated air into unheated spaces can add hundreds of dollars a year to your heating and cooling bills, but you can reduce that loss by sealing and insulating your ducts. Insulating ducts in unconditioned spaces is usually very cost-effective.

Keeping this in consideration, what is the best insulation for ductwork?

The fiberglass duct board is by far the most effective. You can find formaldehyde-free insulation that also has an acrylic coating. This coating will help to keep the glass fibers from your airstream and excess noise from your home. You will also be able to enjoy a higher air quality.

How much does it cost to insulate ductwork?

The average duct insulation cost will be between $0.95 and $2.00 per sq. ft. installed, the cost will vary depending on a few factors which are discussed below, however r-values have the biggest impact and unsurprisingly insulation with r-values of r-3.5 are the cheaper, up to r-8.0 for the most costly.

22 Related Question Answers Found

How do you seal ductwork?

Duct joints should always be secured with #8 sheet-metal screws before seams are sealed with mastic. Sealing duct seams is messy work, so wear old clothes. The mastic is spread over duct seams with a disposable paintbrush, putty knife, or your fingers. (If you spread mastic with your fingers, wear rubber gloves.)

What is the best material for ductwork?

Galvanized steel and aluminum are the most common materials for sheet metal ducts. Aluminum in particular is relatively light and easy to install. They are also the least likely to harbor dangerous molds or growths because they have non-porous surfaces.

Is bubblewrap a good insulator?

Bubble wrap is an excellent insulator thanks to small pockets of air trapped within the bubbles. After applying bubble wrap insulation to your windowpane from the inside, tiny bubbles serve as a network of many insulating pockets filled with air.

How do you stop condensation on ductwork?


What can I do about ductwork sweating?
  1. Reduce the humidity level around your air ducts. Keep ducts spaced apart so air can flow between them.
  2. Unblock any ducts that are restricting air flow and have them cleaned regularly.
  3. Keep your air filters clean and change them regularly.
  4. Repair leaking ducts.

How do you increase airflow in ductwork?

3 Simple Ways to Improve Your Furnace's Airflow for More Comfort
  1. Unblock and clean your vents. Here's a super easy way to increase air flow.
  2. Change your filters and clean your return grill. A dirty air filter impedes air movement and makes it hard for your furnace to work efficiently.
  3. Seal leaky ductwork. Snap on some goggles and a dust mask, it's time to check out your air ducts.

Do you need attic ventilation with spray foam?

Most installations of spray foam insulation, when properly installed, act as an air barrier. When you use it instead of the fluffy stuff (fiberglass, cellulose, cotton), a house will be more airtight. That's good. Well, source reduction and separation would come first, but airtight homes need mechanical ventilation.

What is the disadvantage in having ducts in the ceiling?

Ceiling ducts cannot be used with radiant heating systems, which generate heat from the floors. Ceiling ducts are more visible than floor ducts and harder to camouflage. Since heat dispersed from ceiling ducts reaches the upper air first, the HVAC system has to work harder to push the heat lower into a room.

How do you get hot air out of your attic?

Install electric ventilators and attic fans, which remove hot air from an attic. They have thermostats that turn the fan on at a recommended preset temperature of 100-110 degrees. Alternatively, install passive vents such as gable, soffit and ridge vents, which are openings in the roof that allow hot air to escape.

Can I put insulation around heat ducts?


Air ducts typically are not insulated, creating costly heating and cooling losses. You can insulate the round air ducts serving your rooms with standard insulation batts or special-purpose duct insulation. Insulating your air ducts can save 10 percent to 30 percent on energy bills while improving comfort.

Is it normal for attic air handler to sweat?

Lack of Insulation
Not having enough insulation between an indoor air handler and the warm outside air is a common cause of sweating. When the cool air meets the warm air, condensation often occurs on the metal air handler.

Can you put HVAC in attic?

Having your HVAC system in your attic isn't dire, though you'll need to do some work to keep your air conditioner or furnace system running as efficiently as possible. The first and possibly most important thing is to make a commitment to yourself to change your HVAC filters regularly.

Can you use flex duct return air?

Re: Flex Duct on Return Air Diffusers - Yes or No? Flex duct effectively creates a tight radius elbow where it turns into the top of a diffuser. The high pressure loss is further increased because the flex fabric gathers at the inside of the throat and reduces the effective diameter.

Can you insulate an air handler?

Most come with 1/2-in. to 1-in. fiberglass insulation inside the cabinet. This insulation is supposed to prevent the air handler from sweating and condensing moisture on its exterior during warm weather. The insulation inside the air handler should also be enough to prevent major heat loss in winter months.