QA

How To Insulate Rectangular Ductwork

Is insulating ductwork worth it?

The answer to the question of, “Should I insulate the ductwork in my basement?” is…. While insulating basement ductwork will, in fact, reduce energy loss from your ducts, thereby lowering the time your system has to run to properly cool or heat your house, it will also tend to make your basement cooler.

Can you insulate ductwork with foam board?

In contrast, rigid foam board not only provides the structure for the ductwork system, but it functions as insulation and vapor barrier, too. The finished duct is airtight, waterproof and sound-resistant. Polyurethane boards are easier to install than metal ductwork.

Can insulation touch heating ducts?

Fiberglass insulation can touch HVAC ductwork provided the ducts are not leaking or forming too much condensation. The insulation should be snug enough to prevent significant gaps throughout the ductwork.

Which insulating material is used in ductwork?

Fiberglass is the most common insulation material for HVAC ducts. Flexible ducts are always insulated by fiberglass material. Fiberglass insulations have a layer of shiny aluminium foil on the outer surface to hold the fiberglass material together.

Does exposed ductwork need to be insulated?

A: Depending on the climate and the ducts’ location, it may not be necessary to insulate them. The ducts are exposed to the same cold, heat and humidity that exist on the outside. Insulating them is essential in colder climates, optional in milder ones and necessary in humid climates to prevent condensation.

What type of insulation do you use to wrap ductwork?

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.

Does ductwork need to be insulated in conditioned space?

No insulation is required for ducts in conditioned space. In some areas of the country, conditioned crawlspaces and attics may need to meet specific code requirements. Several PATH Field Evaluations and other projects evaluated the cost and effect on trades of bringing ductwork into conditioned space.

What do you do about condensation on ductwork?

Try to reduce the humidity level in the air near the air ducts. You can go for a dehumidifier if that helps to reduce the condensation. Unblock any ducts that are restricting airflow and have them cleaned regularly. Regularly clean your air filters and change them once every three months.

Is insulated ducting better?

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.

Can I use great stuff around heating ducts?

The same heating, vacuum and air conditioning systems that make a home comfortable create penetrations that can cause drafts, forcing appliances to work harder. The air stops here with Great Stuff™ and Great Stuff Pro™ Foam Sealants.

Is duct board still used?

Basically, the fiberglass absorbs moisture and provides a breeding ground for mold spores. Therefore, duct board should only be used where it will not be exposed to damp conditions. Both systems have been used for years and, when installed appropriately, will give good service.

How do you make a Ductboard plenum?

Slit the foil vapor barrier extending beyond the edges of the duct board with a duct board knife. Fold the ends of the foil onto the outside of the duct board. Staple the foil to the duct board. Tape the flaps down with foil tape to complete the duct board plenum.

Can heating ducts touch drywall?

Drywalls cannot touch ductwork. But, you can install drywall directly against the ductwork with a 6-inch gap. Make sure to give a 6-inch gap between drywall and ductwork.

Can insulation go around dryer vent?

Whether you should insulate your dryer vent or not depends on its location. If the dryer duct is within the home or a heated basement, there is no need or reason to insulate the duct/vent pipe. However, if the dryer duct runs through an unheated basement or crawlspace—insulation is highly recommended.

Which type of insulation is most effective?

Fiberglass Insulation. Fiberglass is the most common insulation used in modern times. Because of how it is made, by effectively weaving fine strands of glass into an insulation material, fiberglass is able to minimize heat transfer.

Can you use Reflectix on ductwork?

Ease of handling and quick installation make Reflectix® the first choice when selecting insulation for round or rectangular ductwork in HVAC systems. The product provides an R-8.0 when installed with a 0.75” air gap between the duct and the insulation, and R-6.0 when installed direct to the duct without a spacer.

When should ductwork be insulated?

The ductwork in unconditioned areas, such as basements, floors, and ceilings is where ductwork insulation is most necessary. Cool air passing through warm areas in your home can cause condensation in the ductwork. This condensation leads to moisture buildup inside the enclosed space of the duct system.

Is round ductwork better than rectangular?

Round air ducts are best suited for high-pressure HVAC systems. Their design creates less friction, allowing air to flow easier throughout the building. Rectangular ducts aren’t as efficient with their airflow, which means they can create more harm than good in a high-pressure system.