QA

How To Insulate Ductwork In Basement

Does ductwork need to be insulated in basement?

The answer to the question of, “Should I insulate the ductwork in my basement?” is…. Maybe. 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 put insulation around ductwork?

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.

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.

Can I use flex duct in basement?

Ideally, all ducts should be located within the conditioned space. This is typically the case for ducts that run through a dropped ceiling or soffit, or between joists, so long as the floor system sits on top of a conditioned basement or crawlspace.

What type of insulation is used for ductwork?

The most common material used for insulating heating and cooling ducts is fiberglass. Fiberglass duct insulation is available in various thicknesses and R-values and in either a flexible or rigid form.

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 R-value do I need for ductwork?

R-value of 3.5 is required for buried ductwork and ducts installed in an unvented attic with roof insulation or in an unconditioned space (including both ventilated and unventilated crawlspaces). There are no R-value requirements for ductwork installed in an indirectly conditioned space.

Why is insulation required for ductwork?

In general, all air ducts should be insulated: to provide noise control, to save energy and, where necessary, to prevent condensation. Condensation control is always required when the temperature in the room through which the duct runs is higher than that of the cooled air in the duct.

Can you put fiberglass insulation around ductwork?

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.

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.

Is air duct sealing worth it?

The importance of HVAC duct sealing can’t be overstated. Having your HVAC duct-work tested and properly sealed is one of the home improvements with the highest payback. Duct sealing can lower your heating and cooling costs by 15%, 20% or more.

How do you prevent ductwork from condensation?

Wrapping your AC ductwork is an effective way to prevent condensation. Duct wrap has a foam insulation inner layer and a foil outer layer. Cleanly wrap it around the AC duct and fasten with duct tape near the joints.

How do you insulate air ducts?

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.

Is insulating a basement ceiling worth it?

Insulating the basement ceiling will keep most of the heat upstairs in the living space. As a result, the basement will be colder in the winter making it important to also insulate any water pipes or heating/cooling ducts in the basement.

How do you cover exposed ductwork?

If the ducts are easily reachable, consider covering them in flexible, magnetic sheeting. The magnetic sheets are solid, glossy colors that wrap around and conceal the ducts. They are easily removed if you want to change the color or look of the room.

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.

What is the disadvantage of flex duct?

The downside of flex ducting is that it is considered temporary with an acknowledged lifespan of only about 15 years. Another major disadvantage is that they are a little too flexible, so they are often incorrectly installed. And with greater friction than metal ducts, proper sizing is critical.

Can I replace metal duct with flexible?

Metal duct can still be found in many older homes, but flexible duct is more prevalent in newer homes. Both work well. Still, should you decide to change from metal to flexible duct, don’t waste money on an HVAC contractor. It’s a time-consuming job, but definitely one you can do yourself.

What is the max recommended length of flexible duct?

Flexible air connectors which are listed to UL 181 are allowed by the standard in lengths up to 14 feet. This product is specifically evaluated for the maximum length up to 14 feet, and the manufacturer’s installation instructions are reviewed to ensure proper installation up to this length.