How To Install a Return Air Duct In Your Ceiling

You might be enduring inadequate heating and cooling in your home. One way to resolve this problem is to have efficient return air ducts. But you might be wondering how to go about its installation. You are on the right page! We have consulted the experts to deliver you the installation guides for your convenience.

To install a return air duct in your ceiling, you would need to determine first if you need to install a new duct or tap into existing ductwork. Anyhow, here are the steps:

  • Locate where you intend to position the return air grilles.
  • Cut a hole at the ceiling drywall and attach the plenum box.
  • Work on the return air ducts at the ceiling spaces.
  • Attach the duct to the outlet vent of the plenum box.
  • Install the air filter and attach the return air grilles.

Installing your return air duct isn’t a daunting task. You don’t need to be an HVAC expert to successfully finish the project. Stay on this page as we discuss the relevance of return air in your home’s HVAC system, the best places to install them, as well as the details of its installation.

Air condition in room, ceiling vent. How To Install a Return Air Duct In Your Ceiling

How to Install Return Air Ducts

The insulation process can be made simple. Just like any other DIY project, be sure to wear protective clothing. Also, you will need your working tools such as a nail gun, drill, and electric saw. Here are the steps:

Determine the location of the return air grilles

Locate where you intend to position the grilles for return air. Then proceed to cut through and make a hole in the ceiling drywall. Be careful not to cut any pipes or wiring that run above the drywall. The hole should be in the space between the ceiling studs.

Be sure to take precise measurements of the grille dimensions. The ceiling hole should be smaller than the grille size. This is because vent grilles come with screws or metal tabs for easy mounting. The outlet grille should snugly fit the ceiling opening. Once the hole is cut, you can test fit the grille.

Shop for this ceiling vent grille on Amazon.

There should be sufficient space above the ceiling hole for positioning the plenum box. Install the plenum box directly above the hole. The plenum box has its outlet vent where the return duct will be attached.

More often, you may need to cut out pieces of framing lumber to support the plenum box at the ceiling space. The plenum box should be secured and tightly anchored to withstand wear and tear and vibration of return airflow.

Shop for this ceiling box on Amazon.

Framed home installation of air conditioner and heating ductwork in ceiling a new home HVAC

Locate the return air ductwork

Return air ducts are usually positioned in the spaces above the ceiling. The ducts run through ceiling joists until it hovers in the area above the furnace. This is usually done during the construction phase. Nevertheless, you can still add or tap existing ductwork. Be sure to identify those ducts that carry return air to the furnace.

For return air, you can either use flexible aluminum ducts or rigid metal box-shaped ducts. For practical reasons, flex ducts are more commonly used than rigid metal ducts due to cost and ease of installation.

Shop for this flexible duct on Amazon.

Check out one of our previous posts on the use of flex ducts for return air: Can You Use Flex Ducts for Return Air?

Worker Installing an Attic Vent Duct

Install the Duct

Remove any insulation and other ceiling materials in the spaces between studs that run the route of the ductwork. Then position the new duct or connect it to existing ductwork. This could run across the ceiling, down the wall frames, crawl spaces, closet, laundry room, or toward the basement.

In this phase, you may need a metal bender tool, drive cleats, duct connectors, and metal clamps. The new duct should be installed tightly at the bottom of the ceiling joists. You can also insulate the duct with foil-faced wrap. Lastly, secure the duct to the ceiling joists with a hanger strap or saddle support.

Shop for these steel duct clamps on Amazon.

Air-conditioning Ductwork and Pipework In Commercial Building Fitout

With aluminum duct collars, securely attach the duct to the outlet vent of the plenum box. Additionally, seal all joints and seams with a duct sealant for maximum performance. With a caulking gun and paintbrush, you can do duct sealing to finish off your project.

Shop for these duct connectors on Amazon.

Install Air Filter

To complete your installation for return air, attach your HVAC filter to the outlet grille. You may then proceed to test run your installation.

Learn more about air filters in this post: "How Many Air Filters Does a House Have? [And Where are Filters Located]"

Home Room Ceiling Ventilation. Modern Interior Air Vent

Why Return Air Ducts Are Important

Return ducts have become essential components of your home’s air circulation system. In a forced-air HVAC system, return ducts have the important role of transporting the indoor air back to the furnace or the air handler unit. The siphoned air will then be circulated back to your living space through the supply ducts.

Without properly installed return air ducts, your home’s air circulation is not at its maximum efficiency. Aside from giving you discomfort and even a health risk, you might even experience an increase in your electricity bills. Over time, your home’s heating and cooling system will eventually fail.

In a nutshell, this is how air circulates in your home. Return air ducts improve airflow and even reach the remote areas of your home while at the same time increasing the efficiency of the furnace.

Return air ducts can usually be found in joist spaces at the ceiling which is directed toward the furnace. With your DIY tools, you can install them without professional help.

Where Should Return Ducts be Positioned

We list some helpful guides on the placement of return air ducts in your home.

ceiling mounted return ducts for centralized airconditioning units

Centralized Location

If you have a home with multiple bedrooms and other living spaces, you need not have a return air duct in every room. Modern designs in duct systems have only one or two return air ducts that can effectively take care of the entire home.

Make sure that one or two return air ducts are placed in a centralized location as possible.

Near the Thermostat

The rule of thumb is to install the return duct as close as possible to the thermostat. This setup enables the thermostat to monitor the temperature that is circulated back to the furnace and onwards inside your home. And typically, the thermostat is installed in a centralized location.

With the thermostat and return duct in a centralized location, the circulation and temperature readings are reflective of every part of the house. Unfortunately, this setup isn't normally done due to restrictions in the overall home design.

Yes, return air is ideally placed near the thermostat! Check it out here: How Far Should A Thermostat Be From Return Air or Furnace? 

Across the Supply Vents

An effective setup, though not required, would be that the return air ducts are located across the supply vents. The latter is usually installed near windows and doors where heat mostly enters your home.

The supply ducts are strategically installed to counter the heat loss or heat gain. When the return ducts are installed across, it will allow the system to siphon the air throughout the space.

To learn more about air blowing through vents, we have this post for you: "How Hot Should the Air from my Furnace Be?"

Not in Bathrooms and Kitchen

You should avoid placing return air ducts in bathrooms and kitchens. Of course, you would not want the foul smell and humidity of the bathroom to be circulating in the whole house. Similarly, the cooking odors and moisture from the kitchen are also unpleasant to go with air circulation in your home.

A cooling vent register on the wall of a home, with lever. How To Install a Return Air Duct In Your Ceiling

Final Thoughts

Return air is essential for your home's air circulation. Installing return air ducts can enhance indoor air quality, lower energy bills, and improve the efficiency of your furnace. Having one or two return air ducts is sufficient even if you have multiple bedrooms and living spaces.

It is recommended that you position your return air vents near the thermostat if you have a centralized system. Also, it would be best if placed across the supply vents so that air will circulate throughout the entire room. For practical reasons, never place return air vents in the bathroom and kitchen.

Begin your installation by locating where you intend to place your outlet vents, whether you will make a new duct or tap existing ductwork, and also what duct material to use. The installation steps can be another DIY project. You don't need to be an HVAC expert!


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