How to make a return HVAC supplies box

HVAC supplies box
High key view of an airport gate with a set of industrial air conditioning heat pump on the foreground.

How To Install An HVAC Supplies Box:

Step 1:Modeling The Important Dimensions

The rectangle component represents the air filters, while the circular part represents the metal start collar (which will be added later).

I used a type of Styrofoam. This type is commonly known as blue foam board.

Step 2: Filling In The Mold And Getting Things Started

To make a seamless transition, always use thin foam. To construct it, I used gorilla glue, which foams up and fills and sands easily.

You can also contact HVAC Cleaning Duluth GA for professional help.

Step 3: Smoothing The Contours

To fill up all of the irregularities and create smooth shapes for the airflow, I utilized drywall mud. The less energy needed, the easier the air moves.

Step 4: Add A Layer Of Protection

Always protect the resin in the fiberglass process by latex paint. Without a barrier, the resin will soon disintegrate the Styrofoam plug.

A minor pinhole in the barrier will cause a huge space in the foam plug. Eventually, it causes hours of work to be lost. To ensure that each coat covers the preceding one, stagger paint coats with contrasting colors.

Step 5: Let The Resin Dry

I didn’t go into how to fiberglass the plug because it is a separate topic. After that, chip away all the foam. Then clean it off with acetone after you have set the fiberglass. Most importantly, sand the entire interior, as airflow is smoother on a flat surface. Lastly, install an 18″ metal start collar along with a few thicknesses of fiberglass to keep it secure.

Step 6: Begin Painting The Inside Of The House

To achieve a smooth surface on the inside, use high-quality automotive paint.

Step 7: Add Insulation To The Exterior

You can skip this step if you are going to insulate the outer fiberglass. Therefore, I didn’t spend much time on it.

Step 8: Checking For A Good Fit

To make a snug fit, you need to adjust the ceiling joists.

How To Install An Air Filter:

We did a lot of research on the internet and discovered that having enough return air filter area is a typical concern in most residential HVAC setups. Moreover, we wanted to make certain that our setup would not be harmed as a result. Additionally,  we ran the numbers and discovered that we needed a 3.5-tonne packaging unit. Moreover, contact Air Duct Cleaning Duluth GA. They provide the best services in the town.

  1. I designed two 20 × 20 return filters, totaling 800 square feet of filter area (700 sq in is the recommended). My attic space is very cramped because of the 3-12 pitch of my roof. Moreover, the supply ducting filled it entirely, leaving little room for the return ducting. Making a custom return duct, boot, and filter holder was the best solution.
  2. Starting with a foundation and a 19″ circle to symbolize the “in” and “out” of the duct, I constructed a foam mock-up of the inside of the duct. I used non–beaded blue foam.
  3. You need to place these first two pieces of foam in position in the attic area. After that, link them after the air handler. In my case, I have mounted an air handler on the roof with the plenum in place. Then I went back to the shop and filled in the perimeter with foam.
  4. After that, I used drywall mud to fill up the surface flaws. Moving further, I applied two coats of latex paint to protect it against the vinyl ester resin used in the fiberglass process.
  5. When I was building it, I used fiberglass mat cloth. I used Six inches thick cloth weighing about 25 pounds and 2 liters of vinyl ester resin. I scraped the foam out and painted the inside to provide a flat surface for airflow when the resin cured.

Where Should Return Ducts Be Installed?

You may believe that because the goal of a return duct is to pull air back into the system, it should be situated directly across from the supply vents. This is partially true and partially false. Yes, this is an effective configuration, but it does not have to be done in this manner.

Mounting a return duct in each room with a supply vent is certainly possible, but it isn’t always the ideal option. In fact, it’s best to avoid putting return ducts in bathrooms or kitchens when installing them. The heating and air system would simply circulate cooking scents and moisture throughout the system as a result of this. This would be a tragedy waiting to happen, as well as a source of foul odors.

Whenever it applies to two-story homes, things can get a little more complicated, but the basic guideline is to put the return as close to the thermostat as feasible. The thermostat will be capable of monitoring and recording the temperature that is being transported back through the system if you follow this basic rule. Furthermore, the thermostat is typically put in a central location.

By centralizing the thermostat and return duct, you’ll be able to collect data on circulation and temperature from all areas of the house. Unfortunately, this may not be the best option for many types of homes. In these instances, installing returns in every room of the house excluding the bathrooms and kitchen may be absolutely necessary.


In conclusion, we can say that installing an HVAC supplies box is an easy process. One can easily install supplies box at home.

Read Also: What’s The Most Common Use For Membrane Filter Plates

Be the first to comment

Leave a Reply

Your email address will not be published.