How to Install a Duct Booster Fan to Make Your Home Even More Comfortable

There are three different types of duct booster fans. The best type for you depends on several factors, such as the size of your floor duct, if you can access the ceiling below it, and your confidence in your handy skills.

The simplest option is the booster fan that sits on top of the register. You don't need to open the floors or ceilings or install boots with this type. You may not need most of the supplies and tools on the list if you go with this option. 

Inline duct booster fans are installed in the duct line. They can have simple or incredibly complex installations. Because they can be wired into your ductwork, inline duct boosters offer the most powerful air boosts of all three options. You may need to hard-wire this fan into your furnace with a relay, which you shouldn’t attempt without a local electrician. If it’s a plug-in type like the simple booster fan, you just need to find the right duct.

Recessed duct fans are tucked inside floor ducts. You'll need to measure your floor ducts. The standard sizes are 4 by 10 inches and 4 by 12 inches. If your floor duct is smaller than this, you'll need to cut the floor with a table saw and install a right-angle boot sized to your recessed duct fan. If your recessed duct fan already fits in the floor duct, you don’t need a table saw or boot.

Assuming that your ducts are standard size, go to the room where it's too hot or cold and locate the register. 

• Simple booster fans: place the fan on top of the register, then continue to Step 4.

• Recessed duct fans: Locate the duct register, open it, and pop the booster fan into the boot. Using your screwdriver and screws, screw the booster fan into the floor. 

If the ducts are smaller than standard, use the table saw to cut an access panel and remove the duct boot. Install a right-angle boot sized to your new booster fan. This might require removing some flooring. Head to Step 4.

Locate the exhaust duct, disconnect the power, and remove the end cap. If the correct duct is connected to other segments and has no end cap, use a utility knife to cut into the aluminum tape and undo the screws along the duct's seam with the screwdriver.

Insert the inline duct booster fan into the duct, and secure it with screws or zip ties. Put the end cap back on, or replace screws on the duct seams and place new aluminum tape around the seam.

Turn the power back on if you just installed an inline duct booster fan. If your electrician hard-wired the fan, test its flow and the on-off switch they installed.

For simple booster fans and recessed duct booster fans, plug the cord into the nearest outlet. Is airflow in the room improving and feeling warmer or colder as desired? The fan shouldn’t make rattling noises if running at high speeds.

Finish the job with ultimate comfort by adding a fan speed controller to the new duct booster fan. With this controller, you can adjust it to your liking whenever you want on extreme weather days. Sweltering heat wave? Turn it up!