How to Install a Diffuser (Video)

diffuser installation

If you are looking for a how to install a diffuser tutorial guide, you are in the right place. When you perform a diffuser installation in your existing HVAC system, you will need a few tools and parts. You obviously need an air diffuser with dampers to control the flow of air.

What You Need for the Project

You need a marker to trace the diffuser into the HVAC ducting so that you know where to cut into the line. Then you need snips or some other type of cutting tool to create the opening in the duct. Check out the video and the steps below on how to take care to protect yourself from sharp pieces of duct.

As you will see, Phil uses a cutting bit in order to create the first hole and then does the rest with the snips. A power drill will make the project go more quickly, but you can use a manual screwdriver to secure the damper blade to the diffuser housing.

Diffuser Installation Steps

The video covers all of this (except the one missing step #4), but this gives you a quick reference overview to the basic steps involved in the process:

diffuser installation
  1. Place the diffuser where you want to install it into the existing ductwork, then trace it.
  2. Use a cutting bit to create a hole in the ductwork.
  3. Use snips to cut out the traced dimensions (be careful not to cut yourself).
  4. The video doesn't show this step, but you want to use the 4 pre-drilled holes in those holes in the diffuser housing and some Malco Zip-In Screws (probably the HW8X3/4) to attach the housing to the ductwork, no need for tape or glue
  5. Install the blade into the diffuser housing.

The most important tip that I can offer you is to be very careful when you cut into the ducting. It's very common to nick a finger on one of those sharp edges, and this kind of injury will bleed a lot. Also, you can end up with a lot worse than a bloody finger, so just take extra precaution by wearing gloves (unlike Phil) and taking your time on the project.

Knowing how to install a diffuser housing and blades will allow you to create the ideal installation in your home, whether you are making an addition or finishing a basement or attic. Check out this Shoemaker USR52-SC 16" X 8" diffuser or browse through the other fun resources here.