DIY Window Exhaust Port

An exhaust port was needed for our shop to suck out fumes. My first instinct was to buy a window unit, but the units I was finding weren’t exactly what I was looking for. So, I built one! With material I already had and a few parts I purchased, I was able to build an effective, custom window unit which can be built to fit any window. Note: if you are going to use this for a laser cutter, you need to replace the vinyl exhaust tubes with aluminum tubes. The vinyl tubes can be flammable when used with laser cutters.

Tools and Materials used:

•  3/4” wood, I used MDF, but anything thick enough to fit your window will work
•  1/8” plywood for exhaust port and slide
•  Two 4” Aluminum Duct Exhaust Tube or Vinyl (I bought the vinyl kind which can be flammable if used with a laser cutter)
•  Marine Blower (fan), any 4” exhaust fan would work
•  Power Supply 12V
•  Speed Controller
•  Wood Glue
•  Super Glue
•  Nail gun
•  Trashed foam brush handle to make exhaust window slider handle
•  Double sided tape, used as a seal for exhaust

<click on the image below to download the parts with measurements for this build>


Step 1: Making the exhaust slide

First, I marked out and cut the outlines for the door, which consisted of 2 pieces: the frame and the door that slides open with 2 tabs to keep it from sliding out.

I then added a top panel with a 3.5" hole.

Next, the frame and top panel were glued together.

Once the glue was dry and clamps removed, double sided foam tape was added to act as an air tight seal.

Step 2: Making The Exhaust port

From 3/4" MDF, I cut out two 4" rings for the exhaust port and glued them together.

Rings and the base where super glued together. I used gel super glue to fill any gaps between the rings and base.

Step 3: Adding the fan & Making The Exhaust Slide

I wired the the fan and the power supply to the controller.


The fan was then screwed to the base (with enough room for adding some duct exhaust tube from the exit of the fan to the window exit hole, and make sure the fan is sucking to the exterior) and hot-glued the controller to the fan.

The exhaust port was then tacked down. You can see I added the scrap foam paint brush handle to the door to act as a handle.

Here is the final fit, and it works great! The only thing I did not consider was the height of the exhaust port; it hits the bottom of the window frame. If I would have raised the exhaust port a 1/2" it would rest on the sill. In this instance, it doesn't impede the function, so no harm done. 

The fan runs relatively quite, and with the speed controller, I can turn it on full blast or turn it on low as needed.