How to Feed an AC Line Set Through a Soffit Vent

Venting your air conditioning line through a soffit vent will help keep your home cooler. Follow this procedure to feed your AC line through a soffit vent.

Step 1: Choose the Soffit Vent Location

Put the soffit vent on the shadiest side of your house, to keep warm outdoor air out of the attic.

Step 2: Cut the Soffit Vent Hole

Make the soffit vent hole as small as possible. The air conditioning line will measure less than 1 inch in diameter and have a flange support for the vent.

Step 3: Measure from the AC Unit to the Soffit Vent

Measure the shortest, most vertical distance from the AC Unit to the soffit vent. Draw the path with a red marker. Minimize bends and flats in the AC line.

Step 4: Feed the AC Line

Feed the AC line along the path and out to the vent, where an assistant will grab it.

Step 5: Secure the Soffit Vent Opening

Fasten the AC line's support flange into the soffit vent with galvanized screws. Fit and trim the vent mesh. Fasten the vent mesh to the opening with galvanized screws, to keep out squirrels and insects.