How to Install Window Air Conditioners in Anderson Windows

by Mary Lougee ; Updated September 19, 2017

Window air condtioners cool small to large areas depending on their cooling capacity.

window air conditioner image by Aaron Kohr from

Items you will need

  • Measuring tape
  • Carpenter’s pencil
  • Drill with screw bit
  • Scissors

Window air conditioners come in a range of sizes to cool very small to large rooms. These air conditioners install in an existing window so there is no need to cut a hole in the wall for them to fit. Installation includes opening and supporting an Anderson window, installing the cabinet and sliding the air conditioner into the cabinet.

Step 1

Measure the window width with a measuring tape. Divide the width by two and mark the center of the opening with a carpenter’s pencil on the windowsill.

Step 2

Unscrew any screws holding the front grill on the air conditioner. Pull the grill straight out of the air conditioner.

Step 3

Remove the screws on the side of the air conditioner cabinet. Slide the air conditioner unit out of the cabinet toward the front of the cabinet.

Step 4

Measure and mark the center of the air conditioner width with a carpenter’s pencil.

Step 5

Open the Anderson window completely. Place the cabinet in the window aligning the center marks on the unit and the windowsill. Hold the cabinet in place with one hand and close the window with the other hand. The window sash should fit into the top of the cabinet frame.

Step 6

Pull the unit's left curtain out to touch the side of the window frame on the left. Insert screws into the curtain and drive them into the frame with a drill. Repeat this process to install the right curtain.

Step 7

Place the sill support in front of the cabinet and screw it to the sill. Turn the adjusting bolt clockwise to raise the front of the cabinet 1/2-inch taller than the rear.

Step 8

Slide the air conditioner into the cabinet.

Step 9

Measure, mark and cut the foam insulation strip to the window width. Tuck the foam in between the crack of the top fixed window portion and the sliding bottom portion.

Step 10

Place the left and right window locking brackets on each side of the air conditioner. Screw each into the window sash with their screws.

Step 11

Place the front grille on the unit and attach screws on each side to secure it. Slide the air conditioner filter into the front slot of the grille.

Step 12

Plug the air conditioner into an electrical outlet.


  • Some air conditioning units do not have the side curtains attached upon purchase. Install one curtain on each side of the air conditioner with the screws provided.

    Not all air conditioners include locking brackets to secure the window from opening from the outside. Locking brackets keep homes secure so that intruders cannot pull the window containing an air conditioner up, push the unit out or in and gain access to a home.

    Hardware and home improvement stores sell air conditioning accessories for installation.


  • A second person may be necessary to slide the unit out and back into the cabinet if the unit is large.

Photo Credits

  • window air conditioner image by Aaron Kohr from

About the Author

Mary Lougee has been writing for over 10 years. She holds a Bachelor's Degree with a major in Management and a double minor in accounting and computer science. She loves writing about careers for busy families as well as family oriented planning, meals and activities for all ages.