Choose a vertical-sliding window that is close to a three-prong outlet, and ensure that the windowsill is not damaged or rotten. Prepare the necessary screws to attach the mounting hardware on the windowsill or outer wall, and prepare the AC unit for installation.
Prepare a measuring tape, level, flat-head screwdriver, level, angle brackets and scissors. Electric drill, screws and wood may also be needed. After choosing a suitable vertical-sliding window, measure the window opening’s width to determine the appropriate size of the window AC. Fix the windowsill if it is damaged.
Use the given screws to attach mounting hardware on the windowsill, ensuring the window AC is locked into place. Read the manufacturer’s manual for exact instructions. Use the required number of brackets, and use a level to ensure proper installation.
Install the built-in extension panels that come with the AC unit, and slide the AC into the window opening, positioning it into the mounts. Ask for help from another person if the air conditioner is too heavy. Once the AC unit is locked into place, secure it by closing the window. Fill gaps between the air conditioner and the window frame by sliding out the accordion panels. Use foam insulation strips to fill gaps between the air conditioner and window, and put a thick strip of foam between the lower and upper sashes.