Installing an Energy Star-rated window air conditioner is an economical way to beat the summer heat.

Step 1: Measure the room that you want to install the air conditioner in and choose a window with an outlet nearby. Many room-sized air conditioners will work in a standard 120v 15amp outlet, assuming there are not too many additional appliances running off the same circuit. If possible, install a GFCI outlet in place of the existing one.

Step 2: Remove the screen and measure the window where the conditioner will be installed.

Step 3: Choose an air conditioner that is big enough to cool the room, small enough to fit in the designated window and wired appropriately to plug into the existing electrical outlet.

Step 4: Remove the air conditioner from its packaging and follow the manufacturer’s assembly instructions. This will typically include mounting a bracket on top of the unit and installing accordion-style panels on either side of the housing.

Step 5: With a friend’s help, carefully place the air conditioner into the window opening. The bottom of the conditioner should sit flush with the window sill. Depending on the window style, it may be necessary to wedge a length of wood between the sill and the air unit.

Step 6: Close the window down behind the top bracket and use a level to ensure the air conditioner is angled slightly from front to back to facilitate condensation runoff.

Step 7: Secure the top sash in place with frame locks or angle brackets. Pre-drill screw holes to avoid splitting the wood.

Step 8: Open and secure the accordion panels on either side of the unit.

Step 9: Fill gaps between the sashes and around the air unit with appropriately sized insulation. Additional foam panels can be installed in front of the accordion panels for added efficiency.

Step 10: From outside, hook up a drain line or situate a bucket to capture condensation from the air conditioner. Captured water can be used daily to water plants.

Step 11: Use a combination of clear weather seal tape, foil insulation and weather stripping to seal all gaps around the air conditioner and window outside. Place a strip of tape along the bottom of the window and the top of the air conditioner to seal out moisture.

Step 12: Plug in the unit, turn it on, adjust the air flow and enjoy.