Foam insulation boards which can be purchased for cheap at any local hardware store are great for this purpose.
How to insulate around doors and windows.
Then fill in the gaps in insulation with foam which will seal around the window.
Install window insulation panels.
Another solution to dealing with a drafty air conditioner is to replace your wall or window unit with an hvac system.
Weatherstrips are an inexpensive way to help seal drafty doors and windows.
Do not use one that has bleach in it.
Mount the aluminum frame of the window to the interior side of your window.
Each frame has weatherstripping around the perimeter and that weatherstripping should seal the existing window.
Foams made of hfc or propane propellants are excellent choices.
This guide from lowes can help you knock out.
Simply cut the boards to size and fit them in place.
You can buy a kit from your home improvement center to do this with or order one from the internet however make sure the foam is for around windows.
When you purchase a window panel kit you should get all the necessary components and specific installation instructions.
With the insulation on the inside of the 2 bys right moisture from inside air can condense on cool 2 bys if the insulation isn t sealed properly possibly leading to rot.
Expanding foam insulation works best around doors.
Typically there is little room for insulation between the doorjamb and frame much too little room for typical fiberglass insulation.
Apply rigid foam insulation and foil.