A little extra time was spent in fashioning a support bracket because the bracket included with the air conditioner was very flimsy. Just slide the old one out and slide the other in to the existing window case. Submitted by: soda worton, MD USA (Saturday, May 19, 2012). There are numerous styles out there today but the window product is still one of the most recommended by quite a few home owners. However, if you intend to spend way above $500, then ensure that the cooling gadget is worth your money. Window Air Conditioner. The style of window will also affect the installation cost. //-->. Hey Joe, I’ve installed them for free to its really not a big deal. Thank You. Install Window Air Conditioner; Labor cost to install a garbage disposer? Hire the Best Window Air Conditioner Installation Pros in Cambridge, MA on HomeAdvisor. If there’s no three-prong outlet nearby, you’ll need an extension cord labeled for A/C use.