Window air conditioning units are very handy, but they bring with them a security risk because they require the unit to be in an open window. While the units can be hard to move, they aren't the most difficult obstacle for someone determined to get into your home. There are ways to secure the window air conditioner, however; you just need to spend some extra time on installation.

Add a Cage

There are mesh and metal cages that you can bolt into the exterior wall of your home, making it nearly impossible for anyone to get in without ripping chunks of the wall out. These cages fit over the external part of the window unit and around the window frame. They allow for very good ventilation and airflow. If you install a cage, ensure the bars aren't thin enough for bolt cutters.

Block the View In

One deterrent that is very easy to do is to cover the window around the unit. It's very common to find window units placed at the bottom of the window with the glass above them left uncovered or left with maybe some thin window film. That allows people to see inside, which can tempt those looking for things to steal. Add blinds or shortened curtains to the window to thoroughly cover the view inside.

Fix All Spacers, Screws, and Caulking

Ensure all of the spacers needed to secure the unit are fixed, caulk all openings around the unit, and, for units in windows where the sash opens upward, place the top bar of the unit right next to the bottom of the raised window sash, connecting the two with screws. While these aren't huge security efforts, every little bit helps. Even the caulking will add another obstacle that someone would have to break open.

Secure the Mobile Pane

Use pin locks, thumb locks, and dowels to secure the opened window pane. You don't want anyone trying to lift it up to make it easier to remove the unit and get inside. While the screws connecting the top bar of the unit to the sash should stop a lot of that, if the screws aren't installed properly, someone could still force the sash upward.

You may want to have an air conditioning company come by both to ensure the unit is secured properly, and to evaluate the home for conversion to another type of air conditioning. It's always nice to have another working window, and using a system like a ductless mini-split or even a through-wall unit would eliminate a lot of the security hassles you're facing.