
Window Air Conditioner Security
During the summer months, window AC security is important.
A burglar could get into your home through a window after pushing in the air conditioner on the 1st-floor. Or the burglar might just steal it!
When the weather warms up, it’s time to install your window air conditioners. But they can become a target for burglars.
Here’s what you can do about it:
Most window air conditioners are installed and simply held in place by gravity. It’s tucked behind the window sash which keeps it from falling out. Maybe there’s a small screw holding the top rail and a few on the side for the accordion side-panels.
Many people don’t even install a single support screw into the top rail because the air conditioner is held in place by gravity and its downward force against the window sash. Good enough, right?
So, what can you do to better secure your window air-conditioner?
UPDATE: Read on for several up-to-date suggestions!
Screw Top Mounting Rail Window AC unit into Sash
At least install a screw through the air-conditioner’s top mounting rail into the window sash. Most window air conditioners include a drilled-out hole in the top center to accommodate this.
Consider drilling additional holes through the same top mounting rail to accommodate more screws into the lower window sash (see illustration below).

Install Security Window Lock for your Portable Air Conditioner
A convenient window lock for air conditioner security: (Sliding Window Lock, Window Stop, Window Restrict)
A window lock will prevent or deter the burglar from pushing and forcing up the window.
The AC unit may be screwed to the sash, but if the window itself isn’t locked it’s still possible to force open and reach in and shove the air conditioner. Install window frame locks to prevent this.
Security Window Lock
For Vinyl Windows – you might consider this popular window lock as seen here.

Window Security Wedge
Another clever idea is a window wedge, like this one –

Window Air Conditioner Security Bars
This adjustable window security bar is designed to fit between the window and the top frame to prevent it from opening when a portable AC is installed.
It fits into that relatively short gap. My own air conditioner happens to leave a gap of 8-1/2″ inches when it’s installed.
This particular air conditioner security window lock wedge adjusts from 7-3/4″ to 14-3/8″ in height. Measure your window (with AC installed) to make sure it fits. You can check it out here.

‘Do It Yourself’ Window Security Bar:
While the air conditioner is mounted in the window, measure the distance from top of the lower window frame to the very top of the double-hung frame itself (with AC installed). Cut a wooden dowel to snugly fit – which can be wedged to prohibit the window from opening further…
Window Air Conditioner Bracket
It’s also a good idea to get a window air conditioner bracket. It makes it harder for the burglar to get the air conditioner out from the outside.
( Here’s a line-up of choices to look at. )
Stick-on Window Alarm
Here’s a great product that will absolutely deter a would-be burglar.
The second they begin to force open the window, this cleverly designed window alarm will alert (based on motion/vibration sensing).
It simply ‘sticks’ onto the window, inside. Small, only about 3″ diameter. It has an ‘on/off’ switch for your convenience when opening the window yourself…

Stick-on Burglar Alarm Security Window Sticker Decal
Deterrence! On the window with the air conditioner, stick on a home security window decal where it will be plainly visible.
This alone may be enough to prevent a break-in as the burglar may move along to an easier target.

Window AC Accordion Side Panels
Depending on the width of the window air conditioner, the ‘accordion’ side panels may be extended fairly wide, or maybe not. This is an obvious weak point of entry for a burglar to punch through and gain leverage to shoving the air conditioner itself.
While the aforementioned suggestions will slow down or deter a burglar (likely to the extent of giving up without attracting attention), you might consider to (do it yourself) build wooden side panels to replace the plastic ‘accordion’ panels.
Window Air Conditioner Security Tips
Ultimately, you are not going to stop a determined burglar, but you will probably stop the majority of amateur burglars who are looking for quick and easy entry.
If one of them happens to pick your home because they see a window air-conditioner hanging out of a 1st-floor window, when given a hard push and it doesn’t budge, they will probably move on.
If the burglar pulls or pushes on the air conditioner while attempting to lift the window sash, it will not readily come if you’ve taken the precautions mentioned above.
Burglar Proof Tips
Okay, maybe more accurately stated, burglar resistant…
Tip: Consider removing any 1st-floor window air-conditioners when going on an extended vacation. A few minutes effort may be worth it…
Tip: You could plant thorny bushes… rose bushes, blackberry bushes etc. just below your windows…
Replace the side panels with plywood between the sash and jamb.
A wire cage to cover the outside of the AC unit.
Amazon Recommends this Air Conditioner:
Perfect for a bedroom, a small room, great reviews:
Have it shipped right to your door: FRIGIDAIRE

[ Read: 3 Ways A Burglar Breaks In, 80 Percent Of The Time ]
[ Read: 7 Mistakes That Burglars Love You To Make… ]
[ Read: 10 Tips For Better Home Security ]
Good stuff
Agree!
Been there done that : )
My window was a slider v up/down. I did lock myself out, couldn’t find the spare key that was in the bush and so thought that I could get in without doing any damage. Wrong.
The ac unit hit the floor before I could react. Put a pretty good dent in it but didn’t damage the window. After that, seeing how easy it was I did a better job of bolting it down.
I found a latch that you can attach to the top window that has a wedge shaped cover that can be opened flat to open the window the full way. With the cover in place, it limits the travel of the upper & lower windows to whatever height you install it at (I did 4″).
I know Anderson has an expensive version of the same thing on Amazon, but the inexpensive version at WallyWorld had done the job find for me.
Hope this makes sense, will try to find a link…..
Found it on Amazon:
Defender Security U 9929 Double Hung Wood Window Flip Lock
I’ve updated this article for the 2020 season – Window AC security for portable air conditioners. The article has been popular in search-engine-land, so if you have further suggestions – let’s hear them…
Unfortunately, we have those casement windows that crank out sideways. I wouldn’t mind having just one or two window units so we wouldn’t have to run the whole house AC. I did find out there are small stand alone units for individual rooms. Might try one of those. And they are on wheels, so you can move them from room to room. They look like a tall room air purifier.
DJ5280,
I have one of those stand alone units for the few times it gets unbearably hot here. It definitely helps. One thing to be aware of that you might have to find a work around for. These are portable in the sense that you can roll them anywhere, but, they must be vented to the outside when in use. The venting set-up is geared for double hung windows – adjustable sliding sides with a hole for the vent tube to attach to. I don’t see how that would work with a casement window. If you knew where you wanted it, and were handy in the carpentry area, you could always create your own venting to outside.
I had purchased two of those roll-around AC units several years ago when we were renting an A-frame home during an interim 2 year period prior to landing at our current AO. Regular portable window AC wouldn’t fit the crank-out casement windows. Regarding the venting for the roll-around units, I had to build it (plywood) to fit a given window. It wasn’t terribly difficult, but it was the only way for it to install and function properly.
Believe it or not, thieves will even steal a big Central Air unit for the copper it contains. I recall living in Orlando Fl. about 15 years ago and the City planted a bunch of new trees along the I-4 interstate. Later that week (2 am) they caught a gang digging them up to resell. Yes, window units say, ” Please steal me!, or break in for even better stuff”.
My point is, folks will steal anything. Example: DW sold medical equipment (Pulse Oyx’s) in south Florida. The medical students/ future Doctors used to steal $3,000 pieces of equipment from the Operating rooms at night so they didn’t have to buy them when they opened their own practices.
S.W.
One of the nice things about the portable inside units is the only thing possibly visible from outside is the vent opening – nothing sticks out. For less visibility, one could vent from a window/side of the house that is more hidden from public view.
Gee, didn’t even know that about the venting issue. Thanks all. Guess we’ll stick with the central air. Good thing it’s been a cool spring and haven’t needed it yet. Got enough on my plate right now…..