If you mount the A/C unit as specified by the manufacturer and then secured the bottom sash in the half open position with a broom handle cut to size, I think it would be safe. If someone tried to break in, they would quickly give up and go on to an easier target.

I have a small unit in my bedroom - just stuck in the window - and it is a lifesaver.

You could have a mini-split installed, but it is more expensive.

Here is a link that might be useful: Mini-split explained

Our kids shared a house in college that had one room we could never get adequately cooled, despite the best efforts of the HVAC techs. It didn't help that it was west facing (& the porch overhang was only about 6 ft.) and there were three computers running 24/7. Finally, dh installed a window A/C. He replaced the supplied screws with much longer ones in the base of the unit, and installed window locks above it. Because I'm a belt + suspenders type, I added wood braces on both sides, too (like the broom handle graywings suggested.)

I bought a decorative lattice screen to put in front of the window on the porch and placed several large potted plants in front of it. That way, no one driving by could see the A/C unit (preventing complaints from the HOA C&R enforcers.) Most people who came to the front door didn't realize the unit was there until after they came inside.

Hope y'all find a solution that works for you. It's miserable trying to sleep in a hot, humid bedroom.

If your house has siding (not stone or brick) and you don't mind cutting through it, you can also just cut a hole in another exterior wall and install the unit. That's a much more permanent solution that would require repair when you're through with the unit, but it could give you an option if the room has two exterior walls.

We've finally had upstairs units installed in the walls just a few weeks ago. Didn't do it for safety reasons, but for unobstructed view as well as free up the windows so that they can be opened when the weather is cool enough. Also, we are having the worst time with stink bugs, and they can get in through the smallest of openings.

Cost me about $300 for the carpenter to come in, cut the openings, install the units and trim out the siding around the units on the outside. Not bad and it's a permanent solution for us.

I think if someone wants to get into your home, they will do whatever they need to do to gain access. That's never been a worry for us, and we're situated in a secluded wooded area with few neighbors. We are well off the beaten track, so in an emergency, no one could hear me screaming unless they happened to be outside close and very to our property line.

Had to chime in. When I was in college, I dated a guy that went a little coo coo. I had an upstairs window AC. Once he climbed on the roof of the garage next door and pushed in my window AC. When I came home from work, he was waiting on me in my living room because he wanted to "talk". That was it for me. It creeped me out. I carefully broke up with him which he didn't take very well. I'm sure there are ways to install it more securely, but I was young and naive back then and didn't do it.

We've finally had upstairs units installed in the walls just a few weeks ago. Didn't do it for safety reasons, but for unobstructed view as well as free up the windows so that they can be opened when the weather is cool enough. Also, we are having the worst time with stink bugs, and they can get in through the smallest of openings.

Cost me about $300 for the carpenter to come in, cut the openings, install the units and trim out the siding around the units on the outside. Not bad and it's a permanent solution for us.

I think if someone wants to get into your home, they will do whatever they need to do to gain access. That's never been a worry for us, and we're situated in a secluded wooded area with few neighbors. We are well off the beaten track, so in an emergency, no one could hear me screaming unless they happened to be outside close and very to our property line.

Thanks, everyone. I'm guessing the mini-split graywings posted is the same as the wall units. Unfortunately I have a brick house, so I don't know if I could do that. Would I be able to keep my screen on or does the unit stick out too far? I have the darker screens and thought that might help hide it a little.

joanie - That really creeps me out too. I tend to be overly paranoid now, but I was very naive and trusting when I was young too. You're just lucky he left without doing anything else.

rockmanor - Do the long screws go into the windowframe making it harder to kick in? What kind of window locks were you able to install if the window isn't closed? I think if I could do everything you did, I would feel better? Could they still have gotten out the window in an emergency?

Have you considered a portable unit that stands on the floor?

Here's a link to Amazon with various one's.

Here is a link that might be useful: Portable a/c units

A friend of mine had a similar problem with a first-floor bedroom. They ended up getting a free-standing A/C unit, which needed to vent to the outside. The window was an old one with small panes and they just took out one pane of glass and put in a dry vent thingie and attached the vent hose to that.

A few years later, they replaced all the windows. They made an insert for one window of just a board, with a hole cut out and the vent hose attached. When the A/C wasn't in use, the board was just put on the floor and the window was closed. When it was in use, the window was opened, the board was put in place and the window was closed down on top of the edge of the board. They used window locks to prevent the window from being opened any further.

Another way to secure a partly opened window is to drill a hole through both the upper and lower sashes of the window when it is opened to the position that you want it. Make the hole big enough to put a long nail in. Then, whenever you open the window, you put the nail in both holes (the holes should not show on the outside). It's an easy way to lock the window in an open position.

Here is a link that might be useful: sample window lock

MsRose, the long screws did go through the window framing and secured the unit well. The locks were keyed, similar to to these at Home Depot (see below.) If there's no other window in the bedroom, I'd be a little concerned about the key getting misplaced.

Another thought could be to use a wireless alarm on the window, so if it's opened any more than needed for the A/C you'll be alerted.

Dh also had a portable A/C for his garage/workshop, similar to this one: http://www.homedepot.com/h_d1/N-5yc1v/R-202051352/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053 If you look at the "more views" link by the photo, you'll see how small an opening is required in comparison to traditional window units. Maybe something like this would interest you.

Here is a link that might be useful: Keyed window locks

The portable A/C is the 1st thing I looked at, but then I realized it also had to vent out the window and it's more expensive. My son's room is also very tiny, so it would take up valuable floor space. I do wonder about it being less noticeable than the window unit though. I have a feeling I would still be able to keep the screen on with it. Can I keep the screen on with the window unit?

rockmanor - When I was looking at portable A/C befores I kept reading that you had to empty something. I see the one you linked to says there's no bucket to empty, so I think I'll check into that one if I decide to go that route.

Maybe the room gets too hot but just having a room fan blowing on him, in addition to the a/c, might be enough to make him comfortable. During my hotter moments, even with our a/c on, sometimes I also need a fan blowing on me.

It would be cheaper than another a/c and no window or visibility concerns.

Laurie, re-reading your post again, your main concern is burglary.

We were burglarized when I was a teen, I was home alone and my parents were in Dallas.

They kicked in this very thick back door, busted the door jam(b), etc.

Robbers are going to break in no matter what unless you have an alarm system which includes alarms on the windows.

If they go through the trouble to take the unit out they're going to make dam sure no one is home. But they can easily enter another way too. They wouldn't dare do it during the night knowing someone is probably right there in the room.

I've read where they steal window units and leave, along with the compressors to big units outdoors.

I would get a small window unit for him and have someone secure it very well.

And if he doesn't have an oscillating fan, get him one. I have to have blowing air on me all the time at night.

hhireno - I actually just bought a really nice fan thinking it would do the trick and unfortunately it doesn't. I did check the vent :) and I feel cold air coming out, so I don't know if the room just isn't insulated well.

oakley - I know you're right. In my old neighborhood, the neighbors across the street were burglarized and they just kicked the front door in. Then they opened the garage door, backed in their truck and started loading it up. The owners had just moved in, so when I saw the truck, I thought they were unloading more stuff. Were you actually in the house when they broke in?

I think I'm going to bite the bullet and get something, but I haven't decided whether it will be the portable or window unit. There seems to be pros and cons to both, so I'm trying to read everything I can today.

camlan - I forgot to mention that I had the kind of locks you posted in my last house and forgot all about them. I think my then husband drilled holes in the frame, so they would screw into them and would be a little more secure.

How low is the bedroom window? How close to the walkway? What direction does the window face? Do you have shades/curtains that adequately block the sun? Have you considered reflective window shades or film?

Here is a link that might be useful: common HVAC problems (one room is warmer than others)

We use window A/C units in all of our upstairs bedrooms ($150/ea compared to $2500 for the mini-split).

We are not able to close the screens when our units are in.

Nor do we worry about security. People are going to get in if they want--somehow.

I like that they're removable so in the 8 months of the year that we don't use them, the view isn't obscured and they conveniently go away.

I can buy a LOT of window A/C units for the cost of a mini-split system or second heat pump.

Well, I still haven't done anything get. I checked with my HOA and I can't use a window unit. I didn't ask about the portable unit, but since I'm assuming I would be able to keep my screen on it wouldn't be a problem since it's not visible like the window unit. My mother asked me the other day if we could install one of the wall units on the wall that's between my son's room and the garage and that way I wouldn't have to cut a hole in the brick, which I have a feeling my HOA might night let me do anyway. Do you know if that's possible. For those of you that bought a wall unit, how much are they?

No longer an issue since my son is now 26 and lives in his own house. I posted this question 9 years ago.

In the summer, several folks cannot bear to measure while not it, however notwithstanding, cool air may be a trendy luxury that generally looks to freak individuals out. "We had kinds of heating for a really while before we have a tendency to ever had air-con," says Dr. Stan Cox, senior someone at The Land Institute in town, Kansas, and author of Losing Our Cool: Uncomfortable Truths concerning Our cool World. whereas heat was associate absolute necessity for individuals to measure in cold climates, Cox says, air-con is additional of a newcomer on the climate-controlled front. Mendell studied the health effects of air-con systems whereas with the U.S. Department of Energy's Lawrence Berkeley National Laboratory. not like heating systems, the method of cooling hot air creates loads of wetness and condensation, that should be channeled away, Mendell explains. What is not doubtful is air conditioning's terribly real and harmful impact on the world.