Home Automated Windows

I was sure this already existed. However, searches on the major home automation sites did not turn up any hits.

The idea is automated windows.

Whenever we turn our AC on or off, we need to run around our house like headless chickens closing or opening all of the windows.

An automated thermostat control could judge the exterior and humidity and based on user preferences decide if the AC should be on, the AC should be off and the windows closed, or if the AC should be off and the windows open. A signal would then open or close the windows.

Now the first thought I had is, perhaps these aren't sold as a solution because a lot of older windows can be a bit tough to open. Maybe stuck windows makes this too unreliable. But then I realize, if you are going to be dumping money into a home automation solution, it would not that much of an additional cost to replace the window tracks and fix the windows up.

So what are the best ways to go about making a window that could open and close by itself? Ultimately I think you would need to play around with a bunch of different ideas and decide which one has the best mix of reliability, low cost, and ease to install.

However it seems that there are a couple of general categories that would bear investigation:
Hydraulics/pneumatics - They could be attached to the top of the frame and pull the window up, or be embedded in the wall beneath the frame and push the window up.
Cable with motor - A cable or cables would attach to the top of the window and go up to the top of the frame. A motor could wind up the cable and pull the window up. This option seems like the easiest to install in an existing home as it could just be bolted into the top of a window frame.
Teeth and gears - If the side of the window was covered in 'teeth'  and there where powered gears in the frame, they could push the window up or down. This seems like perhaps the best option, except for a few problems. One, it requires space on either side of the window to be free for installing the necessary parts. Two, it seems like the one most prone to injury if a finger was caught in the teeth.

Tying this into one of my previous ideas, it seems like if it was combined with Integrated Window Fans it could create the ultimate automated climate controlled home.

Perhaps getting this to work would be expensive. But home automation is already expensive. I am just shocked that the major home automation companies do not offer a solution already.