we are in a pretty bad situation but have to cope with it. Our studio is only about 10 feet high, no AC. there is a steel construction on the ceiling so we won't have any problems with attaching light but the problem is that the suspension of many lights is to tall so the lights are then eventually hanging at a height of 7 feet. In a situation where we use a couch and people are seated this is not a porblem but we can't actually have anybody standing in the studio. Can you name me manufacturers of reasonable gear we could use?
It seems like an obvious chioce would be fluorescent. As far as heat, nothing comes close.
I do understand about your height issue. We have a Studio that is hung with 10' truss. So after the lights go in with adapters it can hang low. You can do some tweaking of the clamps/adapters to choke up as much as possible. Other than that, location of the talent, camera, and ligths would need to be adjusted to make sure they are out of the shot.
Any room without AC that you are using as a Studio, will always be a problem. But I'm sure you knew that.