I had a separate ac/heat unit installed in my sewing area that used to be the den and one bedroom. The vents were there and it was easy to have the outside unit added to make it separate from the whole house unit. I can shut the two rooms off from the rest of the house when not in use. It made my sewing time more comfortable as I can set the thermostat to be what I want it to be and not hear DH comments about freezing or heat stroke. I also had double windows installed on the outside wall for more natural light. DH kept saying the windows wouldn't work as the wall was all brick. ? He just didn't want the brick disturbed for some man reason. Anyway I had the windows installed and it is amazing the difference in light. Our electric bill lowered too. I don't need a light in there unless it's after dark.