Here is the senario: Cape code with a finished second story. The house has forced air (oil) and no central A/C. The second story has three rooms (small) and a bathroom (small, too). Two of the bedrooms and the bathroom has vents. the vents seems to have been installed in the cheap because they are connected to the main duct in the basement at perpendicular angles. The third bedroom has no vents. There is no return on the second floor.
During the winter, the furnance does supply heat to the rooms upstairs and if I am at the bottom of my stairs (on the main floor) I can feel the cold air coming down due to the return on the main floor, so the second floor is not bad in the winter (except the bedroom with no vent - it can get cold in there on really cold days)
I want to install central A/C. I've been told many different options:
1) "The second story will cool down, but will be humid because there is no return installed up there - you can buy an air handler and a second central A/C just for that floor"
2) "Just use window A/Cs"
3) "It'll be fine"
4) "It'll be fine, but you might need a dehumidier"
5) "Use ductless on the second story"
6) "Fix your ducts"
I'd say your asking for opinions, more then testing our knowledge.
I'm sure most if not all have seen units in your situation.
I would do what ever it takes to get return air upstairs, If you use it much at all. Or suffer the effects as they are.
You say you feel cold air falling down the steps now, wait till you run the a/c. Cold air will fall to the first floor even with r/a up stairs. But the return air will pull the hot air back to be conditioned.
I would get vents in the room that doesn't have any at this time, that means return as well.
I wouldn't use window units, unless you own stock with your electrical supplier. Central a/c is cheaper and more controlled if done correctly.
Thanks, Toolpusher. And will a return help during the winter season as well?
Yes, it helps to keep areas more uniform in all seasons.