I have central air in my house and the unit and everything is about 20 y/o. I realize it should be updated but I have no control over that.
The problem I have is that if I set the thermostat to to 70 degrees fahrenheit, then the downstairs stays about 70. But the upstairs will be anywhere from 76-80, depending on the room and how hot it is outside. So the problem is that people complain that it's too cold downstairs and too hot upstairs. Ideally, I would like it to be about
76-78 downstairs and about 74 upstairs.Why does this happen and is it normal? I know that a lot of air blows out in the vents downstairs and not a lot blows out upstairs. I shut off all the vents that aren't needed and close the doors to rooms that aren't used. I have the fan set to "auto". I don't know if leaving it on auto is better than setting it to "on". I don't like to mess with it because it seems to cause problems with it.
Any opinions or suggestions (other than buy a new unit)?