We have 2600 sq ft on the main level and 800 on the 2nd floor. To the 2nd floor, there is a staircase and with a door on the bottom floor. We have our master upstairs and don't use the room at all during the day. Also, each floor has it's own HVAC.

My question is: 1) should we keep the door in place for efficiency purposes? (we keep the upstairs warmer during the day than at night) I was told that removing the door would be best...but doesn't make sense to me... 2) what temp settings are good between the two floors? I read one person's answer saying to keep both systems at the same temp and several others advising to keep the bottom floor 2-3 degrees cooler than the second level.

Help! Our energy bill is through the roof and we are trying to save any way possible.

1 Answer 1


Leave the door - first and foremost, for fire safety, second, to keep from having all the cold air run downstairs and all the hot air run upstairs and then going nuts trying to keep any setting on either floor, especially if there isn't (would not expect with separate systems) a duct to circulate air between floors. If you have a door, you can let the lower floor warm up at night in cooling season, for instance, rather than needing to keep it "a few degrees cooler" to prevent warm air from rushing upstairs.

As for efficiency, heat or cool the part you are in when you are in it, and let it float warm in summer/cool in winter when you are not in it; just figure out how much the "lag time" is to get the place to temperature and start conditioning the space from your "warm AC" or "cool Heat" setting for when you are not there to the temperature you want it at when you are there far enough in advance so it's ready when you are.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.