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.