Hi all. Yet another question. We currently have a split-level home that was built in the 1970's. My youngest daughter's room, which is on the extreme northwest corner of the house, is always about 10-15 degrees colder than the rest of the house. The vent is open all the way, there's warm air coming out, but it's consistently much colder. The return and the thermostat are right outside in the hallway, and all the other rooms stay at the right temperature pretty much. I do keep her door shut at night, to keep the cats out. Could that be causing the problem? I also know that the northwest corner is traditionally cooler, but this seems excessive. Is the heat just not circulating right or what? Is there anything I can do besides use our space heater in there?