I'm living in a 22 year old two story custom built home on a wooded lot in the Pacific NW. The The square footage is 3680. I purchased the house a year ago and am still learning the HVAC system. Apparently, the original owner was a HVAC specialist. Here's what I know about my system. I have two heat pumps, one is original the other was replaced in 2001. The back up is a Tagagi Flash hot water heater installed this year. The downstairs comprises approximately half the square footage and has an open floor plan with a large two story entry (about 18 feet high), an open living room/dining room and kitchen/family room combo. The downstairs has four return air vents and eleven heating/cooling vents. The downstairs thermostat is in a middle hallway and is set to 69 degrees during the day which makes the main floor comfortable. At night the thermostat is programed to drop to 65 degrees. There are two stairways front and back that lead up to three bedrooms, two baths and a large bonus room over the garage. There are a total of five return air vents and nine heating/cooling vents upstairs. The upstairs thermostat is located in a narrow hallway that separates the bonus room from the three bedroom/two bath area. There is also a door that can be closed that separates the bonus room from the rest of the upstairs. During the day the upstairs thermostat is set to 69 degrees and at night it's set to 64 degrees. Given all the venting and two independent heating/cooling systems in this house I would expect the house to be more comfortable. The master bedroom and master bathrrom are freezing and the bonus room over the garage is cool while the rest of the upstairs is comfortable, especially the hallway. I suspect the location of the large master suite and the number of windows (original double pane metal) are not helping my situation either. I have three exteriors walls, four windows and a glass door to a deck. I have had measurements of an eight degree termperature difference between the master bedrrom and the hallway where the thermostat is located. Currently all vents are open upstairs and down. I'm willing to close off the two bedrooms that aren't being used but the ceiling heating/cooling vents are very difficult to close as there are a square comerical style that have louvers that don't close all the way down. Also the noise of air pushing through a slightly closed ceiling vent is very noticable and annoying. During the day I keep the double doors to the master suite open. It helps a little bit but it is still too cool to be comfortable. At night the doors to the master suite must remain closed due my neighbor's bright outside lights which probably also contributes to the room being cold. I'm looking for any suggestions as to how to improve the comfort of the master suite and bonus room without spending a fortune. Last year my heating bills were incredibly high so I'm trying to find ways to reduce my costs of maintaing a comfortable upstairs. Any ideas?