I purchased an approx 1900 sq ft home last year in Northern California. The home is approx 5 years old. The home had only a gas furnace (Bryant 373LAV) located in the attic. During negotiations for the sale, a separate Bryant 563G AC unit was installed outside. Refrigeration lines for the AC were installed during construction of the house. The single air intake is upstairs. Closing all the vents on one floor does not help the situation in either summer or winter.
Here are my problems:
1. During summer, the first floor remains very comfortable. Oddly enough, when we first looked at the home for purchasing, it was approx 100 outside and the downstairs was cool. Remember, there was no AC installed at the time. The 2nd floor does not cool sufficiently. The 2nd floor remains somewhat warm even when the AC is turned on. The single thermostat is located downstairs in the downstairs family room.
2. The upstairs bedrooms farthest away from the AC unit receives very little air flow thru the vents. During the summer months, my son's room never cools completely. Granted, the room is above the garage but the air flow should be better.
3. During the winter, the upstairs is very warm and the downstairs remains somewhat cool when the heat is turned on.
4. It appears that 2 of the vents feeding air downstairs come from ducting feeding 2 upstairs bedrooms. For example, the ducting feeding my son's upstairs bedroom provides air to the family room downstairs.
I plan to get a few names of contractors from trusted friends and get estimates. However, I want to do my homework and get a better idea on the remedy.
I believe I need to get separate ducts run for the rooms downstairs which feed off ducts from the upstairs bedrooms. I think I would like to send virtually all the warm air downstairs during the winter. Conversely, I would like to send most of the cool air upstairs during the summer.
Do I need zone system or could I get manual dampers installed and adjust manually twice a year?
Is there any other possible solutions to consider.
Any information would be greatly appreciated.