My house is mostly one level but has a bonus room over the garage. The garage is uninsulated with drywall. The bonus room and the garage both face west and get the afternoon sun. The bonus room and attic are well insulated, and the west-facing window in the bonus room has that reflective window film professionally applied.
Still, the bonus room runs about 5 to 10 degrees hotter than the downstairs. I live on the downstairs and my son lives in the bonus room, which makes it hard to agree on a temperature for the thermostat. Comfortable for him is cold for me, comfortable for me is hot for him.
Options I'm considering:
1. Ductless mini-split. I know these work well and are expensive.
2. Roof ridge vent. Not very expensive, seems like it would help.
3. Dual zone AC. Existing single zone HVAC is in the garage.
4. Attic fan with a thermostat. Attic has vents on the north, south, and west facing sides.
5. Increased roof vents. Attic already has the appropriate number of roof vents, but maybe more would help.
The roof shingles are regular three tab asphalt shingles. Roof is original to the 2004 home. Tentative plan is to replace the roof shingles in the next few years.
Thanks for any input / thoughts / opinions.