What can be done about the stuffy, humid feeling I get, especially on mild, cloudy days?

  a. If you are getting ready to replace your system you should consider the XL19i system. It was designed to address this issue directly. There’s none better.
b. Replace your current thermostat with a Trane XT300, XT302 or XT500 thermostat. They have the very effective Comfort-R® feature built-in.
c. Avoid oversizing your system.
d. If none of the above are chosen, lower your thermostat setting during these periods.