I recently purchased a new home with a bonus room above the garage. I was very happy when I purchased the home to find out it had a 3 zone heating and cooling unit. The problem I have is the AC in the bonus room zone runs alot even during spring and fall when it's not that hot outside. I have investigated the insulation and it looks good. I was planning on letting this go one more summer but when the energy company sent out a flyer saying they are going to raise the rates during the summer months I decided to make this a higher priority.
Could this be caused by what I have read about as radiant heat? If so what could I do to fix this problem? I have read about an seen on some HGTV shows that closed cell spray foam insulation fixes this problem but don't know if this really works. I also found online that a foil faced insulation will reflect radiant heat. Has anyone tried either of these if so which one works or if both work which one works better?