My central A/C gave up the ghost. My A/C guy suggested Janitrol or York because those are the brands he carries. He said they are the same except for cost. Hmmmm. Other people on this thread seem to have mixed feelings about Janitrol. Surfing the "Net" many sites state that no one can guess the size needed for an air conditioner. A good HVAC specialist will measure the house and figure it out. I can't imagine the calculations are easy or intuitive. How many people would truly be qualified to figure out the perfect tonnage required for a home?