I'm a homeowner who likes to read. This site is awesome, but I make no bones about NOT having the technical expertise to diagnose or repair my systems. We moved into a new house in 1999 and have always had trouble cooling the second floor. It's a separate unit from the first floor (American Aire 80+ with a Concept 10 compressor 2 ton for approx 900 sqft). We had the install guys out several times and were read the riot act about changing filters (which I do the first of each month) and eventually was left with the guys telling me you can never cool the second floor. After reading a lot on this site, I had another company come out to evaluate. I was commended on the cleanliness of the system, and after thirty minutes the cooling issue was found. The system came precharged for 20 ft of line set. I have about 60 feet. No additional charging was ever done (the tech checked for leaks and found none) Once the tech charged the system, the upstairs has been cooler and the run times a lot shorter. It's tough finding a company that gives two sh&%s, but now that I've found one, I'll be happy to call them back. They took the time to show me what the temp readings were (3 degrees at the condensor before the charge, 36 after). It was nice to have someone who obviously took pride in their work and enjoyed showing me what was done and how things work. I took advice from the forum and let tech do his job and was rewarded with a cool house and his willingness to share information. Great site, and it's good to know there are people out there who care!!