I built a house two years ago and installed a Goodman furnace and condenser. I believe it is a 3-ton unit with a 45 foot line set. The first year it seemed to cool great. Last summer is started running longer and longer to keep the house cool, eventually running all day without keeping house at the thermostat setting of 80F. I called an HVAC professional to look at the unit. He came out, hooked up his gauges, said the coolant was okay but could use a little more, and added a couple of psi of coolant to the system and stood around smoking cigarettes and watching his thermometer for an hour before charging me $150. Performance after his visit did not change at all. The weather started cooling off and I put off any more action until this year. The system still cools but is not nearly as good as the first year the system was installed. My in-laws have a home next door with the exact same floor plan and HVAC system and it works much better than mine. Their AC will keep the house cool and still cycle on even the hottest days. I don't want to call another HVAC Tech out if he is just going to do the same thing as the last one. What else could be the cause of the reduced efficiency? The line from the condenser feels cool when the system is running. The compressor does come on. I have a quick read thermometer and a gauge set to check the system temps and pressures if I need to.