I have a 1,200 sqft home. I have a Lennox system. I'm not sure of the ton but the furnace is 65K BTU and it's a r-22 system. It's not cooling that well that is the system is taking a very long time to get to the target temp and it's cycling on and off (compressor). I think it's a little low on refridgerant. I called a couple service people in the area and their starting price is for 1 - 3 ounces of refridgerant then they charge by the ounce after it gets past 3 ounces. My question is that is 1 -3 ounces a big deal??? In past experiences if a system is low how much is it low by?