Ok, Im a totaly newb here and know enough about HVAC to be dangerous. Anyways, back in August of '05 my exterior compressor unit was replaced with a new Goodman 1.5 ton unit. The old one was an approximately 15 yr old Carrier. It was covered under a home warranty I had at the time. Anyways, ever since when the summer arrives (I live in AZ) my AC just does not work worth a darn. Once it gets about 100 out I have difficulty keeping my house below 80. The air handler inside is still an old Carrier. I have had the system serviced and the techs find no coolant leaks, the coolant levels are fine and the system is functioning. Even the transfer coils are clean and I am using a higher flow fiberglas air filter. Yet the AC will run non-stop from about 11am - 8 or 9pm just to keep the place at 80. My condo is 1040 sq foot and both my indoor and outdoor units are 1.5 ton. My thought is a new air handler with a similar SEER rating and a variable speed fan will rectify this problem. However several techs from several companies all give me different answers. So really what I need to know is if it is even worth replacing or not and if in fact it will help at all. Any advice would be greatly appreciated.