I live in north Florida in a 1492sqft one story house built in 94. I have a Carrier split heat pump system. I work from home and like the temp to be set at 73-74. During the summer days the AC runs non-stop and the temp still climbs to 78-80. I have lived in the house 7+ years, and had every inch of the AC checked and cleaned, windows tinted, and personally examined every inch of duct work for leaks. All the companies/people who have looked at it say the unit is undersized for the house, and I need to go to a 3ton unit to maintain the temp I want. The air handler is located near the center of the house. It is a Carrier FB4ANF030, R22, with a piston size of 70 which matches the outside condenser. The blower motor has 3 speeds that can be hardwired. I went from medium speed to high in an effort to try to cool better. Did not help. On top of all of this energy cost have skyrocketed, and my bill was over $400 last month with only 2 people living in the house.
1. I know just having the outside unit upgraded to a 3 ton could lead to the inner coil freezing. However would having the blower still on high and a addition of a TXV on the coiling coil prevent that?
2. If it would still freeze, can I just upgrade to a 3ton coil that would still fit in my current air handler?
3. Is it worth just upgrading to a TXV valve for energy savings and or any enhanced cooling?
4. Can the compressor just be replaced with a far more efficient one without replacing the whole outside unit?
5. If the only way is to upgrade to a complete new unit, will I need all new duct work as well? Currently there is only one main return, and no individual return to each room, per new home construction specifications.
6. Has any ever heard of replacing a Central AC unit with a Mini Split system like LG's Art Cool? I really like the idea of controlling AC temp in each room.
I apologize if my lack of understanding has lead me to ask some very wrong or crazy questions.