Help. I live in a home with two A/C-Heat pump units that are around 15-16 years old. Since we moved in 10 years ago, we have had yearly problems with at least one of the systems or both. The outside box (condensor/compressor?) was replaced, the system would freeze, Freon would be low at least yearly, coils were replaced 3 times, the electric box on the outside part fried and finally, the compressor (or condensor) blew. Now, I know that the probable problem was that the company that did all the work must not have done the job well and the fact that freon needed to be added often was enough sign that there was a leak that needed to be fixed as well as being the cause for freezing and the eventual blow up of the unit.

Now, I have done a lot of research (no help from Consumer reports on brand names since the reliability has a lot to do with installation) and have learned several things such as (not to buy a unit too big or too small due to work amount and cycling, a variable speed may be the best option for my house and scrolling compressors may be more reliable. Also, it is important to use a qualified installer who has NATE trained technicians.

The unit that is out is a 3 ton for my upstairs and is a Carrier. I had a company (that has an excellent reputation) come measure and I was told that the 3 ton is the correct size. They service all brands however install only Ruud and Trane.

This company has informed me that the best options for my home in the South Central Texas Hill country (north of San Antonio which is humid and hot) is a Trane 16i or 19i (which has a 10 year parts & LABOR warranty) is my best bet as well as recommending the clean effects electronic Air Cleaner. I am not sold on the air cleaner idea and am confused about the 16i vs the 19i. The 16i uses the R410 A refrigerant and the 19i uses the R22 refrigerant (which I hear will be no longer used for A/C's manufactured after 2010). The difference in Seer is minimal for the two and the 16i is actually a tiny bit better in the heating efficiency but the cost is a bigger difference between the two.

I have no idea which way to go (especially if the life of one is 12-15 years and has a 10 year warranty) but can't help feel that I should go with the newer refrigerant on the 16i. Then, this brings me to another issue. I hear that Carrier was the first to use the R410 refrigerant which they named Puron and this causes me to feel that they have more experience with it and that the risk of the unit breaking down may be less. I read online by a contractor in Florida:
"Carrier comes with a 10 year parts and labor, 10 year lightning guarantee, 10 year rust through guarantee (handy in humid and salty climates), 25% guaranteed savings or carrier will pay you the difference, and 100% money-back satisfaction guarantee and in florida cfad dealer can offer a $1200 dollar instant rebate, it is not a mail in like tranes."
This makes me think that I should be shopping for a Carrier.

Please advise. My 4 kids bedrooms are upstairs and for now, they are sleeping all over the house and making a mess downstairs. I can't take this much longer but can't afford to make a wrong financial decision (especially with one going to college this August out of state... sigh).