[t951]

So we have been living in our house for 10years and bought it new. The AC unit is now 10years old. (I was told this is a typical lifespan of an AC unit). Our house is rather large (3000sq feet) and it has only one AC zone which drives us nuts.
Since we live in FL our AC is used heavily. We both work out of the house and at night we like it cool.

So my questions are:

How long does an AC unit last?
How do you know its going bad?
Are there good brands and bad ones? (We have a Carrier now).
Is there a way to add a zone just for our bedroom?
How much should I be prepared to spend?
What SEER rating is the minimum or maximum I should get.

Thanks!

t.