I am replacing an ancient central ac unit. What is the best brand to go with? I am looking for energy efficiency and reliability. Am cooling and heating 1400 sq.ft. I am not going dual zone. Thanks

Actually all brands work well and they all offer various efficiency's (SEER Rates) that will save you $$$ on your utility bill BUT you will need someone who is local to you to do a manual J to calculate your exact size of unit you need.

The exact size unit for your home along with a QUALITY install will assure you of a long lasting system. See the attached link below to help you pick your contractor.