Be sure to contact John Cunningham before you contract with someone else. He's a true professional with integrity! Won't try to sell you something you don't need. Will recommend options and explain the differences -- then ask you to decide what you want to do. Also have 24-hour techs available for emergencies, which is not available from all companies.
Had our outside A/C unit repaired by them today. Correctly rewired and replaced a burned-out part (wrong one) that was installed by another company last summer. Service tech put stretch covers over his shoes, to make sure he didn't track dirt into the house. First time I've ever seen that!
HVAC Unlimited Inc.
7635-C Fullerton Road
Springfield, VA 22153
703-455-6000
http://www.hvac-unlimited.com