Last year, I had Snell Heating and Air Conditioning install a high efficiently heating and air conditioning system in my house in Falls Church. The house is a small house, built in 1944, so installing air ducts was a challenge. There were a number of problems along the way, but in the end I've got a first-class system. My heating bill was 20% below 2012, even though 2013 was a much colder winter. But the big payoff is in the summertime, when it's cool in every room in the house.
This summer, the condenser coil was not working at full efficiency, and the house was warmer than it should have been. Snell came out and fixed it under warranty at no charge. I was surprised to learn that the warranty runs ten years! Overall, I'm very satisfied.