At heart, we're a local company and we always have been. Just because One Hour Heating & Air Conditioning trucks can be seen from coast to coast, that doesn't mean OUR focus lies anywhere other than Delaware, Pennsylvania, and Maryland. When Chris Lenhard founded our company in 1991, his goal was simple: provide top-notch HVAC services and complete satisfaction to his friends and neighbors. He called his company Calvert Heating & Cooling. In 1995, Chris teamed with David Murray to expand the reach of his company and bring the same premier service to a larger customer base.