No, AC cannot run without gas. Refrigerant is used to create a cooling effect in AC units, and it needs to be filled for the AC unit to work correctly. If your AC unit is not running as well as it should, it could mean that the refrigerant levels are low and need to be topped off. At B-Cool Air Conditioning & Heating, Inc., AC tuneup is one of the multiple services we offer our clients in Orange Park, FL. We provide AC tune-ups to help keep your AC unit running at its best so you can enjoy a comfortable home all year round.