Refrigeration and air conditioning is used to provide cooling in an industrial and commercial setting. Principles of operation, maintenance, design, safety devices, hazards and construction are introduced and explored at a Third Class and Fourth Class level. Thermodynamics of refrigeration, refrigeration codes, properties of refrigerants, compression and absorption systems, operation, maintenance, controls and accessories, and psychometrics. A hands on refrigeration lab that includes the operation and troubleshooting of a refrigeration compression system.