Free online courseRefrigeration and air-conditioning

Course Description

Refrigeration and air-conditioning sit behind everyday comfort, safe food storage, clean indoor air, and reliable industrial processes. This free online course builds a clear understanding of how cooling is produced, how it is measured, and how real systems are designed to deliver performance efficiently and safely. You will revisit essential thermodynamics and then connect those principles directly to the devices and cycles used in modern refrigeration and HVAC applications.

The course guides you from core refrigeration concepts into air and aircraft refrigeration cycles, showing how temperature and pressure changes translate into usable cooling. As you progress, you will learn how the vapour compression system operates beyond the idealized models, why compressor protection matters, and how cycle changes affect capacity and efficiency. You will also become comfortable interpreting P-h charts, a key tool for translating operating conditions into decisions in troubleshooting and performance evaluation.

Real installations rarely match simplified textbook assumptions, so you will explore practical enhancements such as compound compression with intercooling, multi-evaporator arrangements, and cascade approaches used when different temperatures or improved efficiency are required. The course also introduces refrigerants from a functional and environmental perspective, helping you understand what makes a working fluid suitable in terms of safety, stability, and reduced environmental impact, and why those tradeoffs matter in professional practice.

On the air-conditioning side, you will move from the purpose and features of AC systems to the behavior of moist air and the use of the psychrometric chart. You will practice reasoning about psychrometric processes, air mixing, and infiltration, and see how outdoor conditions and building effects influence system performance. The course ties these ideas to design conditions and cooling load concepts, giving you the mindset needed to estimate demand and avoid common sizing and comfort problems.

To round out the HVAC picture, you will examine air distribution fundamentals, duct effects on velocity and noise, and system-level choices such as chilled water configurations in large applications. Finally, the course connects engineering decisions to people by covering human physiology, thermal comfort targets, and indoor environmental health, including ventilation strategies that support comfort while improving air quality. With frequent practice questions and problem-solving, you will leave better prepared to discuss HVAC concepts confidently and apply them to maintenance, operations, and entry-level engineering tasks.