HVAC Basics for Beginners

HVAC is just moving heat around. This lesson covers the 4-stage refrigeration cycle that every air conditioner and refrigerator uses — compressor, condenser, expansion valve, evaporator — and why understanding it is the foundation of every HVAC diagnostic.

Even a perfect refrigeration cycle is useless if the air doesn't get to the rooms. This lesson covers static pressure, supply vs return, register sizing, and the airflow rules that make a system actually feel cool.

Most HVAC service calls are electrical, not refrigerant. This lesson covers contactors, capacitors, transformers, and the 24V control circuit every tech needs to read in their sleep.

EPA Section 608 is federally required to buy, handle, or recover refrigerant. There's no way around it. This lesson covers the 4 cert types, the 4-section open-book exam, and the rules every tech must know to pass.