Complete HVAC Fundamentals Course By Zebra Learnings

Explore how heat transfers from hotter to cooler objects, and how HVAC professionals control conduction, convection, and radiation using proper materials, air flow, and refrigerant flow.

Explore evaporation, boiling point, and condensation in a closed container, as heat turns liquid water into vapor at 100°C, reaches saturation temperature, and returns to liquid via condensation.

Explore how refrigerants absorb heat to cool air, from early chilled water in cooling coils to ammonia in the first mechanical air conditioner, and learn about R-12 and R-22.

Trace the history of refrigerants from ammonia to R-12 and HFCs, understand ozone depletion, and follow the shift toward low-GWP and natural refrigerants for safer, greener HVAC.

A refrigerant absorbs heat from the indoor air and boils into vapor, then releases heat outside as it condenses and cycles back via the expansion valve and compressor.

Explore the refrigeration cycle, the four parts—compressor, condenser, expansion valve, evaporator—and how indoor and outdoor coils transfer heat from room air to the refrigerant.

Explain how low evaporator pressure makes the refrigerant boil indoors at about 3.3°C, while high condenser pressure raises its condensation temperature to about 51°C, enabling condensation against 35°C outside.

Learn the fundamentals of superheat and subcooling in an HVAC system, measuring vapor and liquid temperatures to protect the compressor and optimize condenser and expansion valve performance.

Diagnose air conditioning systems using five readings: superheat, subcooling, suction and discharge pressures, and compressor amps, with an interactive tool to identify faults like airflow issues and charge problems.

Explore the compressor, the heart of the hvac system, which compresses refrigerant to high-pressure vapor and sends it to the condenser, covering reciprocating, rotary, scroll, screw, and centrifugal types.

Examine the capillary tube, a metering device in the refrigeration cycle that uses friction to drop refrigerant pressure from condenser to evaporator, for constant-load appliances like refrigerators and freezers.

Explore how the thermal expansion valve (txv) reduces refrigerant pressure by passing high pressure refrigerant through a tiny passage, causing a temperature drop and controlled flow to protect the compressor.

Learn how the electronic expansion valve uses a stepper motor, temperature sensor, and pressure transducer to precisely regulate refrigerant flow based on superheat.

Learn how the accumulator protects the compressor by ensuring only refrigerant vapor enters the suction line, while liquid refrigerant collects and slowly returns, preventing liquid slugging.

Discover how a filter dryer protects HVAC refrigeration systems by removing moisture, acid, and solid contaminants, and learn its construction, types, warning signs, and maintenance.

Learn how the sight glass visualizes refrigerant flow and moisture, helping technicians detect low charge, contamination, or restrictions and decide when to verify with superheat and subcooling.

Learn how the high and low pressure switches safeguard the air conditioning compressor by cutting power when discharge or suction pressures go out of range.

Discover how the service valve provides controlled access to the sealed refrigerant system, enabling charging, recovery, vacuuming, use of gauges, and isolating the indoor and outdoor units.

Explain how a chiller plant cools buildings by circulating chilled water to AHUs and back, and contrast water-cooled systems with cooling towers to air-cooled condenser coils and fans.

Learn how a water-cooled chiller uses a cooling tower and a seven-component loop to transfer heat from water to refrigerant through a shell-and-tube evaporator, with higher efficiency but more maintenance.

Compare cross-flow and counter-flow cooling towers, detailing air-water flow and the impact on efficiency. Describe chemical dosing, blow-down, make-up water, and equalizer lines that preserve water levels for continuous cooling.

Adding more lessons, with upcoming modules on chiller plants, beams, heat load, and electrical; stay connected by turning on Udemy notifications and rating the course.