Trade Introduction, Safety and Health

1. Introduction to Refrigeration and Air Conditioning (RAC)
Refrigeration and Air Conditioning (RAC) is the process of removing heat from a space to lower its temperature and maintain comfort or preserve goods. It is used in homes, industries, automobiles, and commercial applications.
History of Refrigeration & Air Conditioning
- 1748: William Cullen demonstrated artificial cooling.
- 1834: Jacob Perkins built the first working vapor compression refrigeration system.
- 1851: John Gorrie developed an air refrigeration machine.
- 1876: Carl von Linde invented the first practical refrigeration system using ammonia.
- 1902: Willis Carrier invented modern air conditioning for humidity control.
- 1930s: Freon (CFCs) replaced toxic refrigerants like ammonia.
- 1990s-Present: HFCs and eco-friendly refrigerants developed to replace CFCs.

General Safety Precautions in Refrigeration & Air Conditioning Work
- Safety is crucial when working with refrigeration and air conditioning systems, as they involve electricity, high-pressure gases, and hazardous chemicals.
Personal Safety Measures
- ✔ Wear protective gear: Safety gloves, goggles, and shoes.
  ✔ Avoid direct contact with refrigerants: Can cause frostbite or toxicity.
  ✔ Handle tools carefully: Avoid accidents while using sharp tools.
  ✔ Ensure proper ventilation: Prevents asphyxiation from leaked refrigerants.
Electrical Safety
- ✔ Turn off power before working on electrical components.
  ✔ Use insulated tools to avoid electric shock.
  ✔ Check for loose wires and damaged insulation.
Refrigerant Handling Safety
- ✔ Store refrigerant cylinders upright to prevent leakage.
  ✔ Use a leak detector before charging or servicing systems.
  ✔ Never mix different refrigerants, as it can cause chemical reactions.
Pressure Safety
- ✔ Never overcharge a system beyond its capacity.
  ✔ Use pressure gauges to monitor system pressure.
  ✔ Release pressure slowly while servicing systems.
Fire Safety
- ✔ Do not smoke near refrigerants; some are highly flammable.
  ✔ Keep a fire extinguisher nearby when working with electrical systems.

First Aid in Refrigeration & Air Conditioning Work

Injury Type	First Aid Procedure
Frostbite (from refrigerant leaks)	Warm the affected area gradually, avoid direct heat. Seek medical help.
Electric Shock	Turn off power, separate person from the source using a non-conductive object. Perform CPR if needed.
Refrigerant Inhalation	Move the person to fresh air, provide oxygen if breathing is difficult.
Burns (from hot components)	Cool with cold water, cover with a clean cloth, and avoid breaking blisters.
Eye Injury (from refrigerant or debris)	Rinse with clean water for 15 minutes and seek medical attention.

Refrigeration Tools, Instruments & Equipment

Tool Name	Function	Use
Manifold Gauge Set	Measures pressure	Checking refrigerant pressure
Vacuum Pump	Removes air & moisture	System evacuation
Refrigerant Recovery Unit	Recovers refrigerant safely	Used during repairs & disposal
Leak Detector	Detects refrigerant leaks	Ensures system safety
Thermometer	Measures temperature	Checking cooling efficiency
Charging Scale	Weighs refrigerant charge	Ensures accurate refrigerant filling
Pipe Cutter & Bender	Cuts & bends copper pipes	Used in installation & repairs
Flaring & Swaging Tools	Expands pipe ends for fittings	Used in tubing connections
Multimeter	Measures voltage, current, and resistance	Checks electrical components
Clamp Meter	Measures current without disconnecting wires	Used for compressor testing

Uses & Applications of Refrigeration & Air Conditioning
✔ Domestic Refrigeration – Used in household refrigerators & freezers.
✔ Commercial Refrigeration – Used in supermarkets, restaurants, & cold storage.
✔ Industrial Refrigeration – Used in food processing, pharmaceuticals, and chemical industries.
✔ Air Conditioning – Used in homes, offices, cars, and hospitals.
✔ Transport Refrigeration – Used in trucks, ships, and rail transport for perishable goods.