20+ AC and Refrigeration Technician Interview Questions and Answers

Refrigeration is the process of removing heat from a confined space, while air conditioning involves both cooling and heating of air in a space.

• Refrigeration is mainly focused on removing heat from a space to lower the temperature, typically used in preserving food or creating cold storage.

• Air conditioning involves both cooling and heating of air to maintain a comfortable temperature in a space, commonly used in homes, offices, and vehicles.

• Refrigeration systems typically hav...read more

There are several types of refrigerants used in air conditioning systems, each with different properties and environmental impacts.

• Common refrigerants include R-22, R-410A, and R-134a

• Refrigerants can be classified as CFCs, HCFCs, HFCs, and natural refrigerants

• Newer refrigerants like R-32 and R-1234yf are being developed to replace older, more harmful ones

I recommend a split system air conditioning system for its efficiency and flexibility.

• Split system ACs are energy efficient and provide better temperature control.

• They are versatile and can be installed in different rooms or zones.

• Split systems are quieter compared to window units.

• Examples: Mitsubishi Electric split system, Daikin split system.

There are three types of conditioners: air cooler conditioner, water cooler conditioner, and evaporator conditioner.

• Air cooler conditioner is used to cool the air in a room or space.

• Water cooler conditioner is used to cool water for various purposes.

• Evaporator conditioner is a type of air conditioner that uses evaporation to cool the air.

A shell and tube type condenser is a heat exchanger used in HVAC systems to transfer heat from the refrigerant gas to the cooling water or air.

• Consists of a series of tubes through which the refrigerant flows, surrounded by a shell through which the cooling medium flows

• Efficient in transferring heat due to large surface area provided by the tubes

• Commonly used in air conditioning systems and refrigeration units

• Examples include water-cooled condensers in large commercial HVAC s...read more

Knowledge of air conditioning and refrigeration repair is essential for maintaining efficient and functional cooling systems.

• Understanding the refrigeration cycle: This includes knowledge of components like compressors, condensers, and evaporators.

• Troubleshooting skills: Ability to diagnose issues such as refrigerant leaks or electrical failures.

• Familiarity with tools: Proficiency in using tools like multimeters, pressure gauges, and vacuum pumps.

• Safety protocols: Knowledge o...read more

Yes, I would suggest a person to purchase a product if it meets their needs and is of good quality.

• Consider the person's specific needs and requirements

• Ensure the product is of good quality and meets safety standards

• Provide information on the benefits and features of the product

• Offer recommendations based on personal experience or expertise

Avoprator is used in air conditioning and refrigeration systems to control the flow of refrigerant.

• Avoprator is used in air conditioning systems to regulate the flow of refrigerant through the system.

• It helps in controlling the temperature and pressure of the refrigerant in the system.

• Avoprator is commonly found in commercial and industrial HVAC systems.

• Examples of Avoprator brands include Emerson, Danfoss, and Sporlan.

AC units typically range from 1 to 5 tons, with larger systems available for commercial use.

• Residential AC units usually range from 1.5 to 5 tons.

• A 1-ton AC unit can cool approximately 400-600 square feet.

• Commercial systems can exceed 20 tons for larger spaces.

• The tonnage of an AC unit refers to its cooling capacity, not its weight.

There are mainly four types of compressors: reciprocating, rotary, scroll, and centrifugal.

• Reciprocating compressors use pistons to compress the refrigerant.

• Rotary compressors use rotating vanes or blades to compress the refrigerant.

• Scroll compressors use two spiral-shaped scrolls to compress the refrigerant.

• Centrifugal compressors use a rotating impeller to compress the refrigerant.

Thermoset is a type of polymer that undergoes a chemical reaction during curing, resulting in a hard and rigid material.

• Thermoset polymers are formed by cross-linking polymer chains through a curing process.

• Once cured, thermoset materials cannot be melted or reshaped.

• Examples of thermoset materials include epoxy, phenolic, and melamine.

• Thermoset materials are commonly used in electrical insulation, automotive parts, and construction materials.

Product diagnosis can be both easy and hard, depending on the complexity of the issue and the technician's experience.

• Experience matters: A seasoned technician can quickly identify common issues, like a refrigerant leak.

• Complex systems: Advanced HVAC systems may require extensive troubleshooting, making diagnosis harder.

• Tools and technology: Using diagnostic tools can simplify the process, such as multimeters for electrical issues.

• Documentation: Access to manuals and schemati...read more

A condenser is a device used in HVAC systems to release heat absorbed by the refrigerant during the cooling process.

• Converts high-pressure gas into high-pressure liquid

• Located outside the building

• Uses a fan to help dissipate heat

• Can be air-cooled or water-cooled

R134 gas is used as a refrigerant in air conditioning and refrigeration systems.

• R134 gas is a type of refrigerant used in AC and refrigeration systems.

• It is a hydrofluorocarbon (HFC) with the chemical formula CF3CH2F.

• R134 gas is non-toxic and non-flammable, making it a safer option for cooling systems.

• It is commonly used as a replacement for R12 refrigerant, which is being phased out due to its ozone-depleting properties.

AC full name in Hindi is 'एयर कंडीशनिंग' (Air Conditioning)

• AC stands for 'Air Conditioning' in English

• In Hindi, AC is translated as 'एयर कंडीशनिंग'

• एयर कंडीशनिंग is commonly used in India to refer to air conditioning systems

A compressor is a mechanical device that increases the pressure of a gas by reducing its volume.

• Compressors are commonly used in air conditioning and refrigeration systems to circulate refrigerant.

• They work by taking in low-pressure gas and compressing it to a higher pressure.

• There are different types of compressors, such as reciprocating, rotary, and scroll compressors.

• Compressors play a crucial role in the cooling process by transferring heat from inside a space to the outs...read more

There are various types of refrigerators available for different needs and preferences.

• Top freezer refrigerator

• Bottom freezer refrigerator

• Side-by-side refrigerator

• French door refrigerator

• Compact refrigerator

• Built-in refrigerator

• Counter-depth refrigerator

Diagnosing and fixing refrigerator defects involves identifying issues like temperature fluctuations, noise, and leaks.

• Check the thermostat settings; ensure it's set to the desired temperature.

• Inspect the condenser coils for dirt buildup; clean them if necessary.

• Examine the door seals for any gaps or damage; replace if needed.

• Listen for unusual noises; a failing compressor may indicate a need for replacement.

• Look for refrigerant leaks; use a leak detector to find and repair a...read more

Refrigeration cycle is a process in which refrigerant absorbs heat from the indoor air and releases it outside to cool the indoor space.

• Refrigerant absorbs heat from the indoor air through the evaporator coil.

• The refrigerant then flows to the compressor where it is compressed into a high-pressure, high-temperature gas.

• The hot gas then moves to the condenser coil where it releases heat to the outside air and condenses into a liquid.

• The liquid refrigerant then flows back to the...read more

Types of compressors include reciprocating, rotary, scroll, and centrifugal.

• Reciprocating compressors use pistons to compress refrigerant gas.

• Rotary compressors use rotating vanes or blades to compress gas.

• Scroll compressors use spiral-shaped scrolls to compress gas.

• Centrifugal compressors use high-speed rotating impellers to compress gas.

• Examples: Copeland Scroll Compressor, Danfoss Reciprocating Compressor, Hitachi Rotary Compressor

Types of condensors include air-cooled, water-cooled, evaporative, and hybrid condensors.

• Air-cooled condensors use air to remove heat from the refrigerant.

• Water-cooled condensors use water to remove heat from the refrigerant.

• Evaporative condensors use a combination of air and water to remove heat from the refrigerant.

• Hybrid condensors combine features of air-cooled and water-cooled condensors.

Operator refers to a person or system that controls machinery or equipment, ensuring proper functioning and maintenance.

• Operators are responsible for starting, stopping, and monitoring equipment.

• They perform routine maintenance checks to ensure optimal performance.

• For example, an HVAC operator checks refrigerant levels and system pressures.

• Operators must understand safety protocols to prevent accidents.

• They often troubleshoot issues and coordinate repairs with technicians.

Refrigerant is a substance used in cooling systems to absorb and release heat, enabling refrigeration and air conditioning processes.

• Refrigerants can be gases or liquids at room temperature.

• Common refrigerants include R-22, R-410A, and R-134A.

• They work by evaporating and condensing in the refrigeration cycle.

• Refrigerants must have low boiling points to efficiently absorb heat.

• Environmental regulations have led to the phase-out of some harmful refrigerants.

A chiller is a machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle.

• Chillers are commonly used in air conditioning systems to cool buildings or industrial processes.

• They work by transferring heat from the liquid being chilled to a different liquid or to the air.

• Chillers can be air-cooled, water-cooled, or evaporatively cooled.

• Examples of chillers include centrifugal chillers, screw chillers, and absorption chillers.