100+ Hvac Technician Interview Questions and Answers

There are several types of compressors used in HVAC systems worldwide.

• Reciprocating compressors

• Rotary compressors

• Scroll compressors

• Centrifugal compressors

• Screw compressors

• Axial compressors

• Diaphragm compressors

• Vane compressors

There are five types of compressors: reciprocating, centrifugal, rotary, screw, and scroll.

• Reciprocating compressors use pistons to compress air.

• Centrifugal compressors use a rotating impeller to create centrifugal force.

• Rotary compressors use rotating screws or vanes to compress air.

• Screw compressors use two interlocking screws to compress air.

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

There are two types of compressors: positive displacement and dynamic. Electrical troubleshooting and wiring are also important skills for HVAC technicians, with a focus on star delta wiring. Knowledge of chiller and DX units is also necessary.

• Two types of compressors: positive displacement and dynamic

• Electrical troubleshooting and wiring skills are important

• Focus on star delta wiring

• Knowledge of chiller and DX units is necessary

There are five types of compressors: Reciprocating, Centrifugal, Rotary, Screw, and Scroll.

• Reciprocating compressors use pistons to compress air.

• Centrifugal compressors use a rotating impeller to create centrifugal force.

• Rotary compressors use rotating screws or vanes to compress air.

• Screw compressors use two interlocking screws to compress air.

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

HVAC stands for Heating, Ventilation, and Air Conditioning. It refers to the technology and systems used to control indoor environmental conditions.

• HVAC is responsible for maintaining comfortable temperature, humidity, and air quality in buildings.

• It involves the installation, maintenance, and repair of heating, cooling, and ventilation systems.

• HVAC technicians work with various equipment such as furnaces, air conditioners, heat pumps, and ductwork.

• They perform tasks like tro...read more

HVAC stands for Heating, Ventilation, and Air Conditioning. It refers to the technology and systems used to control indoor environmental conditions.

• HVAC is an acronym for Heating, Ventilation, and Air Conditioning.

• It encompasses the technology and systems used to control indoor temperature, humidity, and air quality.

• Heating systems provide warmth, ventilation systems circulate and exchange air, and air conditioning systems cool and dehumidify the air.

• HVAC technicians install,...read more

Breakdowns in HVAC systems can range from minor issues to major malfunctions. Quick reaction is necessary to prevent further damage.

• Common breakdowns include faulty thermostats, clogged filters, and refrigerant leaks

• React by shutting off the system and contacting a professional technician

• Regular maintenance can prevent breakdowns and extend the lifespan of the system

Identifying maintenance risks, diagnosing faults, and repairing HVAC systems.

• Perform regular inspections to identify potential maintenance risks on HVAC equipment.

• Use diagnostic tools and techniques to identify electrical and mechanical faults in HVAC systems.

• Clean and adjust HVAC components to ensure optimal performance.

• Repair or replace faulty parts to restore functionality.

• Examples: Identifying a refrigerant leak, diagnosing a faulty thermostat, cleaning clogged air filter...read more

District cooling systems are efficient and cost-effective for cooling large areas. The main part of ETS is the thermal storage tank.

• District cooling systems are centralized systems that use chilled water to cool multiple buildings in a given area.

• They are more energy-efficient and cost-effective than individual cooling systems for each building.

• The main part of ETS (Energy Transfer Station) is the thermal storage tank, which stores chilled water for distribution to the buildi...read more

To determine if a filter is blocked, check for reduced airflow, increased energy consumption, and visible debris on the filter.

• Check for reduced airflow coming from the HVAC system

• Monitor energy consumption to see if it has increased, indicating the system is working harder due to a blocked filter

• Inspect the filter for visible debris or dirt accumulation

Maintain pressures and temperature in clean room by using HVAC systems, monitoring sensors, adjusting airflow, and conducting regular maintenance.

• Use HVAC systems to control temperature and humidity levels

• Monitor pressure differentials to ensure clean room integrity

• Adjust airflow to maintain desired conditions

• Regularly calibrate sensors and equipment

• Perform routine maintenance on HVAC systems

HVAC systems regulate indoor climate through heating, cooling, and ventilation for comfort and air quality.

• Heating: Involves systems like furnaces and heat pumps that provide warmth during cold weather.

• Ventilation: Ensures proper air exchange, using exhaust fans and duct systems to maintain air quality.

• Air Conditioning: Cools indoor spaces using refrigerants and evaporator coils to remove heat and humidity.

• Examples: Central HVAC systems for large buildings, ductless mini-spli...read more

HVAC has high pressure from the compressor to the condenser.

• High pressure is generated by the compressor and sent to the condenser.

• The pressure is typically around 300-400 PSI.

• The refrigerant then flows through the expansion valve and into the evaporator where it becomes low pressure.

• The low pressure refrigerant then returns to the compressor to start the cycle again.

The +,- temperature is the difference between the actual temperature and the desired temperature. HVAC technicians work to adjust the temperature accordingly.

• The +,- temperature is also known as the temperature differential.

• It is calculated by subtracting the desired temperature from the actual temperature.

• HVAC technicians use this measurement to adjust the heating or cooling system to achieve the desired temperature.

• For example, if the desired temperature is 72°F and the act...read more

HVAC stands for Heating, Ventilation, and Air Conditioning.

• HVAC is an acronym for Heating, Ventilation, and Air Conditioning.

• It refers to the technology used for indoor environmental comfort.

• Heating systems, ventilation systems, and air conditioning systems are all part of HVAC.

• HVAC technicians are responsible for installing, maintaining, and repairing HVAC systems.

• Examples of HVAC equipment include furnaces, air conditioners, heat pumps, and ventilation fans.

I prioritize time management and set boundaries to maintain a healthy work-life balance as an HVAC technician.

• I create a daily schedule that allocates specific hours for work and personal time, ensuring I stick to it.

• I use tools like calendars and reminders to keep track of appointments and deadlines, which helps prevent overworking.

• I communicate openly with my employer about my availability, ensuring that I don't take on more than I can handle.

• I make time for regular breaks ...read more

HVAC stands for Heating, Ventilation, and Air Conditioning.

• HVAC is an acronym for Heating, Ventilation, and Air Conditioning.

• It refers to the technology used for indoor environmental comfort.

• HVAC systems are responsible for heating, cooling, and controlling the air quality in buildings.

• Examples of HVAC equipment include furnaces, air conditioners, heat pumps, and ventilation systems.

The back pressure for refrigerant R-134a is typically around 60 psi.

• The back pressure for R-134a is usually maintained around 60 psi to ensure proper functioning of the HVAC system.

• Back pressure is the pressure in the low side of the system, which helps in the cooling process.

• Maintaining the correct back pressure is crucial for the efficiency and performance of the HVAC system.

CHW IN OUT temp difference and adaptive control alarm troubleshooting for HVAC technician.

• CHW IN OUT temp difference is the temperature difference between the chilled water entering and leaving the HVAC system.

• Adaptive control is a system that adjusts the HVAC system's output based on the current conditions.

• Alarm troubleshooting involves identifying and resolving any issues with the HVAC system's alarms.

• Examples of alarm troubleshooting include checking for faulty sensors or ...read more

Copper pipes are commonly used for HVAC systems in hospitals.

• Copper pipes are preferred due to their durability and resistance to corrosion.

• They are used for both hot and cold water supply, as well as for refrigerant lines.

• Other materials such as PVC and PEX may also be used for certain applications.

• The specific type of pipe used may vary depending on the hospital's needs and budget.

• Proper installation and maintenance of pipes is crucial to ensure safe and efficient operation...read more

Air conditioning is the process of altering the properties of air to make it more comfortable for occupants.

• Air conditioning involves cooling, heating, dehumidifying, and ventilating indoor air.

• It works by using a refrigeration cycle to remove heat and moisture from the air.

• Air conditioning systems can be central or individual units, and can be used in residential, commercial, and industrial settings.

• Examples of air conditioning systems include window units, split systems, an...read more

I would communicate with the client promptly, provide updates on the repair progress, offer alternative solutions if needed, and ensure their satisfaction.

• Communicate with the client promptly to inform them about the breakdown

• Provide regular updates on the repair progress to keep the client informed

• Offer alternative solutions or temporary fixes if the repair will take longer

• Ensure the client's satisfaction by addressing any concerns or questions they may have

Knowledge of defrost timers and heaters is essential for HVAC technicians to ensure efficient operation of refrigeration systems.

• Defrost timers control the frequency and duration of defrost cycles in refrigeration units.

• Defrost heaters melt frost buildup on evaporator coils, improving efficiency.

• Understanding the operation of these components helps in troubleshooting issues like inadequate cooling.

• For example, a malfunctioning defrost timer can lead to excessive frost buildup...read more

Preventive maintenance is important to ensure the efficient and reliable operation of HVAC systems.

• Preventive maintenance helps identify and address potential issues before they become major problems.

• Regular maintenance improves energy efficiency and reduces energy consumption.

• It extends the lifespan of HVAC equipment and reduces the need for costly repairs or replacements.

• Preventive maintenance ensures optimal indoor air quality and comfort for occupants.

• It helps comply with...read more

Different types of compressors include reciprocating, rotary, scroll, and centrifugal compressors.

• Reciprocating compressors use pistons to compress air.

• Rotary compressors use rotating mechanisms to compress air.

• Scroll compressors use spiral elements to compress air.

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

Understanding compressor over oiling is crucial for HVAC efficiency and longevity.

• Over oiling can lead to compressor flooding, causing inefficiency and potential damage.

• Symptoms of over oiling include excessive noise and reduced cooling capacity.

• Regular maintenance checks can prevent over oiling by ensuring proper oil levels.

• Example: In a scroll compressor, too much oil can obstruct the refrigerant flow.

Chemicals can be added to a chiller for descaling by following specific procedures to ensure safety and effectiveness.

• Determine the type and amount of chemical needed based on the chiller's size and condition

• Follow manufacturer's instructions for dilution ratios and mixing procedures

• Use appropriate personal protective equipment (PPE) when handling chemicals

• Ensure proper ventilation in the area where the chemicals are being added

• Flush the chiller system with water after adding...read more