Industry Competency Exam ICE Light

Industry Competency Exam (ICE) Light Commercial HVAC Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which type of refrigerant is most commonly used in light commercial

HVAC systems today?

A. R-22

B. R-410A

• R-134a

D. R-12

R-410A is widely used in modern light commercial HVAC systems due to its efficiency and lower ozone depletion potential compared to R- 22.

• What is the purpose of a TXV (Thermostatic Expansion Valve) in a

refrigeration system? 1 / 4

• Increase compressor efficiency
• Regulate the flow of refrigerant into the evaporator
• Reduce condenser pressure
• Heat the air in winter

A TXV controls refrigerant flow to the evaporator to ensure proper superheat and efficient heat transfer.

3. In a direct expansion (DX) cooling system, the evaporator is located:

• After the condenser
• Inside the air handler
• In the compressor
• Outside the building

The DX evaporator is inside the air handler or indoor unit, where it absorbs heat from the conditioned air.

• What is the primary purpose of a condenser in an HVAC system?
• Cool the air
• Increase refrigerant pressure
• Reject heat from the refrigerant to the environment
• Filter indoor air

The condenser removes heat from the refrigerant, allowing it to condense from a gas to a liquid.

• Which type of compressor is commonly used in light commercial

rooftop units?

• Scroll 2 / 4

• Reciprocating
• Screw
• Scroll

Scroll compressors are preferred for light commercial systems due to their reliability, efficiency, and low vibration.

• What is the typical pressure range for a medium-temperature R-410A

system evaporator?

• 10-50 psi
• 60-100 psi
• 110-145 psi
• 200-250 psi

R-410A operates at higher pressures than older refrigerants; medium-temperature evaporators usually run around 110-145 psi.

• What is superheat in a refrigeration system?
• The temperature of refrigerant in the condenser
• The heat added to the compressor
• The temperature of refrigerant vapor above its saturation

temperature

• The difference between ambient air and return air

Superheat is measured at the evaporator outlet to ensure no liquid refrigerant enters the compressor.

• Which safety device protects the compressor from overpressure in the

discharge line? 3 / 4

• Low-pressure switch
• High-pressure switch

C. TXV

• Expansion valve

A high-pressure switch shuts off the compressor if discharge pressure exceeds safe limits, preventing damage.

• Which airflow problem can cause icing on the evaporator coil?
• Low refrigerant charge
• Restricted airflow
• Dirty condenser coil
• High outdoor temperature

Restricted airflow reduces heat transfer at the evaporator, causing the coil to drop below freezing and ice to form.

• In light commercial HVAC, what is the main function of a

economizer?

• Reduce refrigerant pressure
• Use outside air for free cooling when conditions allow
• Increase indoor humidity
• Protect compressors

Economizers reduce energy costs by using cool outside air to assist or replace mechanical cooling.

• What is the typical efficiency rating used for light commercial

rooftop units?

• / 4