Quiz on Gas Defrost Piping Methods

What is the most popular method of defrost used in commercial refrigeration?

• Steam defrost

• Water defrost

• Gas defrost

• Electric defrost

Which of the following is NOT a gas defrost piping configuration?

• Reverse cycle defrost

• Liquid gas defrost

• Hot gas defrost

• Cool gas defrost

What does hot gas defrost use to complete the defrost process?

• Electric heater

• Cold refrigerant

• Hot discharge refrigerant

• Liquid nitrogen

In cool gas defrost, what is the proprietary type developed by Hussmann called?

• Koolgas

• Coolflow

• Chillgas

• Frostgas

What component is used to control the flow of gas in hot gas defrost?

• Thermostat

• Expansion valve

• Solenoid

• Compressor

What is the function of the four-way valve in reverse cycle defrost?

• To heat the evaporator

• To increase pressure

• To change refrigerant direction

• To cool the compressor

How many evaporators are typically needed to supply enough hot gas in a multiple evaporator system?

• Three

• One

• Two

• Four

What is the main purpose of a re-evaporator system?

• To cool the evaporator

• To ensure only vapor refrigerant flows back to the compressor

• To return liquid to the header

• To increase the pressure of the refrigerant

What is a key consideration when piping for gas defrost?

• Color of the pipes

• Length of the pipes

• Coefficient of linear expansion

• Cost of materials

What can thermal shock in evaporators lead to?

• Increased efficiency

• Faster defrosting

• Compressor failure

• Cracks in joints and welds