2 Refrigeration Fundamentals and Environmental Responsibility Free Online FlashCards

What does a refrigerant do?

A refrigerant is a fluid that circulates through a sealed system, absorbing heat in one place and releasing it elsewhere.

What happens in the evaporator?

The low-pressure refrigerant absorbs heat from the refrigerated space and boils into vapor.

What does the compressor do?

The compressor draws in refrigerant vapor and raises its pressure and temperature.

What happens in the condenser?

The hot, high-pressure refrigerant releases heat to the surrounding air and condenses into liquid.

What does the expansion device do?

It lowers the liquid refrigerant’s pressure as it enters the evaporator, reducing its temperature so it can absorb heat again.

Does a refrigeration cycle create cold?

The cycle moves heat from one place to another; it does not create cold.

How can refrigerants differ environmentally and in safety?

Older CFCs and HCFCs can deplete stratospheric ozone; many HFCs do not deplete ozone but can be powerful greenhouse gases. Some alternatives have lower climate impact but may be flammable.

What are possible clues of a refrigerant leak or system fault?

Declining cooling, unusually long compressor operation, oily residue near a joint, or damaged tubing can be clues. They are not proof because other faults can cause similar symptoms.

What should you avoid if a refrigerant leak is suspected?

Do not puncture tubing, add refrigerant instead of finding the problem, or intentionally release refrigerant. Identify the refrigerant from the appliance label and follow appropriate service procedures.

What qualifies as a small appliance under EPA Section 608?

It is factory-manufactured, charged, and hermetically sealed, with 5 pounds or less of refrigerant. Small size alone does not qualify an appliance.

When is EPA Section 608 Type I certification generally required?

A person who services or repairs a small appliance and could reasonably be expected to compromise its refrigerant circuit generally needs EPA Section 608 Type I certification.

What federal recovery methods apply before opening or disposing of a small appliance?

With certified equipment: recover 80% using equipment made before November 15, 1993; with newer equipment, recover 90% if the compressor works or 80% if it does not. Alternatively, evacuate to 4 inches of mercury vacuum.