Air Conditioning Flashcards

What condition is indicated when a technician measures frost forming uniformly across the entire evaporator coil surface?

Answer: Low airflow across the coil

Uniform frost across the entire evaporator typically indicates insufficient airflow, causing the coil temperature to drop below 32°F across its full face.

Which refrigerant replaced R-22 as the standard for residential air conditioning in the United States?

Answer: R-410A

R-410A (sold under brand names like Puron) became the replacement for R-22 in residential AC systems due to its zero ozone depletion potential.

What is the function of a crankcase heater on a compressor?

Answer: Prevent refrigerant migration and dilution of oil during the off cycle

A crankcase heater keeps the compressor oil warm during the off cycle to prevent liquid refrigerant from migrating into the crankcase and diluting the lubricant.

A technician measures a temperature split of 14°F across the evaporator (return air 75°F, supply air 61°F). What does this suggest?

Answer: Normal operation for a properly sized system

A temperature split of 14-22°F across the evaporator coil is generally considered normal for a properly operating air conditioning system.

What is the purpose of the filter-drier in an air conditioning system?

Answer: Remove moisture and contaminants from the refrigerant

The filter-drier removes moisture (which can cause acid and freeze-ups) and solid contaminants from the refrigerant circuit.

Which EPA section governs the handling and recovery of refrigerants?

Answer: Section 608

EPA Section 608 regulates the servicing, maintenance, repair, and disposal of stationary refrigeration and air conditioning equipment to prevent refrigerant venting.

What does the term 'ton of refrigeration' refer to?

Answer: 12,000 BTU/hr of cooling capacity

One ton of refrigeration equals 12,000 BTU/hr, originally based on the heat needed to melt one ton of ice in 24 hours.