NATE Air Conditioning 3

Question 1

Which type of compressor uses scroll technology and is common in modern residential AC units?

Accepted Answer

Scroll

Answer

Scroll compressors use two interlocking spirals and are favored in residential equipment for efficiency and quiet operation.

Question 2

What is the minimum SEER2 requirement for a new split-system AC unit installed in the US Southeast after January 1, 2023?

Accepted Answer

14 SEER2

Answer

The US Department of Energy set the minimum SEER2 efficiency standard at 14 for split systems in the Southeast and Southwest regions effective January 2023.

Question 3

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

Accepted Answer

Prevent refrigerant from migrating into the compressor oil during off cycles

Answer

Crankcase heaters keep compressor oil warm to prevent refrigerant absorption and potential liquid slugging on startup.

Question 4

When charging a system with R-410A, the refrigerant cylinder should be held in which orientation?

Accepted Answer

Upright for vapor, inverted for liquid

Answer

R-410A must be charged as a liquid (cylinder inverted through a valve) to maintain the correct blend ratio.

Question 5

What does a TXV (thermostatic expansion valve) use to control refrigerant flow?

Accepted Answer

Suction line superheat sensed by a bulb

Answer

A TXV senses evaporator outlet superheat via a sensing bulb and adjusts flow to maintain a set superheat.

NATE - North American Technician Excellence Practice Test

NATE - North American Technician Excellence Practice Test

NATE Air Conditioning 3