NATE Exam: Air Conditioning and Heat Pumps

NATE Exam: Air Conditioning and Heat Pumps

Questions with Complete Solutions Which of the following factors affects a customer's level of comfort?

• Air movement
• Humidity
• Temperature
• All of the above - Correct Answer d (All of the above: air movement, humidity, temperature)

A cooling load calculation estimates the sensible heat gain of a structure. The maximum sensible capacity of a cooling-only system should be within ____% of this calculated value.

• ±10%
• +10%
• +15%
• +30% - Correct Answer c (+15%)

The maximum sensible cooling capacity of a heat pump should be within ____% of the calculated sensible heat gain of a structure with a large heating load.

• ±10%
• +15%
• -25%
• +25% - Correct Answer d (+25%)

The combined output of a heat pump and its auxiliary heat should not exceed the calculated heat loss of a home by more than ____%.

• 10%
• 15% 1 / 3

• 20%
• 25% - Correct Answer b (15%)

What amount of auxiliary electric heat is needed when the output of a heat pump on a design day equals 18,800 Btuh and the heat loss of a home is 29,700 Btuh?

• 2.1 kWh
• 3.2 kWh
• 5.0 kWh
• 10.9 kWh

Note: 3,413 Btu/kW - Correct Answer b (3.2 kWh)

The three processes that transfer heat energy are conduction, convection, and ____.

• concentration
• radiation
• refraction
• static pressure - Correct Answer b (radiation)

Heat transfer that occurs when substances of different temperatures are in contact with each other is called ____.

• concentration
• conduction
• convection
• radiation - Correct Answer b (conduction)

What effect does raising the pressure in a sealed system have on refrigerant? 2 / 3

• It becomes more difficult to subcool the liquid refrigerant
• It becomes more difficult to superheat the refrigerant vapor
• The refrigerant's boiling point decreases
• The refrigerant's boiling point increases - Correct Answer d (The refrigerant's boiling point increases)

What is the primary danger to people near an accidental refrigerant release or spill?

• Blurred vision caused by the refrigerant vapor coming in contact with the eyes
• Changes in weather patterns caused by global warming
• Damage to the food chain caused by decreased ozone levels in the stratosphere
• Suffocation caused by the heavier refrigerant displacing oxygen in the air - Correct Answer d

(Suffocation caused by the heavier refrigerant displacing oxygen in the air) The maximum temperature at which refrigerant may be stored is ____°F when the container is no more than ____% full of liquid by volume.

• 120°F, 60%
• 125°F, 60%
• 125°F, 80%
• 135°F, 80% - Correct Answer c (125°F, 80%)

Boiling of the refrigerant occurs in which system component?

• Compressor
• Condenser
• Evaporator
• Metering device - Correct Answer c (Evaporator)
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