NATE Gas Heating Exam/ 50 Questions &
Answers.
Since 1992, the United States Department of Energy has required that all furnaces sold and installed
from that date on must have an AFUE of no less than:
A: 70%
B: 75%
C: 78%
,D: 80% - answer :C: 78%
Modern high-efficiency burners use combustion blowers. What are the two major types of combustion
blowers?
A: Induced draft and forced draft
B: High pressure and low pressure
C: Impeller type and centrifugal type
D: Liquid and vapor types - answer :A: Induced draft and forced draft
The purpose of the combustion blower is to:
A: Cause an adequate amount of oxygen-rich air to mix with the fuel for better combustion
B: Push the products of combustion out of the building
C: Prevent carbon monoxide from entering the heat exchanger
D: Give the larger blower motor a rest - answer :A: Cause an adequate amount of oxygen-rich air to mix
with the fuel for better combustion
Heat transfers from an object or area at a higher temperature to an object or area at a lower
temperature. A heated heat exchanger transfers heat to the air by:
A: Conduction
B: Natural convection
,C: Radiation
D: Forced convection - answer :D: Forced convection
The voltage that creates a spark on a spark ignition system is approximately:
A: 240 volts
B: 5,000 volts
C: 15,000 volts
D: 25,000 volts - answer :C: 15,000 volts
The capacity of a natural gas furnace is de-rated by _______ for every 1000 feet above sea level:
A: 1%
B: 2%
C: 3%
D: 4% - answer :D: 4%
A crack in a heat exchanger can:
A: Allow combustion gases to mix with the space air
, B: Prevent the heat from effectively transferring to the air
C: Cause the high-limit control to shut the furnace down
D: Cause the furnace to catch on fire - answer :A: Allow combustion gases to mix with the space air
Gas valves operate on what voltage?
A: 12 volts
B: 24 volts
C: 120 volts
D: 230 volts - answer :B: 24 volts
Mid-efficiency furnaces operate with flue gas temperatures between:
A: 275 and 360 degrees
B: 200 and 500 degrees
C: 100 and 275 degrees
D: 80 and 100 degrees - answer :A: 275 and 360 degrees
High-efficiency furnaces operate with flue gas temperatures between:
A: 275 and 360 degrees
Answers.
Since 1992, the United States Department of Energy has required that all furnaces sold and installed
from that date on must have an AFUE of no less than:
A: 70%
B: 75%
C: 78%
,D: 80% - answer :C: 78%
Modern high-efficiency burners use combustion blowers. What are the two major types of combustion
blowers?
A: Induced draft and forced draft
B: High pressure and low pressure
C: Impeller type and centrifugal type
D: Liquid and vapor types - answer :A: Induced draft and forced draft
The purpose of the combustion blower is to:
A: Cause an adequate amount of oxygen-rich air to mix with the fuel for better combustion
B: Push the products of combustion out of the building
C: Prevent carbon monoxide from entering the heat exchanger
D: Give the larger blower motor a rest - answer :A: Cause an adequate amount of oxygen-rich air to mix
with the fuel for better combustion
Heat transfers from an object or area at a higher temperature to an object or area at a lower
temperature. A heated heat exchanger transfers heat to the air by:
A: Conduction
B: Natural convection
,C: Radiation
D: Forced convection - answer :D: Forced convection
The voltage that creates a spark on a spark ignition system is approximately:
A: 240 volts
B: 5,000 volts
C: 15,000 volts
D: 25,000 volts - answer :C: 15,000 volts
The capacity of a natural gas furnace is de-rated by _______ for every 1000 feet above sea level:
A: 1%
B: 2%
C: 3%
D: 4% - answer :D: 4%
A crack in a heat exchanger can:
A: Allow combustion gases to mix with the space air
, B: Prevent the heat from effectively transferring to the air
C: Cause the high-limit control to shut the furnace down
D: Cause the furnace to catch on fire - answer :A: Allow combustion gases to mix with the space air
Gas valves operate on what voltage?
A: 12 volts
B: 24 volts
C: 120 volts
D: 230 volts - answer :B: 24 volts
Mid-efficiency furnaces operate with flue gas temperatures between:
A: 275 and 360 degrees
B: 200 and 500 degrees
C: 100 and 275 degrees
D: 80 and 100 degrees - answer :A: 275 and 360 degrees
High-efficiency furnaces operate with flue gas temperatures between:
A: 275 and 360 degrees
