ABSA 4b 702 Questions with Complete Solutions 100

ABSA 4b 702 Questions with Complete Solutions 100% Verified Correct Answers 2024/2025 Warm Air Heating System Equipment In a warm air heating system the cold air return registers are located

• in exterior walls
• in interior locations
• under windows
• in floors
• in ceilings - Correct Answer B

The major disadvantage of an electric resistance coil furnace for warm air heating is

• the high cost of electricity
• the danger from electric shock
• the high cost of maintenance
• the large size of the furnace
• the location of electrical wiring - Correct Answer A

Lowboy furnaces are just over

• 1.0 m in height
• 0.8 m in height
• 1.4 m in height
• 1.6 m in height
• 1.2 m in height - Correct Answer E

The advantage of having duct furnaces instead of a large central furnace is 1 / 4

• less initial cost
• easier installation
• better control of heat in each zone of the building
• that they require less space
• lower maintenance costs - Correct Answer C

The power supply for an electric resistance coil furnace is

• 60 V
• 120 V
• 240 V
• 220 V
• 480 V - Correct Answer C

In a fin-coil heat exchanger the primary source of heat for the exchanger is

• steam or hot water
• gas
• oil
• solar
• radiant - Correct Answer A

A type of directly fired space heater is

• a unit heater
• a floor furnace
• a wall furnace
• all of the above
• none of the above - Correct Answer D

High efficiency furnaces and heaters range in annual fuel 2 / 4

utilization efficiency (AFUE) from

• 94 - 98%
• 80 - 95%
• 70 - 75%
• 60 - 70%
• 50 - 60% - Correct Answer B

In high efficiency furnaces if the temperature of the flue gas drops below 65 degrees C the

• flue gas will condense
• water vapour will condense
• furnace burner will shut down
• furnace burner will start up
• furnace vent will close - Correct Answer B

In a pulse combination furnace the stated efficiency is

• 94 - 98%
• 80 - 95%
• 70 - 75%
• 60 - 70%
• 50 - 60%

Warm Air Furnace Components and Maintenance - Correct Answer A Heat exchangers in gas fired furnaces are made of

• brass
• copper
• aluminum
• steel
• cast iron - Correct Answer D 3 / 4

Air filters can be divided into two groups

• mechanical and rotating drum
• electronic and steam
• dry and wet
• steam and rotating drum
• mechanical and electronic - Correct Answer E

Electronic filters will remove

• all particles from the air
• fine particles from the air
• odour producing gases from the air
• smoke from the air
• all of the above - Correct Answer B

The perimeter loop system of furnace ducting is ideal for a building with

• no insulation in the walls
• concrete walls
• no basement
• low head room in the basement
• no cold air returns - Correct Answer C

Which of the following is a type of outlet in a warm air heating system?

• a grill
• a register
• a ceiling diffuser
• a perforated panel
• / 4