Warm air heating systems

Question 1

Heat may be added to a building’s forced air system by means of:

A) Duct silencers
B) Fans
C) Fin-coil heat exchangers
D) Dampers
E) Electronic control

Answer 1

C) Fin-coil heat exchangers

Question 2

In high efficiency furnaces, if the temperature of the flue gas drops below 65°C, the:

A) Water vapor will condense
B) Furnace vent will close
C) Furnace burner will start up
D) Furnace burner will shut down
E) Flue gas will condense

Answer 2

A) Water vapor will condense

Question 3

One of the advantages forced warm air heating systems has over steam or hot water heating systems is the:

A) Ease of installation of the air duct
B) Systems are virtually noise free
C) Systems are maintenance free
D) Air can be humidified and filtered
E) Systems do not require electricity

Answer 3

D) Air can be humidified and filtered

Question 4

A pulse combination condensing furnace stated efficiency is:

A) 80 - 95%
B) 94 - 98%
C) 70 - 75%
D) 60 - 70%
E) 50 - 60%

Answer 4

B) 94 - 98%

Question 5

Various types of heat sources are used in warm air heating systems. They can be divided into the following classes:

1. Indirectly-fired
2. Directly fired
3. Electric resistance coil
4. High voltage coil
5. Fin-coil heat exchanger

A) 1, 2, 3
B) 3, 4, 5
C) 2, 3, 5
D) 1, 3, 4
E) 2, 3, 4

Answer 5

C) 2, 3, 5

Question 6

Three types of direct fired forced warm air furnaces are:

A) Zone, direct volume and variable volume
B) Steam unit ventilators, hot water unit ventilators, and finned hot water convection
C) Horizontal, upflow and downflow
D) Dual duct, terminal reheat, and constant volume
E) Hydronic, steam, and finned electric

Answer 6

C) Horizontal, upflow and downflow

Question 7

High efficiency warm air furnaces require:

A) Increased gas pressure
B) Large vent stacks
C) Larger fans
D) Condensate drains to waste
E) More air

Answer 7

D) Condensate drains to waste

Question 8

In a warm air heating system, the cold air return registers are located:

A) In floors
B) In ceilings
C) Under windows
D) In interior locations
E) In exterior walls

Answer 8

D) In interior locations

Question 9

An advantage of an electric resistance warm air furnace is:

A) Lower installation cost
B) More efficient
C) Elimination of burners and fuel
D) All of these are correct
E) More compact

Answer 9

D) All of these are correct