AIR DISTRIBUTION TEST QUESTIONS AND ANSWERS
A technician has determined a supply in a flexible duct system is leaking. Which of the
following should be checked? - Answers- All connections inner and outer layers.
There are two generally used methods for controlling temperature and humidity within
individual zones of a residence. One is use dampers to control supply airflow to each
zone. What is the other method? - Answers- One is to use dampers to control supply
airflow to each zone. The other is to use separate and independent systems to condition
the air in each zone.
A technician has determined a supply in a flexible duct system has been pulled loose.
How would this be repaired? - Answers- Using approved sealant an clamp
What are the preferred locations for the temperature probe when measuring
temperature rise across a heat exchanger in a gas furnace? - Answers- Read inlet
temperature in the return plenum as close as possible to the heat exchanger. Read
outlet temperature in the supply plenum as close as possible to the heat exchanger
How will the amperage reading of a PSC blower motor be affected by leaving the blower
access panel off during the measurement? - Answers- The amperage reading will be
higher with the door off.
The preferred method for closing the seam on a 4" section of rectangular duct board is
to: - Answers- Folding over flap, stapling and sealing with tape
The secondary condensate drains of an attic mounted horizontal air handler used with a
heat pump must always be connected: - Answers- In a location where occupants can
see water draining
An additional room is added to and existing home. A determination is made that the
system has enough capacity to meet the load requirements of the new space. On
insulation, an 8" supply duct is run to the room instead of the calculated 6" duct. What
will be the likely result of this error? - Answers- Lose more heat during in the winter
heating season and gain more heat in the summer cooling season.
Floor diffusers should be installed in boots or register boxes using: - Answers- No
mechanical fasterners
What is the effect of air velocity through a diffuser on duct system noise? - Answers-
Create turbulence and friction
Superheat in gas is defined: - Answers- sensible heat that is added to a vapor
The setting on a 4 speed PSC blower motor can be changed by changing the: -
Answers- Motor tap connection
, A wet bulb reading that is very close to the dry bulb reading from the same instrument
indicates the: - Answers- An oversized cooling system
How should a thermostat be set to perform an air balancing check of a cooling system?
- Answers- Turn the thermostat to bring on the selected blower speed when
The depth cut of an edging tool on a 1" thick section of duct board should be: -
Answers- ½ inch
How does an exhaust fan affect the air distribution in a commercial kitchen? - Answers-
How does an exhaust fan affect the air distribution in a commercial kitchen?
How would a technician check a three-phase blower motor to determine that it is
rotating in the proper direction? - Answers- By using the disconnect box to see how the
blower motor will be rotating.
To minimize noise problems in residential duct systems, what is the range of design air
velocity in the rectangular main supply trunk? - Answers- 700 to 900 Fpm
Which of the following is an important reason for using electronic defrost controls? -
Answers- They provide more accurate controls
What will an external static pressure check with a high reading indicate about the
performance of the blower? - Answers- The blower is developing enough RPM
The following condition exists. 1)residence built with slab construction 2) cold weather
climate 3) closet installed counterflow furnace - Answers- Perimeter loop duct
arrangement
Which of the following readings are most appropriate for a complete balance report? -
Answers- Total pressure, static pressure and outlet pressure
Which of the following is a preferred method for hanging rectangular duct board? -
Answers- Laid on 2" to 3" rigid metal chanel with hanger strap or rod.
Which is the set of measurements is required to calculate the cfm of an electric
furnace? - Answers- Supply air temp, return air temp voltage and amperage.
The leakage of air into a condition space is referred to as. - Answers- Infiltration
Which of the following is true of the efficiency media filters? - Answers- as media filter
efficiency increases the particulate size decreases and the pressure drop increases
A technician has determined a supply in a flexible duct system is leaking. Which of the
following should be checked? - Answers- All connections inner and outer layers.
There are two generally used methods for controlling temperature and humidity within
individual zones of a residence. One is use dampers to control supply airflow to each
zone. What is the other method? - Answers- One is to use dampers to control supply
airflow to each zone. The other is to use separate and independent systems to condition
the air in each zone.
A technician has determined a supply in a flexible duct system has been pulled loose.
How would this be repaired? - Answers- Using approved sealant an clamp
What are the preferred locations for the temperature probe when measuring
temperature rise across a heat exchanger in a gas furnace? - Answers- Read inlet
temperature in the return plenum as close as possible to the heat exchanger. Read
outlet temperature in the supply plenum as close as possible to the heat exchanger
How will the amperage reading of a PSC blower motor be affected by leaving the blower
access panel off during the measurement? - Answers- The amperage reading will be
higher with the door off.
The preferred method for closing the seam on a 4" section of rectangular duct board is
to: - Answers- Folding over flap, stapling and sealing with tape
The secondary condensate drains of an attic mounted horizontal air handler used with a
heat pump must always be connected: - Answers- In a location where occupants can
see water draining
An additional room is added to and existing home. A determination is made that the
system has enough capacity to meet the load requirements of the new space. On
insulation, an 8" supply duct is run to the room instead of the calculated 6" duct. What
will be the likely result of this error? - Answers- Lose more heat during in the winter
heating season and gain more heat in the summer cooling season.
Floor diffusers should be installed in boots or register boxes using: - Answers- No
mechanical fasterners
What is the effect of air velocity through a diffuser on duct system noise? - Answers-
Create turbulence and friction
Superheat in gas is defined: - Answers- sensible heat that is added to a vapor
The setting on a 4 speed PSC blower motor can be changed by changing the: -
Answers- Motor tap connection
, A wet bulb reading that is very close to the dry bulb reading from the same instrument
indicates the: - Answers- An oversized cooling system
How should a thermostat be set to perform an air balancing check of a cooling system?
- Answers- Turn the thermostat to bring on the selected blower speed when
The depth cut of an edging tool on a 1" thick section of duct board should be: -
Answers- ½ inch
How does an exhaust fan affect the air distribution in a commercial kitchen? - Answers-
How does an exhaust fan affect the air distribution in a commercial kitchen?
How would a technician check a three-phase blower motor to determine that it is
rotating in the proper direction? - Answers- By using the disconnect box to see how the
blower motor will be rotating.
To minimize noise problems in residential duct systems, what is the range of design air
velocity in the rectangular main supply trunk? - Answers- 700 to 900 Fpm
Which of the following is an important reason for using electronic defrost controls? -
Answers- They provide more accurate controls
What will an external static pressure check with a high reading indicate about the
performance of the blower? - Answers- The blower is developing enough RPM
The following condition exists. 1)residence built with slab construction 2) cold weather
climate 3) closet installed counterflow furnace - Answers- Perimeter loop duct
arrangement
Which of the following readings are most appropriate for a complete balance report? -
Answers- Total pressure, static pressure and outlet pressure
Which of the following is a preferred method for hanging rectangular duct board? -
Answers- Laid on 2" to 3" rigid metal chanel with hanger strap or rod.
Which is the set of measurements is required to calculate the cfm of an electric
furnace? - Answers- Supply air temp, return air temp voltage and amperage.
The leakage of air into a condition space is referred to as. - Answers- Infiltration
Which of the following is true of the efficiency media filters? - Answers- as media filter
efficiency increases the particulate size decreases and the pressure drop increases
