WorksheetsFinal Review
Total questions: 71
Worksheet time: 36mins
What is required for electrons to move in a useful way?
Strong currents
Heat of compression
A resistor
A difference in charges
What does this symbol represent?
A close on fall thermal switch
A compressor overload
A motor
A close on rise pressure switch
Is a motor an inductive or a resistive load?
Inductive
Resistive
Neither
This is a trick question
This is the symbol for:
An air core transformer
An iron core transformer
A hard core contactor
A motor
A basic mercury bulb thermostat is a:
Load
Switch
Capacitor
Sign of the times
If you have a small 16-gauge extension cord and a larger 12-gauge extension cord, the best way to connect them is:
Connect the 12-gauge to the plug and then the 16-gauge
Connect the 16-gauge to the plug and then the 12-gauge
It makes no difference
What is a BTU a measure of?
Heat
Temperature
Water
Ice
At what temperature does water boil?
100 Kelvins
32 degrees Celsius
100 degrees Celsius
211 degrees Fahrenheit
The heat the earth receives from the Sun is an example of:
Radiation
Convection
Conduction
Sunburn
If a gas is cooled in a sealed container, it will:
Increase in volume
Become a liquid
Decrease in pressure
Increase in pressure
A refrigeration circuit…
Moves refrigerant by making it cold and increasing the velocity of the molecules
Pumps Freon into the evaporator coil, where it condenses into cold Freon particles
Manipulates the gas into latent heat, which makes the coils cold
Rejects heat by increasing the pressure and temperature, and it absorbs heat by decreasing the same
Blowing air into a space is an example of:
Refrigeration
Boyle's law
Convection
Radiation
How many BTUs make up a ton?
1,200 BTUs
12,000 BTU per day
280,000 BTUs per day
12,000 BTUs per minute
Decreasing pressure will result in a _________ boiling temperature.
Lower
Higher
Evaporation
Freon
Through which material does heat transfer at a greater rate?
A material that is a good conductor
A material that is considered a bad insulator, but good conductor
A material that is categorized as a good insulator
A material that is both a good conductor and a good insulator
If your furnace fails on a cold day, which of the following best describes what will happen?
The heat inside will migrate to the outside
Nothing will happen if the walls have enough insulation
The cold outside will migrate to the inside
Which of the following describes a heat pump system?
A small unit placed in a window
An indoor only gas powered unit
A ductless system with an outdoor unit and indoor wall mounted unit
An outdoor unit with a reversing valve and an indoor air handler
What connects the outdoor heat pump unit to the indoor air handler?
Potable water pipes
Ductwork
Line sets
Iron pipes
What is the minimum efficiency of a modern gas furnace?
80%
100%
40%
50%
When an electric furnace is part of a heat pump system, what can it do during the heat pump defrost process?
Provide electric to the heat pump
Provide electric heat to keep the conditioned space warm
Keep the line sets from freezing
Defrost the heat pump
Which of the following is a true statement about electric furnaces?
Electric furnaces contain multiple banks of electric heaters.
Electric furnaces can work alone in warm climates.
Electric furnaces can work as part of a heat pump system.
All of these
In electronic thermostats, which color wire provides 24 volts of power from the transformer to the corresponding terminal?
Yellow
White
Red
Green
What is the name of an electrical resistor used in an electronic thermostat to sense temperature?
Thermistors
Fossil fuel backup
Common wire
Low ambient control
Which controls are used to maintain a minimum head pressure when outdoor temperatures drop in an AC system?
Bi-metal temperature controls
Low ambient controls
Fossil fuel backups
Electronic thermostats
Which control is used to activate second stage heat when the outdoor temperature drops and the HVAC system cannot meet capacity demands?
Electromechanical thermostats
PTC thermistors
Low ambient controls
Fossil fuel backups
Which of the following is NOT true about electromechanical thermostats?
They contain manual switches that determine the mode of operation
They contain a bi-metal coil that moves during temperature changes
They may contain a hazardous material called mercury
They are the most common thermostat used in homes today
Which control is used to shut down the furnace if the temperature setting is exceeded?
Vapor charged controls
Motor overloads
High limit controls
Disc-type high/low pressure controls
Which of the following is NOT true about fuses and fusible links?
They are designed to break electrical current when the electrical current is greater than designed limit
They are still able to be reset and reused after use
They are used in compressors, evaporator coils, motors and wiring configurations
They are specified by their action, amperage rating, voltage, and physical size
Which of the following controls will shut down a motor by opening and breaking power to the motor?
Vapor charged controls
Disc-type temperature controls
Motor overloads
Compressor controls
Which heat pump defrost system allows for the unit to go into defrost no matter the amount of frost on the coil?
Temperature initiated-temperature terminated
Temperature initiated-time terminated
Time initiated-time terminated or straight time
All answers are correct
A boiler is fuel burning apparatus or container used for________.
Heating oil
Heating refrigerant
heating water
heating air
A ________ pump moves water through the boiler system to be re-heated.
condensate
circulating
A condensing boiler is classified as a 90% + boiler.
True
False
An _______ tank gives the water in the boiler room to expand.
air tank
refrigerant
expansion
hot water
A ______ reducing valve reduces the water pressure from house pressure to boiler operating pressure.
water
pressure
heat
air
TPRs are designed to automatically release ________ in the event that pressure or temperature in the water tank exceeds safe levels.
air
refrigerant
heat
water
An _________ is an in-line device that removes entrained air (microbubbles) that is moving with the flow of the fluid.
circulating pump
air separator
pressure reducing valve
air line
A boiler uses a _________ device to give off heat created by the boiler.
radiator
register
vent
return air
The temperature surrounding an object is called what?
Radiant temperature
Air Temperature
Atmospheric Temperature
Ambient Temperature
What is the function of the "R" terminal on a low voltage thermostat?
To provide 24 volts from the transformer
To provide 24 to the transformer
To control the heating relay
To control the cooling relay
What is the function of the "W" terminal on the low voltage thermostat?
To provide 24 volts from the thermostat
To provide 24 volts to the heating relay
To provide 24 volts to the cooling relay
To provide 24 volts to the fan relay
What is the function of the "Y" terminal on the low voltage thermostat?
To provide 24 volts from the transformer
To provide 24 volts to the heating relay
To provide 24 volts to the cooling relay
To provide 24 volts to the fan relay
What is the function of the "G" terminal on the low voltage thermostat?
To provide 24 volts from the transfomer
To provide 24 volts to the heating relay
To provide 24 volts to the cooling relay
To provide 24 volts to the fan relay
What is the function of the "C" terminal on the low voltage thermostat?
To provide 24 volts from the transformer
To provide 24 volts to the heating relay
To provide 24 volts to the cooling relay
To provide a ground "common" to the thermostat to "hard wire" the thermostat.
Which answer is not a condition that affects static pressure?
Dirty Filter
Dirty Evaporator
Undersized duct work
Dirty Condenser
The liquid line connects the condenser outlet to the _______________________.
Metering device
Suction line
Evaporator inlet
all answers are correct
The suction line connects the evaporator outlet to the ________________________.
Compressor inlet
Compressor outlet
Condenser inlet
Condenser outlet
The metering device is connected to the _______________________.
Condenser inlet
Condenser outlet
Evaporator inlet
Evaporator outlet
AWG stands for.
All Weather Gaurd
American Wire Gauge
According to the AWG wiring system, the higher the number the ___________ the conductor size.
Smaller
Larger
When performing an air temperature rise test you should let the appliance run at least how long?
5-10 minutes
10-15 minutes
15-20 minutes
20-30 minutes
If you are too close to the low end of the temperature rise, the air coming off the furnace will feel _______________.
to hot
to cold
just right
uneven
If you are too close to the low end of the temperature rise you may start to form________________.
Condensation
Steam
Heat
nothing at all.
When we are near or over the high-end of the temperature rise the furnace may begin cycling on and off the ________________.
Thermostat
Inducer motor
Flame sensor
Limit
The outdoor coil on heat pump becomes the ___________ in heating mode.
Condenser
Evaporator
Metering Device
Blower Section
Why is it important to know what factors impact the heat load of a home?
to select the proper air duct materials and fittings
to select the appropriate HVAC equipment
to select and locate grilles, registers and diffusers
to select the appropriate building material for a home
Heat load is
the amount of heat a building needs to maintain the indoor temperature at the desired levels
the amount of sensible heat that must be removed by the air conditioning equipment in a building
the amount of heating and cooling the equipment can withhold in order to maintain the design temperature at the desired levels
the input BTU rating of the HVAC equipment
Which one of the following factors can impact both the heat gain and heat loss of a building?
electric appliances, the number of occupants, building materials and the level of insulation used.
the type of furniture used with the building
the orientation of windows and skylights
the coloring of appliances and the ductwork uded in the home
Which three categories include factors that need to be considered when calculating the heating and cooling load of a home?
climate, design conditions, and building details
building orientation, climate, and home occupants
insulation, building design, and appliances
outdoor relative humidity
A limit switch is an overtemperature device use to prevent overheating of an appliance such as a furnace. Limit switches are in the normally ___________ position.
open
over
closed
under
A rollout switch is ____________ resettable.
manually
automatically
openly
always
A fan switch is in the normally __________ position.
open
closed
over
under
An air temperature rise is the temperature difference between the return and heated ___________ air.
cold
warm
hot
supply
An electrical device that makes it possible to decrease voltage is called________?
Relay
Transformer
Switch
Thermostat
An ohmeter is an instrument for accurately checking__________?
Resistance
Voltage
Temperature
Amperarage
A condition involving an unintentional electrical path with very low or no resistance is called?
Open Circuit
Short Circuit
Closed Circuit
A limit switch can be tripped due to__________.
Dirty filter
Undersized Ductwork
Bad or Dirty Blower
All of the above
A safety device used to detect the presence of flame in a gas burning appliance is called ___________?
Hot surface igniter
Flame sensor
Limit switch
Pressure Switch
A compound gauge makes it possible to measure pressures ___________ and _____________ atmospheric pressure.
the same or = to
IN and Out
Hot and Cold
Above and below
A BTU is the amount of heat required to raise the temperature of 1 _______ of water by 1 degree Fahrenheit.
Gallon
Pound
Ounce
Pan
The temperature surrounding an object is known as the ___________ temperature.
Superheat
Subcooled
Object
Ambient
