HVAC Contractor Exam Test 7 With All Correct & 100%
Verified Answers |Latest Update| Already Graded A+
How much heat is required to melt a 10 pound block of ice that is sitting at 32 degrees F into warm
water given that the heating temperature is at 80 degrees F? ✔Correct Answer-1,920 Btu/h
In many condensing unit applications, it is necessary to heat the compressor to evaporate liquid
refrigerant trapped in the oil. Many large compressors for commercial applications are manufactured
and equipped to handle this situation using a _________? ✔Correct Answer-Crankcase heater
Find the MINIMUM size chimney required: A fan assisted Category 1 appliance with an input rating of
55,000 Btu/h is to be vented with a single wall connector into a masonry chimney that is 20 feet high
with a 10 foot lateral. ✔Correct Answer-It is not recommended that this appliance be connected
tot his chimney
Given that a motor compressor has a 2" bore and a 3" stroke, what would be the calculated piston
displacement in cubic inches? ✔Correct Answer-9.42
A grain is a unit of weight equal to ___________, used to indicate the amount of moisture in the air.
✔Correct Answer-1/7000 lb
When computing heat leakage for a building, the U-value for most types of construction can be
obtained from reference books. The unit of measure for U-value is expressed in __________?
✔Correct Answer-Btu/sq-ft/deg.F/Hr
Absolute zero temperature is the temperature at which all molecular motion ceases at approximately
_______degrees Fahrenheit. ✔Correct Answer--460 degrees F
What would be the calculated resistance of a circuits load, given that the load draws a total current
of 20 amperes, and the circuit source operating voltage is 240 VAC? ✔Correct Answer-12.0
A contractor is working with auxiliary drain pans in a secondary drain system for an air conditioning
system. How deep should these auxiliary drain pans be, AT LEAST? ✔Correct Answer-1-1/2 inches
The operation of the thermostatic expansion valve is controlled by the temperature of the thermal
expansion valve and the pressure in the evaporator. Therefore, when does the needle valve in the
refrigeration system normally open? ✔Correct Answer-When the evaporator pressure is low and
the temperature is above normal
According to International fire code Fire Code, duct smoke detectors in heating and AC systems must
be connected to what? ✔Correct Answer-The building fire alarm system
Voltmeters are always connected in __________ with the circuit when measuring for proper voltage
✔Correct Answer-Parallel
What is the term for a condition where a substance changes from a solid to a gas vapor without
becoming a liquid? ✔Correct Answer-Sublimation
, The MINIMUM cross-sectional dimension of a combustion air duct is __________ inches
✔Correct Answer-3 inches
Identify the INCORRECT method for joints in plastic fuel gas piping: ✔Correct Answer-Threaded
Good practice demands that when a tube constrictor is used to prep a brazed joint, the tubes should
be as close as____________ to each other. ✔Correct Answer-.003"
Geothermal heat pumps are considered the most efficient conditioning systems available. These
pumps can reduce energy consumption and emissions by over__________ compared to air source
heat pump's. ✔Correct Answer-40%
Exhaust outlets shall be located NOT LESS than_________ feet horizontally from above the air intake
openings into any building. Example: a commercial cooking exhaust outlets and air intakes.
✔Correct Answer-10 feet
Return air openings for heating, ventilation and air-conditioning systems shall not be taken from a
closet, bathroom, toilet room, kitchen, garage, boiler room, furnace room or unconditioned attic,
however, a__________ is not prohibited ✔Correct Answer-Bedroom
The__________ Compressor uses a disk with radio impellers that spin rapidly to compress refrigerant
✔Correct Answer-Centrifugal
Enthakpy is the measure of the heat content of a substance, determined by both the temperature in
the pressure of the substance. The correct formula for enthalpy is: ✔Correct Answer-H=M x sp.ht.
x delta T
One of the most popular types of the hermetically sealed compressors or the reciprocating
compressors, the systems typically use what type of motor? ✔Correct Answer-Capacitor-start,
induction-run
There are five principal types of refrigerant flow controls, of the following types listed below, which
one is NOT a main type of automatic refrigerant flow control? ✔Correct Answer-Condenser
Equalizer Valve
Conduction is the flow of heat between parts of a substance by molecular vibrations. Heat causes
solids to become liquid or gases, and conduction travels from ✔Correct Answer-Warmer to colder
objects
Identify the most commonly expansion device used on multiple-evaporator systems to provide
different temperatures in various cabinets on air conditioning systems. ✔Correct Answer-
Thermostatic expansion valve
Most cooper tubing used in air conditioning and refrigeration work is known as ACR tubing, available
in soft and hard types. According to the Modern Refrigeration and Air-Conditioning textbook, what is
the most common type of ACR copper tubing used in industry today? ✔Correct Answer-Type L
Select a number of psi, without going over the limit, an acetylene manifold pressure must be at
✔Correct Answer-15 psi
Verified Answers |Latest Update| Already Graded A+
How much heat is required to melt a 10 pound block of ice that is sitting at 32 degrees F into warm
water given that the heating temperature is at 80 degrees F? ✔Correct Answer-1,920 Btu/h
In many condensing unit applications, it is necessary to heat the compressor to evaporate liquid
refrigerant trapped in the oil. Many large compressors for commercial applications are manufactured
and equipped to handle this situation using a _________? ✔Correct Answer-Crankcase heater
Find the MINIMUM size chimney required: A fan assisted Category 1 appliance with an input rating of
55,000 Btu/h is to be vented with a single wall connector into a masonry chimney that is 20 feet high
with a 10 foot lateral. ✔Correct Answer-It is not recommended that this appliance be connected
tot his chimney
Given that a motor compressor has a 2" bore and a 3" stroke, what would be the calculated piston
displacement in cubic inches? ✔Correct Answer-9.42
A grain is a unit of weight equal to ___________, used to indicate the amount of moisture in the air.
✔Correct Answer-1/7000 lb
When computing heat leakage for a building, the U-value for most types of construction can be
obtained from reference books. The unit of measure for U-value is expressed in __________?
✔Correct Answer-Btu/sq-ft/deg.F/Hr
Absolute zero temperature is the temperature at which all molecular motion ceases at approximately
_______degrees Fahrenheit. ✔Correct Answer--460 degrees F
What would be the calculated resistance of a circuits load, given that the load draws a total current
of 20 amperes, and the circuit source operating voltage is 240 VAC? ✔Correct Answer-12.0
A contractor is working with auxiliary drain pans in a secondary drain system for an air conditioning
system. How deep should these auxiliary drain pans be, AT LEAST? ✔Correct Answer-1-1/2 inches
The operation of the thermostatic expansion valve is controlled by the temperature of the thermal
expansion valve and the pressure in the evaporator. Therefore, when does the needle valve in the
refrigeration system normally open? ✔Correct Answer-When the evaporator pressure is low and
the temperature is above normal
According to International fire code Fire Code, duct smoke detectors in heating and AC systems must
be connected to what? ✔Correct Answer-The building fire alarm system
Voltmeters are always connected in __________ with the circuit when measuring for proper voltage
✔Correct Answer-Parallel
What is the term for a condition where a substance changes from a solid to a gas vapor without
becoming a liquid? ✔Correct Answer-Sublimation
, The MINIMUM cross-sectional dimension of a combustion air duct is __________ inches
✔Correct Answer-3 inches
Identify the INCORRECT method for joints in plastic fuel gas piping: ✔Correct Answer-Threaded
Good practice demands that when a tube constrictor is used to prep a brazed joint, the tubes should
be as close as____________ to each other. ✔Correct Answer-.003"
Geothermal heat pumps are considered the most efficient conditioning systems available. These
pumps can reduce energy consumption and emissions by over__________ compared to air source
heat pump's. ✔Correct Answer-40%
Exhaust outlets shall be located NOT LESS than_________ feet horizontally from above the air intake
openings into any building. Example: a commercial cooking exhaust outlets and air intakes.
✔Correct Answer-10 feet
Return air openings for heating, ventilation and air-conditioning systems shall not be taken from a
closet, bathroom, toilet room, kitchen, garage, boiler room, furnace room or unconditioned attic,
however, a__________ is not prohibited ✔Correct Answer-Bedroom
The__________ Compressor uses a disk with radio impellers that spin rapidly to compress refrigerant
✔Correct Answer-Centrifugal
Enthakpy is the measure of the heat content of a substance, determined by both the temperature in
the pressure of the substance. The correct formula for enthalpy is: ✔Correct Answer-H=M x sp.ht.
x delta T
One of the most popular types of the hermetically sealed compressors or the reciprocating
compressors, the systems typically use what type of motor? ✔Correct Answer-Capacitor-start,
induction-run
There are five principal types of refrigerant flow controls, of the following types listed below, which
one is NOT a main type of automatic refrigerant flow control? ✔Correct Answer-Condenser
Equalizer Valve
Conduction is the flow of heat between parts of a substance by molecular vibrations. Heat causes
solids to become liquid or gases, and conduction travels from ✔Correct Answer-Warmer to colder
objects
Identify the most commonly expansion device used on multiple-evaporator systems to provide
different temperatures in various cabinets on air conditioning systems. ✔Correct Answer-
Thermostatic expansion valve
Most cooper tubing used in air conditioning and refrigeration work is known as ACR tubing, available
in soft and hard types. According to the Modern Refrigeration and Air-Conditioning textbook, what is
the most common type of ACR copper tubing used in industry today? ✔Correct Answer-Type L
Select a number of psi, without going over the limit, an acetylene manifold pressure must be at
✔Correct Answer-15 psi
