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NOCTI HVAC STUDY GUIDE QUESTIONS WITH COMPLETE SOLUTIONS
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"After brazing a joint in a very tight location, the technician would use a(n) __________ to
determine if the joint is properly brazed. - CORRECT ANSWER Inspection mirror"
"refrigation can be dedcribed as - CORRECT ANSWER The process of removing heat from a
place where it makes little or no differenace"
"two locations where a cold air return should be installed - CORRECT ANSWER heat moves
towards a place with lower intensity"
"all refrigerant lines that are installed horizontally should - CORRECT ANSWER pitched
towards the compressor"
"when working with sharp or rough metal, the sheets metal worker should - CORRECT
ANSWER wear gloves and thick glasses"
"rubber soled, steel toes work boots help prevent injuries involving - CORRECT ANSWER
falling objects, and electric shock"
"the three components required for combustion are - CORRECT ANSWER fuel, Oxygen, and
heat"
"a pressure reading of 10in W.C is approximately equal to - CORRECT ANSWER 0.36 psig"
"Which power tool is best to cut steel rod? - CORRECT ANSWER Sawzall"
"CSST (steal tubing) connections - CORRECT ANSWER can be used with both natural and
propane gas equipment" "The type of pipe commonly used for condensation drainage on central air conditioning system is
- CORRECT ANSWER PVC"
"When pressure testing completed copper tubing assembly with pressuried nitrogen the nitrogen
cylinder should - CORRECT ANSWER always be on the ground"
"connections should be permanently connected with_____ on drainage piping assemblies that
uses PVC piping - CORRECT ANSWER Glue specified for PVC pipe"
"Using oxygen to purge copper tubing after brasing - CORRECT ANSWER could cause and
explosion"
"Two gases that considered non-condensable in a refrigeration - CORRECT ANSWER Air and
Nitrogen" "Residential air condition system have a super heat range of ____ degress under normal
operating conditions? - CORRECT ANSWER 8 to 12"
"which is not a condition of low superheat on an air conditioning system - CORRECT ANSWER
Refrigerant undercharged"
"The reason that subcooling would be below 8 degrees on air conditiong system - CORRECT
ANSWER dirty or blocked condenser coil"
"The cause for exessive subcoolinf in an air conditoning system? - CORRECT ANSWER system
operating in low abient conditions" "when reading blue prints for proper wall and duct location, the technician should look at the
______ - CORRECT ANSWER Floor plan"
"a 14-gauge soild copper wire would require____amp circuit protection - CORRECT ANSWER
15 amps"
"in a 24V circuit containing a switch and coil, it will read 24V at the coil if the - CORRECT
ANSWER switched is closed"
"A theremocouple produces _______ when heat is applied - CORRECT ANSWER DC voltage"
"in 120VC AC circuit, if the total circuit draws 5 amps the wattage is - CORRECT ANSWER 600"
"Capacitors are rated in - CORRECT ANSWER Volts and micro farads"
"The refrigerant enter the condenser as a - CORRECT ANSWER High pressure vapor"
"which type of oil is used in modern automotive air conditioning system? - CORRECT ANSWER
Glycols" "what year did it become necessary for all hvac technitions to become certified to handle
refrigerant under section 608 for thr clean air act? - CORRECT ANSWER 1994"
"which is not a health risk associted with the ozone depleation - CORRECT ANSWER lung
cancer"
"which refrgrant type of experiance the largest temperature glides? - CORRECT ANSWER
Zoetrope's" "The process od the removing refrigerant from an air conditioning system and storing it in an
external container? - CORRECT ANSWER Recovery"
"One-ton Ac system is? - CORRECT ANSWER 12,000 BTU's"
"One tone of AC requires how many CFMs - CORRECT ANSWER 400"
"Opposition to the flow of an alernating consumpton in A/c circuit - CORRECT ANSWER
Power=1 X E X power factor"
"R-22 i color coded - CORRECT ANSWER light green"
"the study of air and is properties is called - CORRECT ANSWER Psychometrics"
"the fitting used in duct work are? - CORRECT ANSWER plenum, extended plenum, Rducing
plenum or perimeter loop"
"Two types of non- conducting ladders - CORRECT ANSWER wood and fiberglass"
"how far should ladder stick out above a landing surface - CORRECT ANSWER 3 feet"
"The easiest way to move equipment across a roof is to use - CORRECT ANSWER plywood and
rollers"
"power tools that are not double insulted must have three prong plugs to ensure that the tool is
properly - CORRECT ANSWER grounded"
"the tool used to create internal threads is called a - CORRECT ANSWER tap"
"the tool to creat pipe threads on the outside of a pipe is called a - CORRECT ANSWER die"
"Fires that involve ordinary materials such as paper, cardboard, and wood are classified as Type
__________ fires. - CORRECT ANSWER A fires"
"In the electrical circuits, the _____ wire protects the operator - CORRECT ANSWER
Grounding"
"Fires that involve electrical equipment are classified as Type _____ fires. - CORRECT ANSWER
Type c fires" "electrical power should always be shut off at the ____ or entrance panel and locked in an
approved manner when installing equipment - CORRECT ANSWER distribuation"
"a ________ is used to measure the amount of CO2 in the flue product - CORRECT ANSWER
CO2/O2 indicator"
"the dial-type meter used to measure the pressure in a heating unit flue pipe is called a -
CORRECT ANSWER cordless drill"
"The ______ is referred to as kinetic displacement compresser - CORRECT ANSWER
centrifugal compresser" "The refrigerant vapor picks up additional heat as it flows from the evaporator to the compressor.
The heat is picked up from the _____. - CORRECT ANSWER suction line"
"what the purpose of the metering device? - CORRECT ANSWER Meters the flow of
refrigerant entering the evaporstor, reduced the boiler point to create a pressure/ temperature drop"
"Rejects both sensible and latent heat from the refrigeration system. - CORRECT ANSWER
condenser"
"vaporaztion can be increased by _____ the pressure on a liquid - CORRECT ANSWER
reducing"
"Every mechanical refrigeration system has __________ different pressure levels. - CORRECT
ANSWER 2"
"Pressure on the high pressure side of a mechanical refrigeration unit is called _______________.
- CORRECT ANSWER discharge or head pressure" "the exertion of pressure on a substance with a contant temperature increases it volume in
proportion to the increase in pressure - CORRECT ANSWER False"
"a 50/50 solder is a combination of lead and - CORRECT ANSWER tin"
"when calculating heat loss, the HTM means the - CORRECT ANSWER heating transfer
multiplier"
"The refrigerant used in smaller centrifugal compressors is - CORRECT ANSWER R-11"
"when writing a resume, its best to - CORRECT ANSWER accurately list education and work
history"
"of the following_______ sliver has the highest melting point - CORRECT ANSWER 65%"
"what is the angle of the- are shoulder? - CORRECT ANSWER 30 degrees"
"at standard conditions on the celsius scale water will boil at - CORRECT ANSWER 100 degrees
C"
"heat flows from warmer substanstance to a cooler substance - CORRECT ANSWER true"
"a bourdon tube is often found in a - CORRECT ANSWER pressure gauge"
"The PSIA at sea level under standard conditions is _____ psi. - CORRECT ANSWER 14.696"
"a metric term for pressure is - CORRECT ANSWER kilopascal"
"200 degress F converted to celcies equals - CORRECT ANSWER 93.3"
"the cylinder color code for R-502 is - CORRECT ANSWER purple"
"Enthalpy describes - CORRECT ANSWER The amount of heat a substance contains from some
starting point"
"the cylinder color for R-22 is - CORRECT ANSWER green"
"Reciprocating Compressor have - CORRECT ANSWER A piston and a cylinder"
"R-22 is a refrigerant most commonly used in ___________ systems - CORRECT ANSWER
residential air conditioning"
"water on the floor of the work area can - CORRECT ANSWER increase the chance of slipping
and receiving and electric shock"
"The ignition method that uses an eletric spark to ignite the pilot is called the - CORRECT
ANSWER intermittent pilot"
"which of the following hydrocarbons make up the largest precentage of natural gas - CORRECT
ANSWER methane"
"flame retention oil burners - CORRECT ANSWER produce a flame that is 300-500 F hotter
than conventional burners" “An Hvac system that depends on the temperatures below the ground surface as an operation
factor is a .. - CORRECT ANSWER Geothermal heat pump"
"when putting out a fire involving oily rags use a ________ fire extinguisher? - CORRECT
ANSWER Class B"
"The best tool to open and close the stem access valve on a refrigeriation system is the_______ -
CORRECT ANSWER Refrigeration service wrench"
"evacuting a system is accomplishedwith an _____ and helps to remove air and non- conditioning
and refrgeration applications - CORRECT ANSWER screw compressor"
"the four major components of a vapor compression refrigeration system are the compressor,
condenser, evaporator and - CORRECT ANSWER Metering Device"
"From a performance standpoint, a substitute for R-12 is ______. - CORRECT ANSWER R-
134A"
"What btu of heat is required to raise 1 pound of steam 1 degree F above the temperature of 212
degrees F? - CORRECT ANSWER .5"
"a day-ton of refartion is the amount of the refrigeration produced by melting 1 ton of ice at
temperature of 32 degrees F in 24 hours? - CORRECT ANSWER true"
"When one rises into the atmosphere, the atmospheric pressure decreases by 1 psi for every A. 2,343 feet B. 3,343 feet C. 2,500 feet
D. 5,280 feet - CORRECT ANSWER 2,343 feet"
"when filling out the service invoice during a routine preventive maintance call, worker should
record the - CORRECT ANSWER volts and amps readings"
"the standard atmospheric conditions for wateer to boil at 212 degree are - CORRECT
ANSWER atmosphere pressure 14.696 psi temp 70- degree F"
"Only liquid refrigerant should enter the metering device - CORRECT ANSWER True"
"a fusible plug is made from - CORRECT ANSWER a metal alloy that will burn when
overheated"
"Oil must never be used around a ______ cylinder. - CORRECT ANSWER acetylene"
"the three states of matter are - CORRECT ANSWER solid, liquid, gas"
"a gas law that states the total pressure of a combined mixture is equal to the sum of the
individual pressures is - CORRECT ANSWER daltons law"
