Residential Air Conditioning Final Review

C

Three common evaporator coil configurations found on air-conditioning systems are A. slant, A, and V B. A, V, and H C. slant, A, and H D. A, H, and V

A

Which of the EPA Section 608 certification is required to work on small appliances? A. Type 1 B. Type 2 C. Type 3 D. Type 4

A

Which of the following best describes the scrolls in a scroll compressor? A. One scroll is stationary and one scroll orbits B. Both scrolls are stationary C. Both scrolls orbit clockwise D. Both scrolls orbit couterclockwise

D

Which of the following classes of refrigerants is potentially dangerous because of its high flammability? A. HFO B. HCFC C. CFC D. HC

B

The term used to describe the range of boiling and condensing temperatures at a given pressure is called ___________________. A. saturation pressure B. temperature glide C. saturation temperature D. sublimation

B

The willful purging or venting of certain refrigerants to the atmosphere is A. essential to the preservation of the stratospheric ozone B. illegal as set forth by EPA regulations C. encouraged by the EPA as it helps to protect tropospheric ozone D. desirable as this process helps improve food preservation efforts

D

What refrigerant lines are field installed on the typical package-type-air-conditioning unit? A. Liquid line and suction line B. Discharge line and liquid line C. Discharge and suction line D. Package-type equipment has no field-installed refrigerant lines

B

When sizing and selecting air-conditioning equipment, which of the following must be taken into account? A. Dirt content B. Moisture content C. Smoke content D. Pollen content

B?

Which of the following best describes the air that enters the structure after being treated by an evaporative cooler? A. Warm and humid B. Warm and dry C. Cool and humid D. Cool and dry

C

Which of the following represents a complete list of the elements contained in CFC refrigerants? A. Hydrogen, chlorine, fluorine, and carbon B. Hydrogen, chlorine, and carbon C. Chlorine, fluorine, and carbon D. Hydrogen and carbon

B

Which of the following represents a complete list of the elements contained in HFC refrigerants? A. Hydrogen, chlorine, fluorine, and carbon B. Hydrogen, fluorine, and carbon C. Chlorine, fluorine, and carbon D. Hydrogen and carbon

B

A DOT-approved refrigerant recovery cylinder is color-coded A. with yellow and gray stripes B. gray with a yellow top C. yellow with a gray top D. yellow with gray triangles

A

A _________________ can be used to check the oil composition of a system after a retrofit has been done A. refractometer B. reclaimer C. sight glass D. acid test

B

A __________________ can remove any type of foreign matter that enters a refrigeration system A. vacuum pump B. filter drier C. recovery machine D. compressor

True

A common term for tropospheric ozone pollution is smog. True or False

D

A deep vacuum can most accurately be measured in A. inches of mercury B. inches of water column C. pounds per square inch D. microns

A

A large refrigeration system that contains a significant amount of moisture should be evacuated with A. a high CFM vacuum pump B. a low CFM vacuum pump C. the system compressor running D. a recovery machine then a nitrogen sweep

C

A system that is equipped with a ___________________ may require additional steps to ensure that the entire system is evacuated A. TXV B. Relief valve C. solenoid valve D. receiver

B

A typical multihead, ductless split system is configured with A. multiple outdoor units and one indoor unit B. multiple indoor units and one outdoor unit C. multiple outdoor units and multiple indoor units D. one indoor unit and one outdoor unit

False

All 500-series refrigerant blends have temperature glide and have potential to fractionate. True or False

C

All of the following are true regarding the scroll compressor except A. there are no valves in the scroll compressor B. the scrolls tend to "wear in" over time C. there is a clearance volume that traps some refrigerant D. they are more efficient than reciprocating compressors

D

All of the following tasks are part of a refrigerant retrofitting process except A. label the system with information about the new refrigerant and system charge B. adjust all refrigerant flow devices such as TXVs, CPRs, and EPRs, as needed C. obtain a complete set of baseline data for the system to retrofitting D. ensure that the evaporator fan motor is off during system charging

A

An evacuation process that is performed a number of times with nitrogen being used to break the vacuum, and ends with a deep vacuum is known as A. triple evacuation B. refrigerant recovery C. system flush D. nitrogen sweep

A

An increase in the natural greenhouse effect that leads to the heating of the earth is called A. global warming B. planetary effect C. planetary warming D. global effect

D

An oily dust spot on a condenser or evaporator coil could indicate A. a defective fan motor B. noncondensables in the system C. the presence of acid D. a refrigerant leak

B

As refrigerant undergoes the compression process A. the pressure of the refrigerant increases, while its temperature decreases B. the pressure and temperature of the refrigerant increase C. the pressure of the refrigerant decreases, while its temperature increases D. the pressure and temperature of the refrigerant decrease

D

At or near design conditions the supply and return temperatures for an air-conditioning system are closest to A. 75 degrees F supply air, 55 degrees F return air B. 70 degrees F supply air, 60 degrees F return air C. 60 degrees F supply air, 65 degrees F return air D. 55 degrees F supply air, 75 degrees F return air

B

CFCs are more harmful to the stratospheric ozone layer than HFCs because CFCs contain A. fluorine B. chlorine C. hydrogen D. carbon

A

Discharge gas temperature is affected most by A. the temperature of the suction gas B. the type of metering device used C. the type of condenser used D. the temperature of the refrigerant oil

A

Each degree of condenser subcooling will increase system efficiency by approximately how much? A. 1% B. 3% C. 5% D. 8%

B

Evaporative cooling systems are best suited for which type of climate? A. Hot, humid climate B. Hot, dry climate C. Cool, humid climate D. Cool, dry climate

C

HFC-based refrigerant blends perform best with a(n) _____________ lubricant. A. alkylbenzene B. polyalkylene gylcol (PAG) C. ester D. mineral

A

HFO refrigerants are classified as having A. low GWPs and low ODPs B. low GWPs and high ODPs C. high GWPs and low ODPs D. high GWPs and high ODPs

D

Heat leaks into a structure by which three methods A. Conduction, convection, and radiation B. Infiltration, convection, and radiation C. Conduction, convection, and radiation D. Conduction, infiltration, and radiation

C

How are oil-less compressors on recovery units lubricated? A. They still use oil, just less B. The compressor shaft floats so no lubrication is needed C. They rely on residual oil in the recovered refrigerant D. The compressor is magnetic, so no oil is required

D

If a duct system is uninsulated and runs through the conditioned space A. there will be a net duct loss while the system is operating in the cooling mode only B. there will be a net duct loss while the system is operating in the heating mode only C. there will be a net duct loss while the system is operating in both the cooling and heating mode D. there will be no net duct losses while the system is operating in either the cooling or heating mode

B

If a refrigerant experiences a temperature glide, which of the following can be correctly concluded? A. The refrigerant is a single-compound substance B. The refrigerant is a blended refrigerant C. The refrigerant is classified as an HCFC D. The refrigerant is classified as a CFC

D

In order to remove moisture from a refrigeration system using a vacuum pump, it must be in a ________________ state A. solid B. heated C. liquid D. vapor

C

It is estimated that a single chlorine atom can destroy up to ___________ ozone molecules? A. 1000 B. 10,000 C. 100,000 D. 1,000,000

D

Leaks that occur only when the unit is in operation are called A. combination-dependent leaks B. temperature-dependent leaks C. cumulative microleaks D. vibration-dependent leaks

C

Low-loss fittings are intended to ensure that A. no refrigerant is trapped in hoses when removed from system B. no nitrogen is trapped in hoses when removed from system C. refrigerant losses are minimized when removing hoses from system D. refrigerant losses are maximized when removing hoses from system

D

Moisture, acid buildup, and copper plating can be caused by which of the following? A. Refrigerant and oil mixing B. A clogged filter dryer C. An undersized evaporator D. Air in the system

B

Multicircuit evaporators are equipped with which of the following components? A. A refrigerant distributor located at the inlet of the metering device B. A refrigerant distributor located at the outlet of the metering device C. A refrigerant receiver located at the outlet of the metering device D. A refrigerant receiver located at the outlet of the evaporator coil

B

Of the following refrigerants, which is best suited as a retrofit refrigerant for an R-22 residential air-conditioning system? A. R-134a B. R-410A C. R-407C D. R-123

A?

On average, each tone of system capacity has the ability to remove approximately how much moisture from the air? A. One cup B. One pint C. One quart D. One gallon

A

One of the advantages of a microfoam leak detection solution over standard bubble solutions is that it A. will not pit or corrode the components B. contains chlorides C. can detect leaks as small as 0.1 oz per year D. will react with refrigerant oil and become luminescent

A

Ozone in the stratosphere protects the earth from ______________. A. UV-B radiation B. pollutants and smog C. meteorites D. excessive heat

A

Package-type air-conditioning units are intended to be located A. either on the roof of a structure or at ground level B. only on the roof of a structure C. only in the attic of a residence D. only at ground level

C

Proper evacuation without the use of a gauge manifold requires which of the following? A. Recovery machine B. Nitrogen and a pressure regulator C. Core removal tool D. Electronic leak detector

B

Proper maintenance for a vacuum pump would include which of the following? A. Replacing all of the caps and plugs with new ones B. Changing the oil as often as necessary C. Replacing the oil sight glass D. Installing a new motor on the pump

B

Radial sealing on a scroll compressor is typically accomplished with A. floating seals B. oil C. mechanical connections D. grease fittings

A

Reciprocating compressors used in residential applications are most likely to be A. fully hermetic, suction gas-cooled pumps B. semi hermetic, suction-gas-cooled pumps C. fully hermetic, discharge-gas-cooled pumps D. semi hermetic, discharge-gas-cooled pumps

D

Recovery that can capture the entire system charge and pump it into a tank is known as _____________. A. system-dependent recovery B. recycling C. passive recovery D. active recovery

A

Referring to Figure 36.18, the 1% design wet-bulb and dry-bulb temperature for Napa, California in the summer are A. 100 degrees F dry-bulb, 71 degrees F wet-bulb B. 100 degrees F dry-bulb, 69 degrees F wet-bulb C. 96 degrees F dry-bulb, 69 degrees F wet-bulb D. 96 degrees F dry-bulb, 67 degrees F wet-bulb

B

Refrigerant released while making good-faith attempts to recapture and recycle or safely dispose of refrigerant including releases that occur when connecting or disconnecting hoses is called _______________. A. EPA allowance B. de minimus C. tolerance D. venting

A

Refrigerants R-11, R-12, and R-22 all have what in common? A. They are all methane-based refrigerants B. They are all ethane-based refrigerants C. They are all CFC refrigerants D. They are all HCFC refrigerants

B

Standing, pressure-dependent, temperature-dependent, vibration-dependent, combination-dependent, and micro are all types of A. charging methods B. leak methods C. evacuation methods D. electronic micron gauges

B

The Montreal Protocol is best described as a A. set of laws that put an end to CFC and HCFC production B. treaty or agreement among nations to address ozone depletion C. law put in place by the EPA to override the Clean Air Act D. treaty between the EPA and the U.S government to stop venting

D

The _______________ is both the greatest asset and the greatest liability of an electronic leak detector A. range B. battery life C. cost D. sensitivity

C

The compressor type that relies on pistons moving up and down within cylinders is the A. stationary-vane rotary compressor B. rotary-vane rotary compressor C. reciprocating compressor D. scroll compressor

C

The condensing unit of a split-type air-conditioning system is made up of the A. metering device and evaporator coil B. compressor and metering device C. condenser coil and compressor D. evaporator and condenser coils

C

The low-pressure side of the system must not be pressurized to more than ___________ when testing for leaks. A. 75 psig B. 200 psig C. the low-side design pressure D. atmospheric pressure

D

The maximum desired discharge line temperature for an R-410A compressor is A. 100 degrees F B. 125 degrees F C. 150 degrees F D. 175 degrees F

D

The most accurate type of gauge for measuring a deep vacuum is a A. compound gauge B. digital manometer C. mercury manometer D. digital micron gauge

D

The most common type of refrigeration oil used in conjunction with HFC refrigerants is A. animal B. vegetable C. alkylbenzene D. esters

B

The numeric series used for zeotropic and near-azeotropic refrigerant blends are the ______________. A. 100's B. 400's C. 200's D. 300's

C

The only two substances that should be circulating in a refrigeration system are A. liquid and vapor B. refrigerant and nitrogen C. refrigerant and oil D. nitrogen and oil

C

The refrigerant that both enters and leaves a properly operating compressor can best be described as A. low-pressure vapor B. high-pressure vapor C. superheated vapor D. subcooled vapor

A

The safest overall rating with respect to both toxicity and flammability is A. A1 B. B1 C. A3 D. B3

B

The standard that a refrigerant must meet after it has been reclaimed is A. AHRI 7000 B. AHRI 700 C. AHRI 7400 D. AHRI 740

D

The standard that a refrigerant must meet after it has been recycling is A. AHRI 7000 B. AHRI 700 C. AHRI 7400 D. AHRI 740

D

The suction line is insulated to A. prevent the liquid refrigerant in the line from rejecting additional, unwanted heat B. prevent the liquid refrigerant in the line from absorbing additional, unwanted heat C. prevent the vapor refrigerant in the line from rejecting additional, unwanted heat D. prevent the vapor refrigerant in the line from absorbing additional, unwanted heat

False

The tare weight of a recovery tank is the weight of the tank if it were filled with water. True or False

A

The temperature of the evaporator is affected A. only by the amount of air passing through the coil B. only by the temperature of the air passing through the coil C. by both the temperature and amount of air passing through the coil D. by neither the temperature nor the amount of air passing through the coil

A

The term "fractionation" refers to the A. separation of a refrigerant blend into its component parts B. ability of refrigeration oil to lubricate effectively C. range of saturation temperatures at a given pressure D. effects of released refrigerants on part of the atmosphere

A

The term used to describe a recovery process that uses a self-contained recovery unit is A. active B. passive C. recycling D. recovering

C

The term used to describe the process of removing refrigerant from a system and filtering and/or cleaning it to meet AHRI 740 standards is A. restoring B. reclaiming C. recycling D. recovering

D

The term used to describe the process of removing refrigerant from a system and storing it without testing or processing it is A. restoring B. reclaiming C. recycling D. recovering

B

The term used to describe the process of removing refrigerant from a system and surrendering it for reprocessing to meet AHRI 700 standards is A. restoring B. reclaiming C. recycling D. recovering

A

What refrigerant lines are field installed on the typical split-type air-conditioning system? A. Liquid line and suction line B. Discharge line and liquid line C. Expansion line and discharge line D. Suction line and expansion line

C

What term is used to describe the certification that is awarded when a technician passes all the parts of an EPA certification exam? A. Global B. Stellar C. Universal D. Galactical

B

When a deep vacuum is reached (500 microns), the system is valved off and observed for 10 to 15 minutes. A rise in pressure could indicate which of the following? A. It is normal and does not indicate anything B. There may be a leak or the presence of air and/or moisture C. The system charge was not properly recovered prior to evacuation D. There may be acid or sludge in the system

B

When checking for a leak in the evaporator coil, the leak detector can be placed A. in the airstream B. in the drain outlet C. in the return D. next to the evaporator fan

B

When leak checking the suction line with an electronic leak detector, the probe should be placed A. near the receiver B. under the pipe insulation C. in the condenser air stream D. in the evaporator ai stream

B

Which of the following represents a complete list of the elements contained in HFO refrigerants? A. Hydrogen, chlorine, fluorine, and carbon B. Hydrogen, fluorine, and carbon C. Chlorine, fluorine, and carbon D. Hydrogen and carbon

D

Which of the following sets of refrigerant classifications has a zero ODP? A. CFCs and HFCs B. HCFCs and HFCs C. CFCs and HFOs D. HFOs and HFCs

A

Which of the tools used during the evacuation process can be wireless and use Bluetooth technology? A. Micron gauge B. Vacuum pump C. Core removal tool D. Evacuation hoses

C

Tropospheric ozone is A. as important to protect as stratospheric ozone B. found in the shell that extends between 7 and 30 miles above the earth's surface C. close to the earth and if often referred to as bad ozone or smog D. the ozone that protects us from harmful ultraviolet radiation

B?

Rotary compressors are built with A. both suction and discharge valves B. neither suction nor discharge valves C. only discharge valves D. only suction valves

A

Which of the following is true regarding the rotary compressor? A. There is no clearance volume on these compressors B. They are less efficient than reciprocating compressors C. They are larger than reciprocating compressors D. They rely on pistons and cylinders to compress refrigerant

D

Which of the following conditions requires a system cleanup, an oil test, and oversized filters to be added to the system? A. Noncondensables in the system B. A vibration-dependent leak in the evaporator C. A temperature-dependent leak in the compressor discharge line D. A compressor motor burnout

B

The total phaseout for all HCFC refrigerants is scheduled for the year A. 2025 B. 2030 C. 2035 D. 2040

D

The two types of heat transfer that are facilitated by the evaporator are A. superheat and subcooling B. sensible heat and superheat C. subcooling and latent heat D. sensible heat and latent heat

B

Thermostatic expansion valves are designed to maintain constant A. evaporator pressure B. evaporator superheat C. condenser pressure D. condenser subcooling

C

Two types of evacuation methods used by technicians are A. active recovery and passive recovery B. system-dependent and self-contained C. deep vacuum and triple evacuation D. nitrogen sweep and standing pressure test

C

What feature on a thermostatic expansion valve allows the system pressures to equalize during the off-cycle? A. Thermal bulb B. External equalizer line C. Bleed port D. Needle and seat assembly

A

What index takes into account the combined effects of global warming potential and ozone depletion potential? A. Total equivalent warming impact (TEWI) B. Total greenhouse effect impact (TGEI) C. Total global warming number (TGWN) D. Total equivalent greenhouse number (TEGN)

C

What is the difference between an oxygen molecule and an ozone molecule? A. An oxygen molecule has three oxygen atoms, while an ozone molecule has two B. An oxygen molecule has one oxygen atom, while an ozone molecule has two C. An oxygen molecule has two oxygen atoms, while an ozone molecule has three D. An oxygen molecule has two oxygen atoms, while an ozone molecule has one

D

Which of the following best describes the refrigerant at the outlet of the condenser? A. High-pressure vapor B. Low-pressure vapor C. Low-pressure liquid D. High-pressure liquid

D

Which of the following is a possible condenser saturation temperature for an R-410A air-conditioning system that is operating with an outside ambient temperature of 90 degrees? A. 30 degrees F B. 80 degrees F C. 90 degrees F D. 120 degrees F