Fundamentals of HVACR 3rd Edition

315 ANSWER KEY for the LABORATORY MANUAL GO BACK TO INDEX ANSWER KEY for the LABORATORY MANUAL GO BACK TO INDEX ANSWER KEY for the LABORATORY MANUAL GO BACK TO INDEX LAB 39.1 DRAW WINDOW UNIT DIAGRAM LAB 39.2 WIRE WINDOW UNIT DIAGRAM This exercise is more of a hands

295 295 295 ANSWER KEY for the LABORATORY MANUAL GO BACK TO INDEX Some of the newly developed refrigerants may have zero ozone depletion potential, however all the refrigerants will have some value for global warming. The high and low side test pressures set the highest and lowest operable limits

275 ANSWER KEY for the LABORATORY MANUAL GO BACK TO INDEX The Laboratory Manual for Fundamentals of HVACR Laboratory Manual, Second Edition, allows for different lab settings and associated equipment. Therefore answers to procedural laboratory questions will vary depending on the specific manufacturers brand of equipment used. This

1 1 1 UNIT 1 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 1-1) List some of the different ways that homes and buildings may be heated. Wood, gas, oil, electric, solar, heat pumps, and geothermal heating systems are used. Wood, gas, oil, electric, solar, heat pumps, and geothermal heating systems are used. Wood,

26 26 26 UNIT 10 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 10-1) How does atmospheric pressure affect a refrigeration gauge pressure reading? Refrigeration gauges read in psig and are calibrated to read 0 at atmospheric pressure. Changes in atmospheric pressure can change the calibration point, and affect the final

29 29 29 UNIT 11 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 11-1) List the different types of cooling mechanisms. Evaporative, thermoelectric, absorption, mechanical compression Evaporative, thermoelectric, absorption, mechanical compression Evaporative, thermoelectric, absorption, mechanical compression 11-2) Which type of cooling mechanism is used in the most applications? Compression cycle Compression cycle Compression cycle 11-3) Briefly explain the fundamental

31 31 31 UNIT 12 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 12-1) Briefly explain the fundamentals principles that make the compression- refrigeration cycle work. The refrigeration cycle is made possible by the pressure difference, which is maintained by the compressor and metering device. The compressor increases the refrigerant pressure by squeezing

34 34 34 UNIT 13 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 13-1) What is the only thing all compressors must pump? Vapor Vapor Vapor 13-2) List the major types of compressors by mechanical design. Reciprocating, rotary, scroll, screw, centrifugal 13-3) Explain the difference between a positive displacement compressor and a non- positive displacement compressor. Positive displacement compressors

38 38 38 UNIT 14 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 14-1) What is the purpose of a condenser? The purpose of a condenser coil is to reject unwanted heat from a refrigeration or air conditioning system. It does this by condensing the high pressure, high temperature gas to a

41 41 41 UNIT 15 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 15-1) What happens to the refrigerant as it passes through the metering device? The refrigerant drops in pressure and temperature as it passes through the metering device. A small portion of the refrigerant flashes to a vapor, cooling the

45 45 45 UNIT 16 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 16-1) What is the purpose of the evaporator in the refrigeration system? The evaporator absorbs heat out of the product and into the refrigeration system. The evaporator absorbs heat out of the product and into the refrigeration system. The evaporator absorbs

49 49 49 UNIT 17 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 17-1) Define refrigerant. Refrigerant is the fluid used in a refrigeration system for transferring heat. Refrigerants in mechanical refrigeration systems do this by changing their physical state. They absorb heat by evaporating from a liquid to a vapor; they

53 53 53 UNIT 18 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 18-1) What is an evaporator pressure regulator? An evaporator pressure regulator (EPR) is a refrigerant flow control device that prevents the refrigerant pressure in the evaporator from operating below a minimum value. An evaporator pressure regulator (EPR) is a refrigerant

56 56 56 UNIT 19 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 19-1) List the refrigerant characteristics that are shown on a pressure-enthalpy diagram (PH). PH diagrams show the relationship of a refrigerants pressure, heat, temperature, volume, and state. PH diagrams show the relationship of a refrigerants pressure, heat, temperature, volume, and

3 3 3 UNIT 2 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 2-1) List three student organization clubs. ACCAs student club, RSES student club, and ASHRAEs student club ACCAs student club, RSES student club, and ASHRAEs student club ACCAs student club, RSES student club, and ASHRAEs student club 2-2) What does RSES stand for? Refrigeration

60 60 60 UNIT 20 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 20-1) Who was the person that was instrumental in developing the firstCFCs? Thomas Midgley Thomas Midgley Thomas Midgley 20-2) Why it is important to review the SDS before an accident happens? So that you can act quickly and respond to the necessary first

64 64 64 UNIT 21 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 21-1) Why would a service technician need a systems temperature and pressure? To diagnose refrigerant problems To diagnose refrigerant problems To diagnose refrigerant problems 21-2) What does a temperature meter measure? The speed of molecular movement, or vibration. The speed of molecular movement, or

67 67 67 UNIT 22 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 22-1) What is the difference between pipe and tubing? Pipe is always named by its approximate inside diameter, called its nominal size. Tubing is usually measured by its outside diameter. Unlike pipe, the outside diameter of tubing is accurate. Pipe

70 70 70 UNIT 23 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 23-1) Why must proper protective clothing be worn during soldering and brazing? To protect from potential hazards created by flames: heat, ultraviolet light, sparks, and molten metal. To protect from potential hazards created by flames: heat, ultraviolet light, sparks, and

74 74 74 UNIT 24 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 24-1) What are the two major functions of refrigerant piping? The two functions of refrigerant piping are to carry refrigerant and oil. The two functions of refrigerant piping are to carry refrigerant and oil. The two functions of refrigerant piping are

78 78 78 UNIT 25 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 25-1) What is the term for slightly opening a valve? Cracking the valve Cracking the valve Cracking the valve 25-2) List three precautions when handling a gauge manifold set. Never drop or abuse the gauge manifold.Keep ports or charging lines capped when not

81 81 81 UNIT 26 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 26-1) What is the significance of the Montreal Protocol? The Montreal Protocol IS AN International agreement that established target dates for the phase out of ozone depleting substances. The Montreal Protocol IS AN International agreement that established target dates for

85 85 85 UNIT 27 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 27-1) What is the purpose of the pressure regulator on the nitrogen cylinder? To reduce the pressure in the nitrogen cylinder to a safe level. To reduce the pressure in the nitrogen cylinder to a safe level. To reduce the pressure

88 88 88 UNIT 28 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 28-1) What chemicals should be inside a refrigeration system? Refrigerant and refrigeration oil Refrigerant and refrigeration oil Refrigerant and refrigeration oil 28-2) How are vacuum pumps rated? CFM capacity and micron blank-off pressure CFM capacity and micron blank-off pressure CFM capacity and micron blank-off pressure 28-3)

91 91 91 UNIT 29 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 29-1) Why are systems with fixed restriction metering devices critical to charge? They cannot adjust to changing conditions and they have no liquid receiver to store extra refrigerant. They cannot adjust to changing conditions and they have no liquid receiver

5 5 5 UNIT 3 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 3-1) Tell what causes accidents and how they can be eliminated on the job site. Most accidents are caused by carelessness, as well as lack of awareness of proper safety procedures. Accidents can be virtually eliminated by good working

102 102 102 UNIT 30 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 30-1) In the United States, electrical hazards cause more than deaths and injuries in the workplace every year.300 deaths and 4,000 injuries injuries in the workplace every year.300 deaths and 4,000 injuries injuries in the workplace every year. 300 deaths and 4,000

105 105 105 UNIT 31 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 31-1) Describe the basic structure of the atom. Atoms are made of small particles called protons, neutrons, and electrons. Protons are positively charged, electrons are negatively charged, and neutrons have no charge. In the center of the atom is

108 108 108 UNIT 32 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 32-1) What attraction and repulsion behavior do the north and south poles of a magnet exhibit? Like poles repel each other and opposite poles attract. Like poles repel each other and opposite poles attract. Like poles repel each other and opposite

111 111 111 UNIT 33 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 33-1) What are the three test instruments that can be used to verify no voltage is present in a de-energized circuit before beginning work? These are a non-contact proximity tester, an electrical tester, and a multimeter. These are a non-contact

114 114 114 UNIT 34 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 34-1) A fixed resistor has the following color bands - orange, red, brown, gold. What is the rated resistance? From Chart 36-4, orange = 3, red = 2, brown =1 . Resistance = 320 ohms with a 5% tolerance. From

118 118 118 UNIT 35 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 35-1) What is meant by motor torque? Torque is the twisting (or turning) force that must be developed by a motor to turn whatever it is driving. Torque is the twisting (or turning) force that must be developed by a

121 121 121 UNIT 36 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 36-1) What is a relay? A relay is an electrically operated switch that uses an electromagnet to open or close a set of electrical contacts. Normally only a small amount of current is required to energize the electromagnet. This

125 125 125 UNIT 37 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 37-1) Name the two standards organizations that publish standards for electric motors. Two organizations, the National Electrical Manufacturers Association (NEMA) and the International Electrotechnical Commission (IEC), specify standards for electric motors. NEMA standards are primarily used in the United

131 131 131 UNIT 38 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 38-1) List the different types of electrical diagrams used by HVACR manufacturers. a. ladder diagram b. schematic diagram c. component location diagramd. point to point diagrame. pictorial diagramf. label diagramg. factual diagramh. field connection diagrami. installation diagram c. component location diagramd. point

136 136 136 UNIT 39 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 39-1) What is the difference between an open loop and a closed loop control systems? An open loop control system does not affect the condition it is sensing. A closed loop control system controls the condition that it is

9 9 9 UNIT 4 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 4-1) Why is it important for an HVACR technicians tools to be clean and organized? The customer often judges a technician on the appearance of their tools. It is harder to work with poorly maintained tools, and a tool

140 140 140 UNIT 40 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 40-1) What is a communicating control system? In a communicating control system, the system components communicate over a serial network. Commands for different components can be sent over the same wires. In a communicating control system, the system components communicate

143 143 143 UNIT 41 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 41-1) List the four steps for isolating an electrical problem 1. Line voltage to the unit 2. Control voltage 2. Control voltage 2. Control voltage 3. Voltage to the nonfunctional component 4. Circuit to the nonfunctional component 4. Circuit to the nonfunctional component 4. Circuit to

147 147 147 UNIT 42 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 42-1) What three environmental conditions have the most effect on comfort? Temperature, humidity, and air movement. Temperature, humidity, and air movement. Temperature, humidity, and air movement. 42-2) List four ways the human body expels heat? Conduction Convection Radiation Evaporation Conduction Convection Radiation Evaporation Conduction Convection

151 151 151 UNIT 43 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 43-1) How does mechanical filtration work? Mechanical air filters work by passing the air and contaminants through a media. The contaminants get stuck in the fibers and the air passes through. Mechanical air filters work by passing the air and

153 153 153 UNIT 44 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 44-1) What is the difference between infiltration and exfiltration? Infiltration is air that leaks in; exfiltration is air that leaks out. Infiltration is air that leaks in; exfiltration is air that leaks out. Infiltration is air that leaks in; exfiltration is

157 157 157 UNIT 45 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 45-1) List the primary advantages of a room air conditioner. Room air conditioners are relatively low in cost, easy to install, and can be used in almost any type of structure. Room air conditioners are relatively low in cost, easy

158 158 158 45-12) What are the major disadvantages of a stand-alone air-conditioning unit? The type and location of the condenser. The type and location of the condenser. The type and location of the condenser. 45-13) Why are heat pumps often used on split systems? This is because heat can either be rejected or absorbed

164 164 164 UNIT 47 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 47-1) Why it is important to properly plan the installation of a residential split system air conditioner? Proper planning allows for an efficient and trouble-free installation. Without proper planning costly mistakes can occur, increasing the installation costs for the

166 166 166 UNIT 48 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 48-1) What standard covers ductboard and methods of connecting and sealing ductboard? Underwriters Laboratories 181 A Underwriters Laboratories 181 A Underwriters Laboratories 181 A 48-2) What standard covers flexible duct and methods of connecting and sealing flexible duct? Underwriters Laboratories 181 B Underwriters Laboratories

169 169 169 UNIT 49 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 49-1) How is the temperature drop through a DX coil on a split AC system determined? A sling or an electronic psychrometer is used to measure the return air dry bulb temperature and relative humidity. A chart supplied by

12 12 12 UNIT 5 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 5-1) What are the typical types of screws used on HVACR jobs? Typical types of screws are sheet metal screws, wood screws, and machine screws. Typical types of screws are sheet metal screws, wood screws, and machine screws. Typical types of

172 172 172 UNIT 50 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 50-1) Discuss the origin of natural gas. Decomposition of organisms trapped in sedimentation at the bottom of the sea. Converted into gas and oil through pressure and heat. Decomposition of organisms trapped in sedimentation at the bottom of the sea.

174 174 174 UNIT 51 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 51-1) List the four categories of gas fired furnaces based on flue gas temperature and pressure.Category I, Category II, Category III, and Category IV and pressure.Category I, Category II, Category III, and Category IV and pressure. Category I, Category II, Category

176 176 176 UNIT 52 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 52-1) List the four areas of an electronic control board that should be identified when troubleshooting. The input, output, board ground, and power supply. The input, output, board ground, and power supply. The input, output, board ground, and power supply. 52-2) What

179 179 179 UNIT 53 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 53-1) List the safety precautions that should be observed when starting a gas furnace. Don't turn anything on until you have inspected the furnace! Check for the presence of gas in the area around the furnace. Make sure there

182 182 182 UNIT 54 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 54-1) What is the one advantage of a standing pilot for a gas fired space heater? It does not require an outside source of electrical power to operate. It does not require an outside source of electrical power to operate. It

184 184 184 UNIT 55 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 55-1) List the grades of fuel oil and give a brief description of each type. a. No 1 - kerosene, 100% light distillates, pours like water, clear, lowest heating value of the fuel oilsb. No 2 - most common

187 187 187 UNIT 56 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 56-1) How does the refractory temperature affect the combustion efficiency? The higher the refractory temperature, the higher the combustion efficiency. The higher the refractory temperature, the higher the combustion efficiency. The higher the refractory temperature, the higher the combustion efficiency. 56-2) What

189 189 189 UNIT 57 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 57-1) What factors should be considered when selecting an oil fired furnace? furnace location - determines configurationrequired heating capacity - determines firing rate and nozzle size desired efficiencysize of air conditioning equipment furnace location - determines configurationrequired heating capacity -

192 192 192 UNIT 58 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 58-1) What is indicated by a frothy stream of oil in the oil supply line? A leak in the suction line allowing air bubbles in with theoil. A leak in the suction line allowing air bubbles in with theoil. A leak

195 195 195 UNIT 59 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 59-1) What is a restriction to be considered when installing a gas room heater? Since air for combustion is supplied from the room air, these units must be installed in a space that has sufficient infiltration to supply the

14 14 14 UNIT 6 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 6-1) What are four physical properties of objects that can be measured? Distance, area, volume, and weight Distance, area, volume, and weight Distance, area, volume, and weight 6-2) What units are used to measure area? Squared units such as square inches or square

197 197 197 UNIT 60 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 60-1) What advantages are there to adding humidity to heated air? Adding humidity allows people to feel warm at lower temperatures, saving energy. Keeping the humidity between 30% and 60% also provides health benefits like reducing bacterial and viral

199 199 199 UNIT 61 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 61-1) List three advantages of a warm air electric furnace as compared to an oil or gas furnace. It is more compact than the equivalent gas or oil furnace.Due to cooler surface temperature, it has zero clearance requirements on

201 201 201 UNIT 62 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 62-1) Why should furnaces not rest directly on the ceiling joists? The ceiling will act as a sounding board and transmit the blower sound throughout the house. The ceiling will act as a sounding board and transmit the blower sound

204 204 204 UNIT 63 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 63-1) List three ways of checking the heating elements of an electric furnace. Amperage draw, resistance check, visual inspection Amperage draw, resistance check, visual inspection Amperage draw, resistance check, visual inspection 63-2) Describe how a clamp on ammeter can be used to

206 206 206 UNIT 64 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 64-1) List the types of heat pumps available by combinations of heat source and heat sink. Air to air, water to air, air to water, water to water 64-2) Why is a heat pump called a heat pump? It moves

209 209 209 UNIT 65 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 65-1) What type of heat pump is the most common and why? Air to air heat pumps are the most common heat pumps in use today because they are generally less expensive and easier to install than other types

213 213 213 UNIT 66 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 66-1) What is the difference between a water source heat pump and an air source heat pump? Instead of two air coils, water-to-air heat pumps use one water coil and one air coil, In heating, water source systems use

216 216 216 UNIT 67 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 67-1) List the types of air source packaged heat pumps.Side discharge, bottom discharge (curb mount), or wall mount 67-1) List the types of air source packaged heat pumps.Side discharge, bottom discharge (curb mount), or wall mount 67-1) List the types

203 203 203 UNIT 68 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 68-1) What is indicated by a higher than normal temperature rise across the indoor coil in the heating cycle? Reduced airflow Reduced airflow Reduced airflow 68-2) How often should throwaway filters be checked? Once a month Once a month Once a month 68-3) Why should automotive

206 206 206 UNIT 69 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 69-1) What is the standard ceiling height in a residence? 8 feet 8 feet 8 feet 69-2) Name the two most common problems with basements. Moisture and mold growth Moisture and mold growth Moisture and mold growth 69-3) Name the reinforcement materials used in concrete slabs. Post

17 17 17 UNIT 7 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 7-1) What is matter? Anything that has mass and takes up space. Anything that has mass and takes up space. Anything that has mass and takes up space. 7-2) What is the difference between an atom and molecule? An atom is the smallest

208 208 208 UNIT 70 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 70-1) According to the Department of Energy, the combined impact of all buildings, both commercial and residential accounts for more than % of all electricity usage and % of all natural gas usage. 70% and 50% respectively 70% and 50%

211 211 211 UNIT 71 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 71-1) Define Indoor Air Quality. Indoor air quality is the state of the air contained within an enclosed building. Indoor air quality is the state of the air contained within an enclosed building. Indoor air quality is the state of the

213 213 213 71-19) What is the viral disease that certain mice can carry? Hantavirus Hantavirus Hantavirus 71-20) Why is it necessary for a HVACR technician to understand the building systems? The interaction of the building and its associated systems plays a large role in creating potential pollutant pathways. The interaction of the building and its

217 217 217 UNIT 73 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 73-1) What friction rate should be used to size a duct for a static pressure drop of 0.1 WC if the duct has a total equivalent length of 150 feet? (100/150) x 0.10 = 0.67 x 0.10 = 0.067

219 219 219 UNIT 74 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 74-1) Why are zone control systems used? Zone systems allow control over different portions of the house without installing multiple units. This improves overall comfort, saves energy, and reduces installation cost versus installing two systems. Zone systems allow control over

222 222 222 UNIT 75 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 75-1) List 6 types of measurements used to perform TAB procedures. Temperature Measurements, Enthalpy Measurements, Pressure Measurement, Air Flow, Electrical Measurements, Rotation Measuring Temperature Measurements, Enthalpy Measurements, Pressure Measurement, Air Flow, Electrical Measurements, Rotation Measuring Temperature Measurements, Enthalpy Measurements, Pressure Measurement,

225 225 225 UNIT 76 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 76-1) Define residential air conditioning. This category generally includes single family, multifamily, and low-rise multi-family private household residences. This category generally includes single family, multifamily, and low-rise multi-family private household residences. This category generally includes single family, multifamily, and low-rise multi- family

228 228 228 UNIT 77 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 77-1) Although air handler cabinets may be made of galvanized steel, there are still areas that may be subject to corrosion. Why? The sheet metal edge where the steel is cut and any scratches deeper than the galvanized surface

232 232 232 UNIT 78 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 78-1) Describe one method to determine if a ladder is correctly set up. One method is that for every 4 feet that the ladder is extended, it should be 1 foot out from the wall it is leaning against.

234 234 234 UNIT 79 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 79-1) Why is outside air mixed with return air? If only outside air was used, then the load on the heating or cooling system would be excessive. If only outside air was used, then the load on the heating or

19 19 19 UNIT 8 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 8-1) List the forms of energy used in the heating, air-conditioning, and refrigeration industry. Chemical, Thermal (Heat), Radiant (Light), Electrical, Magnetic, Mechanical Chemical, Thermal (Heat), Radiant (Light), Electrical, Magnetic, Mechanical Chemical, Thermal (Heat), Radiant (Light), Electrical, Magnetic, Mechanical 8-2) What units are

237 237 237 UNIT 80 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 80-1) What is the function of a low temperature thermostat on a packaged air handler? It will be set to shut down the fan and set off an alarm if the air temperature drops below 35F. It will be set

240 240 240 UNIT 81 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 81-1) Describe the difference between a flooded and a dry (direct expansion) type cooler. In a flooded cooler the refrigerant surrounds the outside of the tubes and the chilled water is circulated through the inside of the tubes. A

243 243 243 UNIT 82 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 82-1) Define hydronics. Hydronics can be defined as a science that utilizes water or steam to transfer heat from the source where it is produced, to an area where it can be used, through a closed system of piping. Hydronics

246 246 246 UNIT 83 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 83-1) When would a steam boiler be preferable over a hot-water-type boiler? When large amounts of heat need to be transferred, the boiler is used to produce steam. This is due to the fact that about 970 Btu/lb

248 248 248 UNIT 84 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 84-1) What are the two common mechanical draft cooling tower arrangements? Mechanical draft towers are categorized as either being induced draft or forced draft. Mechanical draft towers are categorized as either being induced draft or forced draft. Mechanical draft towers are

250 250 250 UNIT 85 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 85-1) What are three important items to consider in the design of commercial refrigeration systems? The equipment design must ensure that the quality of the product being cooled remains satisfactory, a minimum amount of energy must be used to

253 253 253 UNIT 86 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 86-1) What is the most common type of system used in traditional supermarkets? Multiple direct expansion systems (Multiplex) Multiple direct expansion systems (Multiplex) Multiple direct expansion systems (Multiplex) 86-2) How many compressors are typically found on a compressor rack? Most racks utilize more

256 256 256 UNIT 87 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 87-1) List eight applications for commercial ice machines. Restaurants, institutional kitchens, cafeterias, correctional foodservice, hotels, hospitals, theme parks, resorts, casinos, cruise ships. Restaurants, institutional kitchens, cafeterias, correctional foodservice, hotels, hospitals, theme parks, resorts, casinos, cruise ships. Restaurants, institutional kitchens, cafeterias, correctional

258 258 258 UNIT 88 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 88-1) What are the two areas into which electrical troubleshooting can be divided? 1) electrically diagnosing controls (switches, relays and contactors); and2) electrically diagnosing loads (coils, fan motors and compressors). 1) electrically diagnosing controls (switches, relays and contactors); and2) electrically

262 262 262 UNIT 89 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 89-1) List the associations that establish national standards for the HVACR industry. ARI - Air Conditioning and Refrigeration Institute ASHRAE American Society of Heating Refrigeration and Air Conditioning EngineersASME - American Society of Mechanical Engineers UL - Underwriters LaboratoriesNFPA -

22 22 22 UNIT 9 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 9-1) What is temperature? Temperature is the measure of the average kinetic energy in a substance. Temperature is the measure of the average kinetic energy in a substance. Temperature is the measure of the average kinetic energy in a substance. 9-2) What

265 265 265 UNIT 90 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 90-1) List the four phases of a planned maintenance service call. Routine maintenance, pre-start inspection, operational checks, troubleshooting Routine maintenance, pre-start inspection, operational checks, troubleshooting Routine maintenance, pre-start inspection, operational checks, troubleshooting 90-2) What is the purpose of checking the supply voltage

267 267 267 UNIT 91 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 91-1) What are the most common types of refrigeration system contaminants introduced because of improper installation? Common installation related contaminants include carbon, oxides, air, and water. Common installation related contaminants include carbon, oxides, air, and water. Common installation related contaminants include

271 271 271 UNIT 92 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX 92-1) List some common questions customers ask service technicians. How is the equipment supposed to operate? What is the equipment doing wrong?What is the root cause of the problem?What specific tests or procedures determined this? How can this be