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                                                                                             TAKe THe GuIDeD Tour        vii
LAB AUTHOR
Freddie Williams is the author of MyHVAClab and the            Year at Lanier Tech in 2010 and the Master Teacher award
program chair of the Air Conditioning Technology Department    in Hall County, Georgia, in 2010. Mr. Williams is a member of
at Lanier Technical College, with over twenty-three years      ASHRAE and RSES and holds degrees in management and
of professional experience. Mr. Williams has been a faculty    technical studies. He has extensive experience with electri-
member at Lanier Tech since 2002, teaching air condition-      cal and mechanical systems in industrial, commercial, and
ing and industrial systems. He was awarded Instructor of the   military environments.
LAB CONTRIBUTORS
ASSESSMENT CONTRIBUTORS
PICTORIAL SUPPORT
Carter Stanfield is program director of the Air Conditioning     David Skaves, P.E., has been a faculty member at the
Technology Department at Athens Technical College, where         Maine Maritime Academy since 1986 and received the
he has taught since 1976. His industry credentials include       Teaching Excellence award at the college in 2006. His career
both an RSES CM and NATE certification and a State of            background includes employment as a marine engineer on
Georgia Unrestricted Conditioned Air Contracting license. He     supertankers in the merchant marine, a production planner
graduated from the University of Georgia magna cum laude         at Maine’s Bath Iron Works Shipbuilding, and an engineer-
in 1995 with a bachelor of science degree in education.          ing consultant for combined cycle power plant performance
Mr. Stanfield believes that successful educational programs      testing throughout the United States as well as in Mexico and
are focused on what the students do. Students start with a       South America. In addition to his MBA from the University
strong background in fundamental concepts and theory and         of Maine at Orono, Professor Skaves is a registered profes-
then actively apply them to solve real problems. Practice and    sional engineer, licensed first-class stationary engineer, and
active application are the keys to students building both con-   licensed marine chief engineer. He is currently a member of
fidence and competence. For teaching tips and more, see          ASHRAE and AFE.
his HVACR blog at http://hvacrfundamentals.blogspot.com/.
                                                                                                                             ix
x   SeCTIoN 6   AIr-CoNDITIoNING SYSTeMS
Contents
x
                                                                                 CoNTeNTS       xi
               SECTION 7                                  SECTION 10
            Heating Systems                          Commercial environmental
                                                            Systems
unit 50 Principles of Combustion and
          Safety 833                             unit 76 Commercial Air-Conditioning
unit 51   Gas Furnaces 847                                 Systems 1200
unit 52   Gas Furnace Controls 864               unit 77   Fans and Air-Handling Units 1214
unit 53   Gas Furnace Installation 885           unit 78   Single-Zone Rooftop Unit
unit 54   Troubleshooting Gas Furnaces 904                 Installation 1233
unit 55   Oil-Fired Heating Systems 919          unit 79   Commercial Zoned Systems 1241
unit 56   Oil Furnace and Boiler Service 934     unit 80   Commercial Control Systems 1254
unit 57   Residential Oil Heating                unit 81   Chilled-Water Systems 1269
          Installation 952                       unit 82   Hydronic Heating Systems 1283
unit 58   Troubleshooting Oil Heating            unit 83   Boilers and Related Equipment 1301
          Systems 964                            unit 84   Cooling Towers 1314
xii   CoNTeNTS
           SECTION 11                                SECTION 12
      Commercial Refrigeration          installation, Maintenance, Service,
            Systems                             and troubleshooting
unit 85 Commercial Refrigeration        unit 89   Installation Techniques 1407
        Systems 1327
                                        unit 90   Planned Maintenance 1428
unit 86 Supermarket Equipment 1346
                                        unit 91   Refrigeration System Cleanup 1453
unit 87 Ice Machines 1370
                                        unit 92   Troubleshooting 1466
unit 88 Troubleshooting Refrigeration
        Systems 1390
                                                     Glossary     1481
                                                       index    1513
                                                    Unit 1
          Introduction to Heating, Ventilation,
           Air Conditioning, and Refrigeration
 objectives
 After completing this unit, you will be able to:              4. explain the importance of having a clean
                                                                  background.
 1. give a brief history of HVACR.
                                                               5. list the various types of HVACR jobs and explain what
 2. define environmental heating and air conditioning.
                                                                  they might do.
 3. give the advantages of freezing foods quickly.
                                                               6. list the HVACR professional organizations.
SMOKE
                                                                                                               FIRE TRENCH
                                                                    FLOOR WARMED FROM BELOW
                                                                             BY FIRE
figure 1-1 Think green! New innovative technologies will
allow some HVACR systems to operate on power supplied by      figure 1-2 Romans used fires channeled below floors as early
wind turbines.                                                heating systems.
                                                                                                                          1
2     section 1    fundamentals
VAPOR
EVAPORATION
WATER
LIQUID
HEAT IN
LIQUID TO VAPOR
                                                                  air conditioning
                                                                  The AC stands for air conditioning. Generally this is consid-
figure 1-3 Woodstove.
                                                                  ered by most people to be a way to cool a space, but as you
                                                                  will learn, this term encompasses much more. Artificially
                                                                  cooling the air in a living space dates back to the earliest
the next major step in heating technology in America was          centuries. In ancient Greece, large wet woven tapestries
the metal stove. Benjamin Franklin is credited with invent-       were hung in natural drafts so that the air flowing through
ing a cast-iron stove that was several times more efficient       and around the tapestries was cooled by the evaporating
than any other stove at that time. Many people still use          water. As the water evaporated, it would remove heat, just
decorative, efficient stoves to provide much, if not all, of      like when you perspire to remain cool (Figure 1-4). Some
their heating needs (Figure 1-3).                                 manufacturers sprayed water in factories for cooling as
      However, wood heat is only one alternative, because         early as the 1720s. Evaporative cooling is still used exten-
today there are many more choices for heating. Gas heat,          sively in residences and businesses throughout the south-
oil heat, electric heat, and solar heating systems are com-       western United States, where typical summer conditions
mon. Heat pumps that use a refrigeration system for heat-         are very hot and dry.
ing can be very efficient. Geothermal heating systems that              Ice was the primary means of cooling air for many
utilize the heat from within the earth are becoming more          years. The Romans packed ice and snow between double
popular. New, environment-friendly ideas and efficient de-        walls in the emperor’s palaces. John Gorrie patented the
signs are continually being developed, tested, operated,          first mechanical air-conditioning system in 1844. His sys-
and maintained by people just like you entering the indus-        tem was used to cool sick rooms in hospitals in Florida.
try. So you can see that just the H alone is a large and im-      The United States capitol building in Washington, DC, was
portant sector.                                                   first air conditioned using ice in 1909. Rumor has it that
                                                                  when the legislators got really involved in controversial de-
ventilation                                                       bates, more ice was required to keep the building cool. The
                                                                  phrase “tons of air conditioning” we use today came from
Next comes the V for ventilation. Before the invention of
                                                                  this era in history, when tons of ice were used for cooling
chimneys, fires were burned in the center of a room with
                                                                  (Figure 1-5).
smoke having to escape through holes in the roof. When
early homes were heated by wood fires, the smoke would
permeate the entire building. Although people were warm,                                  SOLID
the health hazards from this smoke exposure were harm-
ful. As an improvement, early Norman fireplaces in England                                              ICE
were designed to allow the smoke to escape through two
holes in the side of the building. It was obvious that some-
                                                                                                           LIQUID
thing needed to be done to improve the air quality.
      A properly ventilated building allows for the air to flow
and exchange so that harmful particulates such as those
in smoke are not allowed to accumulate. Fresh air also                                                  WATER
                                                                                 HEAT IN
brings oxygen into the space, but it becomes depleted over
time. A simple ventilation system can consist of only a fan
and some minor ductwork for transporting the air. More                            SOLID TO LIQUID
complex systems circulate air throughout entire buildings
through a vast network of ducts and blowers.                      figure 1-5 When ice melts, heat is absorbed.
                              unit 1    introduction to Heating, Ventilation, air conditioning, and refrigeration              3
tecH tip
refrigeration
Finally, the R stands for refrigeration, which is a necessary
component for most air-conditioning systems; however,
refrigeration systems are more commonly considered to
be used for keeping food cold. That is why very often you
may see the abbreviation HVAC, which implies air condi-
tioning only. The broader term HVACR includes both air
conditioning and refrigeration systems.
     The first use of refrigeration was for the preservation
of food. Ice was harvested from frozen lakes and stored for      figure 1-7 Snowblowers can produce artificial snow by
later use. Sometimes it could be kept all summer long in ice     evaporative cooling. (Courtesy of Red River Ski Area)
houses. Ice harvesting remained a flourishing industry well
into the twentieth century.                                      evaporative cooling even when the temperatures on the ski
     Archeologists have discovered that the first evidence       slopes are above freezing.
of man making ice appeared more than 3,000 years ago,                 Today, a majority of refrigeration systems use what
about 1,000 bc. Peoples living in northern Egypt, the Middle     is referred to as mechanical vapor compression. The me-
East, Pakistan, and India made ice using evaporation.            chanical process of compressing a gas to produce cooling
Archeological excavations in these regions have discovered       can be traced back to coal mines in England. Large steam-
ice-producing fields that covered several acres. The ice was     driven or water-powered compressors were used to force
produced in shallow clay plates, about the size of a saucer.     air into the deepest mines so miners could work in a safe
The water in these clay plates wept through the clay. This       atmosphere. Over long hours of operation, miners observed
water dampened the small straw mats holding the clay             the formation of ice around the air nozzles (Figure 1-8). This
plates in racks a few feet above the ground (Figure 1-6).        ice was collected and used for food preservation. The con-
The straw aided evaporative cooling of the water. Under          struction of steam-powered compressed-air plants that
the right conditions of temperature and humidity, a thin         produced ice soon followed. The first maritime refrigeration
film of ice would form overnight on each clay plate.             units were made by putting steam-powered compressors
     Producing ice in this way is also the principle be-         on sailing ships to make it possible for beef to be shipped
hind modern snow-making equipment. A snow-produc-                from Australia to England, starting in 1876.
ing machine like the one in Figure 1-7 can make snow by
                                                                 Hvacr and the refrigeration cycle Now that you have
                                                                 a better understanding of what HVACR means, it is easy to
                                                                 see that it encompasses a broad spectrum of needs and
                                                                 applications. Although the methods for heating can vary
                                                                 considerably, the majority of cooling applications are based
                                                                 on the refrigeration cycle. When ice changes to water, heat
is absorbed, which makes ice a viable refrigerant. But ice            systems today, but instead of using water, other fluids with
is hard to store and takes up a lot of space. Water is easier         different properties and lower boiling points, called refrig-
to use because it can be pumped and doesn’t need the in-              erants, are now used. This allows for much colder tempera-
sulation that ice requires. When water evaporates to vapor            tures, far below freezing. The “refrigeration cycle” therefore
it also absorbs heat, but then the water needs to be re-              continually evaporates and condenses refrigerants to ab-
placed, and this uses up a lot of water over time.                    sorb and then throw away the heat.
     If the vapor can be recovered and turned back into water,             A compressor is used like a pump to raise the pres-
then this cycle reduces the total amount of water needed              sure and circulate the refrigerant through the system
(Figure 1-9). Even so, the major disadvantage with this type of       (Figure 1-10). A condenser is used to remove heat from
evaporative cooling is that the lowest temperature that can           the refrigerant as it turns into a liquid. An expansion device
be reached is dependent on the properties of water.                   drops the pressure to allow the refrigerant to change back
     Notice that with both ice and water, it is their change of       from liquid to vapor in the evaporator. Heat is absorbed in
state that allows for heat to be absorbed. It is this import-         the evaporator and then thrown away in the condenser.
ant principle that serves as the basis for most refrigeration         The refrigerant does not wear out and circulates around
                                                                      and around during operation. Most refrigeration systems in
                                                                      use today operate using this type of cycle.
                                                                   EVAPORATOR
                                                                   (LIQUID TURNING                                      HIGH
                                                                   TO VAPOR)                                            PRESSURE
                                                                                                                        LIQUID
                                       HEAT IN
                                                                 LOW PRESSURE
                                                                 LIQUID/VAPOR
                                                                                     EXPANSION DEVICE
                                                                                    (REDUCES PRESSURE)
                             unit 1   introduction to Heating, Ventilation, air conditioning, and refrigeration                         5
tecH tip
tecH tip
Modern Heating
Central heating of homes and businesses dates back to an-
cient times, but the first commercial warm-air fan-driven
system was marketed in the 1860s. By the 1900s a num-           figure 1-11 The patent for the first apparatus for cooling air,
ber of different central warm-air systems were available for    invented by Willis Carrier.
residential and commercial applications, and in 1908, the       Source: Patent Drawing for W. H. Carrier’s Apparatus for Treating Air, The
essential elements for heating, cooling, humidifying, dehu-     National Archives Catalog
midifying, and filtering air were defined.
     Today central heating systems can use warm air, hot        Conditioned.” Dr. Carrier designed the psychrometric chart
water, steam, electric resistance, or a reverse refrigera-      as we know it today. (This chart displays the properties
tion cycle (heat pump). The basic theory for the heat pump      of air, such as temperature, humidity, and volume, and is
dates back to 1852.                                             commonly used for many HVAC applications.)
                                                                     Mass air conditioning of homes began in the late 1950s
Modern air conditioning                                         with window air conditioners. Central residential air condi-
                                                                tioning started to become popular in the mid-1960s. Today
The development of modern air conditioning is often cred-       most of us cannot imagine living in a home anywhere in the
ited to Dr. Willis Carrier. Dr. Carrier, an engineer, was       country that does not have air conditioning.
confronted with a problem facing printers. As paper was
printed with one color, the dampness in the ink caused          Modern refrigeration
the paper to stretch slightly, and it was nearly impossi-
ble for the second color to be printed without being mis-       Clarence Birdseye made another major contribution to the
aligned. Dr. Carrier determined that a means for controlling    industry. He developed the process of freezing foods in
the humidity was necessary and developed the first air-         1922. Today, supermarket freezer displays provide us with
conditioning system for the printing industry. His invention,   a variety of food products that would not be possible to
called an “Apparatus for Treating Air,” was patented in 1906    preserve any other way (Figure 1-12). In 2006, a new era
(Figure 1-11). His invention quickly found favor not only for   in eating occurred when the American public purchased
dehumidifying but also for cooling. Through the 1940s and       more heat-to-eat and thaw-to-eat foods than any other
1950s, businesses would proudly display signs reading “Air      type of food.
6         section 1   fundamentals
tecH tip
■■   entry-level helper The entry-level helper (first-              ■■   equipment operator Equipment operators are
     year apprentice) provides the senior technician with                required by local ordinance and state law to be present
     assistance installing and servicing equipment. Most                 anytime large central heating and air-conditioning
     medium and large mechanical contracting companies                   plants are in operation. Their primary responsibility is to
     use a number of helpers to assist with the installation             ensure the safe and efficient operation of these large
     and service of residential and commercial systems. A                systems. They must have a good working knowledge
     helper may be expected to assist in lifting, carrying,              of the system’s mechanical, electrical, and computer
     or placing equipment or components. He or she may                   control systems to carry out their job. They sometimes
     also run errands to pick up parts and clean up the                  need to hold a city or state license to become an
     area following installation or service. Helpers receive             operator. Equipment operators generally work by
     basic safety training, and if they will be driving, they            themselves or as part of a small crew. They often are
     must have good driving records.                                     required to have good computer skills when buildings
■■   rough-in installer The initial installation process is              have computerized building-management systems.
     referred to as rough-in. In this process the technician        ■■   facilities maintenance personnel Facilities-
     (first- through third-year apprentice) will install the             maintenance personnel are responsible for planned
     refrigerant lines, electrical lines, thermostat and control         maintenance and routine service on systems. They
     lines, duct boots, and duct run and set the indoor and              may work at a single location or have responsibilities
     outdoor units. The rough-in technician must have an                 for multiple locations, such as school systems.
     understanding of duct layout, blueprint reading, and                Facilities-maintenance personnel typically maintain
     basic hand tools and good brazing skills.                           systems and provide planned maintenance. They may
■■   start-up technician Once the system has been                        work alone or as part of a crew, depending on the size
     installed and all of the components are ready for                   of the facility. Maintenance personnel may from time
     operation, a start-up technician (fourth- and fifth-                to time have duties and responsibilities outside of the
     year apprentice) will go through the manufacturer’s                 HVACR trades, such as doing minor electrical plumbing
     recommended procedures to initially start a system.                 and carpentry projects for the upkeep of the building.
     Because much of the HVAC system has been field                 ■■   service manager A service manager is typically
     installed, this checkout procedure is essential to                  a skilled HVACR technician with several years of
     ensure safe and efficient operation. The start-up                   experience. This individual oversees the operation of a
     technician records all of the information requested                 company or maintenance department. He or she must
     by the manufacturer’s warranty. Start-up technicians                have good management skills, communication skills,
     must be skilled with electrical troubleshooting                     and technical expertise. Service managers typically
     and refrigerant charging and have good reading                      assign jobs to other technicians and employees. They
     comprehension and writing skills.                                   must then oversee these individuals’ jobs.
■■   service technician The service technician (fourth-             ■■   systems designer For small buildings, contrac-
     year apprentice to journeyman) is the individual who                tors normally size and select HVAC systems and
     provides the system owner with repair and mainte-                   equipment. There are many industry-standard sizing
     nance. Service technicians are the people who must                  and design guides available from trade associations
     be able to diagnose system problems and make the                    such as the ACCA (Air Conditioning Contractors of
     necessary repairs. Service technicians must be skilled              America). For larger buildings, mechanical, architec-
     in diagnosing electrical problems, refrigerant prob-                tural, or building services engineers may be required
     lems, and air-distribution problems.                                by law to design and specify the HVAC systems.
                                                                         Specialty mechanical contractors will work with the
                                                                         design plans to build and commission these systems.
                      tecH tip
Technology has enabled the field tech to stay in close             1.5 trade associations
contact with his service manager. This allows the highly
experienced service managers to provide assistance to              With the rapid growth and variety of interests, trade as-
technicians as they come upon new problems. The tech-              sociations naturally evolved to represent specific groups.
nician can also call upon the office to research unique            The list includes manufacturers, wholesalers, contractors,
problems to determine the best, most efficient way of              sheet metal workers, and service organizations. Each is
making the repair.                                                 important and makes a valuable contribution to the field.
                                                                   Space does not permit a detailed examination of all of
                                                                   these organizations, or all of their activities, but throughout
■■   sales HVACR sales are divided into two major cate-            the book many of these associations will be acknowledged
     gories: inside sales and outside sales. Inside sales deal     as specific subjects are covered.
     primarily with system sales to other air-conditioning
     contractors. Outside sales may be to both contractors
                                                                   certifications
     and end users. Working in outside sales or consumer
     sales requires the technician to have a good under-           Many trade associations offer training programs and compe-
     standing of cost and value of equipment so that the           tency examinations for the industry to help ensure a work-
     owner can make an informed choice.                            force of qualified technicians. In addition, the 1990 Clean
8         section 1    fundamentals
Air Act passed by the United States Congress requires that                  familiar with the Directory of Certified Refrigerant
anyone who performs maintenance, service, repair, or dis-                   Recovery/Recycling Equipment, published every March
posal that could be reasonably expected to release refrig-                  and September by AHRI.
erants must be certified. To become certified, technicians             ■■   HVACR equipment certification program. AHRI maintains
are required to pass an Environmental Protection Agency                     a certification service, which tests a wide variety of
(EPA)–approved test given by an EPA-approved certifying                     equipment and products to verify the performance de-
organization. Four different types of certifications have                   scribed by the manufacturer. Certified directories for var-
been developed to address different types of equipment. A                   ious products are published semiannually and annually.
person meeting the requirements for all four types is issued
a universal certification. This is certification process is fur-           AHRI has a full program of educational activities geared
ther described in Unit 26, Refrigerant Management.                    toward helping the nation’s vocational and technical
                                                                      schools improve and expand their education and training
                                                                      programs. Under the direction of AHRI’s education director
air-conditioning, Heating, and                                        and its Education and Training Committee, AHRI serves as
                                                                      a resource for manufacturers, school instructors, depart-
refrigeration institute (aHri)
                                                                      ment heads, and guidance counselors. In addition to this
The Air-Conditioning, Heating, and Refrigeration Institute            textbook and its companion materials, AHRI produces the
(AHRI) is a national trade association representing manu-             Bibliography of Training Aids, a career brochure, and a pro-
facturers of over 90 percent of U.S.-produced central air-            motional video for schools to use to recruit students into
conditioning, gas appliances, and commercial refrigeration            HVACR programs. Many schools around the country have
equipment. AHRI was formed in 2007/2008 when ARI (Air                 adopted the ICE competency exams as final exams for their
Conditioning and Refrigeration Institute) merged with GAMA            programs. AHRI’s most recent efforts involve participation
(Gas Appliance Manufacturers Association). ARI, now AHRI,             in developing national HVACR competency standards.
was originally formed in 1954 through a merger of two related              Having students pass the ICE competency exams and
trade associations and traces its history back to 1903 when it        training toward national competency standards will im-
started as the Ice Machine Builders Association of the United         prove the quality of installation and service. New HVACR
States. Today AHRI has over 180 companies as members.                 technicians will be better prepared, resulting in three basic
     Many services are provided by AHRI to assist HVACR               advantages:
technicians. Some of these services, which would supple-
ment this text, are as follows:                                        ■■   Limited training required for contractors
                                                                       ■■   Limited rework or repeat calls due to error
    ■■   ICE is an industry competency exam. This test is made         ■■   Limited warranty/replacement for manufacturers
         available to students of educational institutions to
         test their knowledge of fundamental and basic skills              The cost of repeat service calls, which is borne by
         necessary for entry-level HVACR technician positions.        contractors, may be reduced substantially by employing
         The information in this text covers the topics in the        properly trained technicians. Every new technician receives
         AHRI curriculum guide and would assist the student           training and serves as an apprentice for a period of time.
         in taking this examination. A directory of those who         That is essentially a period where contractors pay two peo-
         pass the examination is published nationally to assist       ple to do one job. A properly trained technician will gener-
         prospective employers in identifying job candidates.         ally require less training time and function sooner than a
    ■■   Equipment donations to schools participating in the          poorly trained technician.
         ICE competency exam. AHRI contacts industry sources               In co-sponsorship with AHRI, ASHRAE holds an an-
         having no-cost or low-cost equipment available to            nual international Air Conditioning Heating Refrigeration
         supply a school’s laboratory needs.                          Exposition, which may draw 30,000 to 50,000 people in
    ■■   Technician certification program. In accordance with         the field. Product exhibits, technical displays, and business
         EPA’s enforcement of the Clean Air Act, the sale of          seminars highlight the event.
         refrigerants is made only to those technicians who have
         been certified. AHRI is among the many approved by           american society of Heating,
         EPA to administer the test for certification. In addition,   refrigeration, and air-conditioning
         AHRI provides study material to prepare for the test.
                                                                      engineers (asHrae)
    ■■   Reclaimer certification program. EPA also requires
         certification of any processor of recovered refrigerant      The American Society of Heating, Refrigeration, and Air-
         for resale. AHRI is among those assigned by EPA to           Conditioning Engineers (ASHRAE) is an organization started
         carry out a certification program for companies that         in 1904 as the American Society of Refrigeration Engineers
         seek to reclaim refrigerants. Technicians handling           (ASRE) with seventy members. Today its membership is
         reclaimed refrigerant should become familiar with the        composed of thousands of professional engineers and
         Directory of Certified Reclaimed Refrigerants, published     technicians from all phases of the HVACR industry. ASHRAE
         every March and September by AHRI.                           also creates equipment standards for the industry. Its most
    ■■   Certification program for equipment used to recover          important contribution probably has been a series of four
         and recycle refrigerant. AHRI is one of the companies        books that have become the reference books of the indus-
         approved by EPA to certify equipment used to recover         try: HVAC Applications, Refrigeration, Fundamentals, and
         and recycle refrigerants. Technicians should become          HVAC Systems and Equipment.
                             unit 1    introduction to Heating, Ventilation, air conditioning, and refrigeration                     9
                     tecH tip
                                                                  Unit 1—sUMMary
 Becoming an active participating member in a profes-
                                                                  Since the beginning of time, people have had a desire to
 sional trade association will provide you with an oppor-
                                                                  control their environment to live and work more comfort-
 tunity to continue your HVACR education. The HVACR
                                                                  ably. That trend will not stop, and that is the good news for
 field is such a dynamic and evolving industry that to stay
                                                                  anyone entering this ever-growing, financially rewarding,
 competitive you must continually attend seminars and
                                                                  and personally satisfying field. HVACR technicians are re-
 take classes. This is a field where your success will de-
                                                                  quired to understand the theories behind designing, install-
 pend on your continued education.
                                                                  ing, and servicing a wide range of systems. This diversity
                                                                  ensures that each day on the job will be new and unique,
                                                                  ever changing, and challenging.
american society of Mechanical
engineers (asMe)
The American Society of Mechanical Engineers is an
organization composed of engineers in a wide variety of           Unit 1—review QUestions
industries. Among other functions, ASME writes standards
related to safety aspects of pressure vessels.                     1. List some of the different ways that homes and buildings may
                                                                      be heated.
air conditioning contractors of                                    2. What were some of the primary heating fuels that early civi-
                                                                      lizations used?
america (acca)
                                                                   3. When is it believed that ice was first artificially made for food
The Air Conditioning Contractors of America is a service con-         storage?
tractor’s association concerned with the education of tech-        4. How did early man make ice?
nicians and service managers with business-improvement
techniques. ACCA provides technician EPA certification.            5. Why did some manufacturers spray water in factories in the
                                                                      early 1700s?
 After completing this unit, you will be able to:                 4. explain the value of taking the Industry Competency
                                                                     Exam (ICE).
 1. list some of the most popular HVACR publications.
                                                                  5. list the items that help make for a professional
 2. explain the importance of professional certifications.
                                                                     appearance while on the job.
 3. list the eleven specialty areas of NATE specialty
                                                                  6. describe how to develop good communication with
     certification.
                                                                     the customer.
10
                                                          Unit 2   Being a Professional HVaCr teCHniCian        11
that reason, it would be a good business practice to occa-           2.5 skills Usa
sionally take a refresher course in EPA rules and regulations.
                                                                     Skills USA is a vocational industrial club for students in
                                                                     high schools, trade schools, and community colleges. Skills
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           LOW TONE ASSUMED BY HIM ON THIS OCCASION.
SECTION 3.
SECTION 4.
Such being in their eyes the danger; now comes their expedient for
the arresting of it. It is an altogether curious one: and among those
persons styled elders—all the elders—to every sincere and pious
Christian it will naturally be matter of no small satisfaction that no
one of the whole fellowship of the Apostles is to be found.
According to the description here given of it, the expedient is of such
a sort, that—but for the occasion on which it is represented as being
proposed,—scarcely would it be possible to divine what is meant;
what it was that was proposed to be done; or, whatever it was, what
could be the use or effect of it?
"Do therefore this," Acts 21:23, continues the speech attributed to
these elders, "do therefore this that we say to thee: we have four
men which have a vow on them:—Them take, and purify thyself with
them, and be at charges with them, that they may shave their
heads: and all may know that those things, whereof they were
informed, are nothing; but that thou thyself also walkest orderly and
keepest the law.—As touching the Gentiles which believe, we have
written and concluded that they observe no such thing, save only
that they keep themselves from things offered to idols, and from
blood and from fornication.—Then Paul," it is added, "took the men,
and the next day purifying himself with them entered into the
temple to signify the accomplishment of the days of purification,
until that an offering should be offered for every one of them."
In the terms of the historian, the matter of the accusation in
question is this: namely, "that thou," speaking to Paul, "teachest all
the Jews which are among the Gentiles to forsake Moses": it then
divides itself into two branches: one is—that "they ought not to
circumcise their children"; the other is—that "they ought not to walk
after the customs":—i. e., conform to any part of the habitual
observances—acts and forbearances together—prescribed by the
Mosaic law.
Such is the accusation: such the act charged upon him, in the
character of an offence:—the teaching of the doctrine in question.
In regard to the question—whether the doctrine he is thus said to
have taught, had really ever been taught by him,—much will depend
upon the difference between simple permission and prohibition: in
English, upon the difference between need not and ought not. If,—in
the doctrine, the teaching of which is thus charged upon him as a
crime,—simple permission was included—if, in speaking of the
converts in question, the saying was—that they need not circumcise
their children—that they need not walk after these customs—this
and no more;—in this case, that the charge, such as it is, was true,
is altogether out of doubt:—if, on the other hand, the act he was
charged with, went so far as to the teaching that they ought not to
circumcise any of their children, or that they ought not to walk after
the customs prescribed in the Mosaic law—on this supposition, the
truth of the charge will at any rate not be quite so clear as in the
other case.
According to the English translation, that which is charged as an
offence, was not committed, unless, in the doctrine taught, a direct
prohibition was contained: to a doctrine importing nothing more
than a simple permission to abstain from the acts and forbearances
in question, the charge would not have any application. Not thus
unambiguous, however, is the Greek original; either by prohibition,
or by ample permission, might the doctrine charged as criminal have
been taught.
Such is the description of the obnoxious practice, with which Paul is
here stated as having been charged: the practice by which the
odium is stated as having been incurred.
But this imaginary guilt, in what view do they mention it as imputed
to him? In this view evidently, viz., that at their recommendation he
may take that course, by which, in their view, he will escape from
the wrath of which he had become the object. The effect thus aimed
at is,—that the indignation of which he is the object, may be made
to cease. How made to cease? in one or other of two ways: for the
nature of the case admits not of any other: either by proving that
that which he had been supposed to have taught, had not in truth
ever been taught by him, and thus, that no such offence as he was
charged with, had, in fact, ever been committed by him; or that, if
any such offence had been committed, the practice recommended
might be accepted as an atonement: or rather as an assurance, that
whatever in his past conduct had given them offence, would not be
repeated by him in future.
When the supposed remedial practice has been explained,—then
immediately after comes, we see, a more particular indication of the
good effects, for the production of which it is recommended. These
are—in the first place, that, whatsoever were the doctrines he was
charged with having taught it, it will be generally known that no
such doctrines were ever taught by him: in the next place, that it will
in like manner be known, that by himself no such habitual offence as
that of an habitual violation of the law in question was committed.
Such are the effects, stated as resulting from his performing the
ceremony, the performance of which was thus recommended to him.
This ceremony we see: and what we see at the same time is—that it
could not be, in the nature of it, productive of any such effects.
Here is a certain doctrine, which he had been charged with having
taught. If the case was, that he had taught it; let him have purified
himself ever so purely, whatsoever was meant by purification,—let
him have purified himself ever so completely, let him have paid ever
so much money, let him have shaved his head ever so close,—by
any, or all of all these supposed meritorious acts, how could that be
caused, not to have happened, which in fact had happened? by what
means could they afford proof of his performance of any ceremony,
other than those very same purification ceremonies themselves?
As to the purpose of furthering the temporal interest of the
individual in question; namely, by removing the load of odium, with
which at that time it seems he was burdened,—how far, in relation to
this object, the expedient promised to be an effectual cure, is more
than at this time we can find any ground for saying: as to any good
purposes of any other kind, that it was not in the nature of it to be
productive of any, may be pronounced without much danger of error.
Here at any rate was a ceremony—a ceremony the object of which
was—to apply, to the purpose of ensuring obsequiousness, the
power of the religious sanction.
The object, to which it was meant to apply that form, comes, it may
be seen, under the general denomination of an oath. An oath is
either assertory or promissory: if it be an oath of the promissory
kind, it is called a vow. An oath which is not a vow cannot respect
anything but what is past: upon that which is past, no human act
can any longer exercise any influence. A vow has respect to
something future—to the future conduct of him by whom the vow is
taken: and to this conduct a man, in and by the taking of the vow,
engages to give the form therein mentioned.
Whatsoever, therefore, these ceremonies were in themselves,—thus
much seems plain enough, respecting the immediate effect they
were designed to answer: namely, either the delivery of a certain
species of evidence, or the entering into an engagement to a certain
effect: the evidence being a denial of the act charged: the
engagement, a promise not to practice any acts of the sort in
question in future.
Whatsoever was the effect looked for, and intended, by the
ceremony,—thus much we know, if the historian is here to be
believed: namely, that, in conformity to the advice, Paul betook
himself to the performance of it.
But, in so doing, thus much also we know: namely, that he
consented to, and betook himself to one of two things: an act of
perjury, if the effect of the ceremony was to convey an assertion,
that he had never taught, that a Jew, on being converted to the
religion of Jesus, need not circumcise his children, or walk after the
Mosaic customs: an act of apostasy, if the effect of it was an
engagement never to teach this same doctrine in future: an act of
apostasy—and for what? only to save himself from the displeasure
entertained towards him on unjust grounds by a set of ill-advised
and inconsistent disciples.
Under the general head of Paul's Doctrines, particular title Faith and
Works, it will be seen what pains he had taken, on so many
occasions, to weed out of men's breasts, Gentiles and Jews together,
all regard for the Mosaic law—to cause them, in the words of the
charge, to forsake Moses. "By the works of the law," says he in his
letter to the Galatians, Gal. 2:16, "by the works of the law shall no
flesh be justified."
In this same letter, and in the same paragraph,—he speaks, of a
speech which he had made, of a reproof which, at Antioch, he had
given to Peter:—given to him, at a point of time long before the time
here in question, namely, that of his last preceding visit—his third
visit to Jerusalem,—this being the fourth. Let us see, once more, on
what occasion, and for what cause, this reproof: we shall thereby be
the better enabled to judge—how far, supposing the ceremony to
have the effect of an assertory oath,—how far that oath can have
been conformable to the truth.
Speaking of Peter, "Time was," he says, "when he did eat with the
Gentiles: but at Antioch, as above, certain persons came from
James": Gal. 2:12, 13, and then it was that "he, Peter, withdrew and
separated himself, fearing them which were of the circumcision.—
And the Jews," continues he, "dissembled likewise with him;
insomuch that Barnabas also was carried away with their
dissimulation." Of his return to Judaism, or at any rate of the
dissimulation which accompanied it, what is the judgment which, if
he is to be believed, he pronounced? Answer, That in so doing "they
walked not uprightly according to the truth of the Gospel."
Thereupon it is, that he charged Peter with inconsistency, and
reproved him for it: "Because," says he, "he was to be blamed." Gal.
2:14. "When I saw that they walked not uprightly according to the
Gospel, I said unto Peter before them all, If thou, being a Jew, livest
after the manner of the Gentiles, and not as do the Jews, why
compellest thou the Gentiles to live as do the Jews?"
Before me lies a book by Thomas Lewis, M. A., in four 8vo volumes,
entitled Origines Hebraicae. In this book, under titles Vow and
Purification, my expectation was, to find some explanation of this
matter: as also of the other vow taken by Paul at Cenchrea, Acts
17:18, in the interval between his third visit to Jerusalem, and this
fourth: but no mention is made of either: nor does anything appear,
by which any light can be reflected upon either.
On the four men, whom, in pursuance of the recommendation in
question, Paul is said to have taken, that he might "purify himself
along with them," the intended effect of the ceremony in question is
said to be—the making or performance of a vow. But, from the
circumstance of its being a vow in their case, it follows not
absolutely that it may not have been an oath—an assertory oath, in
his case.
At Jerusalem, for the taking or performance of a vow, a man was
received into the temple:—a district more extensive by far, it
appears, than the district called Rules of the King's Bench at London:
from the account given by Lewis, as well as by this,—it appears that,
on every such occasion, fees were taken by the priests. As to the
four men here in question—having already, as it is stated, a vow on
them, but nothing as yet done in consequence,—it looks as if it had
been by poverty that they had hitherto been kept from the
accomplishment of their purpose: on which supposition, Paul being
the head of a considerable party, and as such having a command of
money,—part of the recommendation seems to have been—that, to
acquire the reputation of liberality, he should open his purse to these
his proposed companions, and pay their fees.
On the occasion here in question, whatsoever was the purpose and
intended effect of the ceremony, what appears from verse 27, Acts
27, is—that seven days were regarded as necessary for the
accomplishment of it: no mention of this in Lewis.
On this occasion, by the author of the Acts, once more is mentioned
the conciliatory decree of the Apostles and Elders. Still, not a syllable
about it is to be found in any Epistle of Saint Paul, or in any other of
the Apostolical Epistles that have come down to us.
Humanly speaking,—in what motives, in what circumstances, in what
considerations, shall we say, that the causes, final and efficient, of
this temperament—this mezzo termino—this middle course—are to
be found? The answer that presents itself is as follows:
Two stumbling-blocks were to be steered clear of:—the scruples of
the Jewish converts, and the refractoriness of the Gentiles. So far as
regarded abstinence from idolatrous feasts, and from meat with the
whole blood in it, killed and dressed in a manner other than that in
practice among the Jews,—conformity, it was judged, need not be
dispensed of, at the hands of the Gentiles: and, so long as they
would be content with meat killed and dressed after the Jewish
mode,—the Jewish teachers might, without giving offence to their
Jewish converts, have the convenience of partaking of the tables of
the Gentile converts. As to the rest—the endless train of habitual
observances, by which so large a portion of a man's life was
occupied and tormented, neither these permanent plagues, nor the
initiatory plague of circumcision, though the affair of a minute, and
performed once for all, were found endurable: neither upon himself
nor upon his children would a man submit to have it practiced.
After all, if the author of the Acts is to be believed,—it was by the
Jews of Asia, and not by those of Jerusalem, that, at Jerusalem, the
tumult was raised, by which this purification of Paul's was rendered
incomplete, and his stay at Jerusalem cut short: he being removed
for trial to Rome; at which place the history leaves him and
concludes.
Of the behaviour observed by the Jerusalem Christians, on that
occasion—Apostles, Elders, Deacons and ordinary brethren all
together—nothing is said. Yet, of these there were many thousands
on the spot, Acts 21:20: all of them of course informed of the place
—the holy place,—in which, at the recommendation of the Elders,
Paul had stationed himself. By the Jews of Asia were "all the people
on this occasion stirred up," Acts 21:27: yet, among so many
thousands, no protection, nor any endeavour to afford him
protection, for aught that appears, did he experience. Yet Asia it
was, that had been, to the exclusion of Judaea, the theatre of his
labours: from Asia it was, that the train of attendants he brought
with him, were come—were come with him to these brethren—"the
brethren,"—as if it had been said, all the brethren,—by whom,
according to the author of the Acts, they were "received so gladly."
At this period ends all that, on the present occasion, it will be
necessary to say, of this last recorded visit to Jerusalem. Of the two
inconsistent accounts said to have been given by him of his
conversion—one to the Jerusalem mob, the other to King Agrippa—
full notice has been taken under the head of his conversion: of the
miracles ascribed to him at Malta, mention is here made, in the
chapter allotted to the history of his supposed miracles. Of any other
subsequent acts or sayings of his, no notice will require to be taken
in this place. The matter here in question has been—the sort of
relation, stated as having had place, between this self-constituted
Apostle, and those who beyond controversy were constituted such
by, and lived as such with, Jesus himself: and to this have
incidentally been added the causes, which have continually been
presenting themselves, for suspicion, in respect of the verity and
authenticity, or both, of the history, which, under the name of the
Acts of the Apostles, has come down to us, connected by the
operations of the bookbinder, in the same volume with the several
histories of the four Evangelists, and the Epistles—not only of Paul
himself but of others among the Apostles; and with the work styled,
as if in derision, "The Revelations."
SECTION 5.
SECTION 6.
SECTION 1.
SECTION 2.
                           FOOTNOTES:
      [55] On this occasion, supposing the purpose of this ceremony to
      be, as here contended, no other than that of applying, to a
      declaration concerning a matter of fact, the supernatural penal
      sanction, by which it was converted into an oath,—a natural
      enough subject of inquiry is—to what cause is to be attributed the
      extraordinary length thus given to it?—seven days at the least; to
      which, upon examination, would be found virtually added, as
much greater a length of time, as the holy person, to whose
custody the oath-taker consigned himself, might be pleased to
prescribe. Answer, without difficulty,—the affording time and
pretence for the exaction of his surplice fees:—namely, those
established by law,—with the addition of others, to as large an
amount, as the need which the oath-taker had of the
accommodation thus to be afforded to him, could engage him to
submit to. As to the length of time,—in the passage in question,
the translation exhibits some obscurity: nor is it altogether
cleared up by the original. A determinate number of days, to wit,
seven, is indeed mentioned, ver. 27, but immediately before this,
ver. 26, comes a passage, from whence it seems unquestionable,
that, whatever were the time a man had been thus detained, he
was not to be let out, until, over and above what good things it
had been made necessary he should bring in with him, a further
payment, and as it should seem, in a pecuniary shape, had been
made: "to signify," says ver. 26, "the accomplishment of the days
of purification, until that an offering should be offered for every
one of them." "And when the seven days were almost ended,"
continues ver. 27: immediately after which comes the account of
the tumult, by which they were prevented from being quite
ended.
As to the phrase—"to signify the accomplishment of the days,"
what seems to be meant by it is—to make known when the
number requisite for the completion of the train of operations had
been accomplished. But, to make known when that number had
been accomplished, it was previously requisite to make known
when it had commenced: and, for making this known, the act,
probably a public one, of making entrance into the temple, was
employed.
As to the origin, as well as particular nature, of the ceremony,—
though no such word as Nazarite is here employed, on turning to
the Book of Numbers, chapter the sixth, it will be manifest, that
the ceremony here in question is the same as that, by which,
according to the receipt there given, any man whatever, whether,
and any woman also, must be left to conjecture, might be
converted into a Nazarite. Nazarite is from a Hebrew word, which
meant originally neither more nor less than a person separated. A
person consigned himself to the custody of "the priest of the
congregation:" or, as we should now say, the parson of the
parish. The ceremony accomplished, the patient was thereby put
into a state of appropriate sanctity: and, from this
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