Refrigeration & Air Conditioning Technology, 8e - 62

62

Section 1 Theory of Heat

some residential air-conditioning equipment call for halfounce accuracy. The electronic leak detectors are capable
of detecting leak rates down to a quarter of an ounce
per year.
Another detection system uses a high-intensity ultraviolet
lamp, Figure 3.39(H). An additive induced into the refrigerant system will show as a bright yellow-green glow under
the ultraviolet lamp at the source of the leak. After repairing
the leak and wiping the area clean with a general-purpose
cleaner, the area can be reinspected-the additive remains in
the system. Should a new leak be suspected at a later date, it
will still show as a yellow-green color under the ultraviolet
light. This system will detect leaks as small as a quarter of an
ounce per year.

3.15 THE BOILING POINT
OF THE REFRIGERANT
The boiling point of a refrigerant should be low at atmospheric pressure so that low temperatures may be obtained
without going into a vacuum. For example, R-502 can be
boiled as low as 250°F before the boiling pressure goes
into a vacuum, whereas R-12 can be boiled only as low
as 221°F before it goes into a vacuum. Water would have
to be boiled at 29.67  in. Hg vacuum just to boil at 40°F.
NOTE: When using the compound gauge below atmospheric pressure, the scale reads in reverse of the inches of mercury absolute
scale. The gauge starts at atmospheric pressure and counts down
to a perfect vacuum, called inches of mercury vacuum. When possible, design engineers avoid using refrigerants that boil below
0 psig. This is one reason why R-502 was a good choice for a lowtemperature system. When a system operates in a vacuum and a
leak occurs, the atmosphere is pulled inside the system instead of
the refrigerant leaking out of the system.●✔✔✔

3.16 PUMPING CHARACTERISTICS
Pumping characteristics have to do with how much refrigerant vapor is pumped per amount of work accomplished.
Water was disqualified as a practical refrigerant for small
equipment partly for this reason. One pound of water at 40°F
has a vapor volume of 2445 ft3 compared to about 0.6 ft3
for R-22. As we will see later on, system capacity is directly
related to the number of pounds of refrigerant that are circulated through the system per unit of time. This is expressed
in units called pounds per minute, or lb/min. Since the vapor
volume of 40°F water is so high, the compressor would have
to move 2445 ft3 of vapor to move a single pound. Thus, the
compressor would have to be very large for a water system.
Modern refrigerants meet all of these requirements better
than any of the older types. Figure 3.40 presents the temperature/pressure chart for the refrigerants we have discussed.

3.17 POPULAR REFRIGERANTS
AND THEIR IMPORTANT
CHARACTERISTICS
The American National Standards Institute (ANSI) and the
American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) are responsible for naming
refrigerants and identifying their characteristics. Figure 3.41
on page 60 is an organized list of some of the more popular
refrigerants and their characteristics. For more detailed information on refrigerants, refer to Unit 9, "Refrigerant and Oil
Chemistry and Management-Recovery, Recycling, Reclaiming, and Retrofitting."
As mentioned earlier, environmental
issues like ozone depletion and global warming have forced manufacturing phaseout dates for many refrigerants. However, these
refrigerants can still be used if recovered or recycled, or if they are
in an operating refrigeration or air-conditioning system. Environmental issues and phaseout dates have made many refrigerants
very expensive due to the heavy taxes imposed, and so alternative
(environmentally friendly) refrigerants have entered the market. It
is now illegal to intentionally vent any refrigerant into the atmosphere. Stiff fines of up to $32,500 and/or imprisonment can follow.
Because of this, mandatory technician certification programs have
educated HVAC/R personnel on environmental issues, alternative
refrigerants, and legislation issues.

3.18 REFRIGERANT CYLINDER
COLOR CODES
Each type of refrigerant is contained in a cylinder or drum
that has a designated color. Following are the colors for some
of the most frequently used refrigerants:
R-407B
R-407C
R-410A
R-11
R-12
R-22
R-113
R-134a
R-401C
R-402A
R-402B

Cream
Chocolate
Rose
Orange
White
Green
Purple
Light blue
Aqua
Light brown
Green-brown

R-114
R-500
R-502
R-717
R-409A
R-123
R-401A
R-401B
R-404A
R-406A
R-407A

Dark blue
Yellow
Orchid
Silver
Tan
Light gray-blue
Coral red
Mustard yellow
Orange
Light gray-green
Bright green

Some equipment manufacturers color-code their compressors to indicate the type of refrigerant used in the system.
Figure  3.42 shows refrigerant containers for some newer
refrigerants.



Refrigeration & Air Conditioning Technology, 8e

Table of Contents for the Digital Edition of Refrigeration & Air Conditioning Technology, 8e

Contents
Refrigeration & Air Conditioning Technology, 8e - Cover1
Refrigeration & Air Conditioning Technology, 8e - Cover2
Refrigeration & Air Conditioning Technology, 8e - i
Refrigeration & Air Conditioning Technology, 8e - ii
Refrigeration & Air Conditioning Technology, 8e - iii
Refrigeration & Air Conditioning Technology, 8e - Contents
Refrigeration & Air Conditioning Technology, 8e - v
Refrigeration & Air Conditioning Technology, 8e - vi
Refrigeration & Air Conditioning Technology, 8e - vii
Refrigeration & Air Conditioning Technology, 8e - viii
Refrigeration & Air Conditioning Technology, 8e - ix
Refrigeration & Air Conditioning Technology, 8e - x
Refrigeration & Air Conditioning Technology, 8e - xi
Refrigeration & Air Conditioning Technology, 8e - xii
Refrigeration & Air Conditioning Technology, 8e - xiii
Refrigeration & Air Conditioning Technology, 8e - xiv
Refrigeration & Air Conditioning Technology, 8e - xv
Refrigeration & Air Conditioning Technology, 8e - xvi
Refrigeration & Air Conditioning Technology, 8e - xvii
Refrigeration & Air Conditioning Technology, 8e - xviii
Refrigeration & Air Conditioning Technology, 8e - xix
Refrigeration & Air Conditioning Technology, 8e - xx
Refrigeration & Air Conditioning Technology, 8e - xxi
Refrigeration & Air Conditioning Technology, 8e - xxii
Refrigeration & Air Conditioning Technology, 8e - xxiii
Refrigeration & Air Conditioning Technology, 8e - xxiv
Refrigeration & Air Conditioning Technology, 8e - 1
Refrigeration & Air Conditioning Technology, 8e - 2
Refrigeration & Air Conditioning Technology, 8e - 3
Refrigeration & Air Conditioning Technology, 8e - 4
Refrigeration & Air Conditioning Technology, 8e - 5
Refrigeration & Air Conditioning Technology, 8e - 6
Refrigeration & Air Conditioning Technology, 8e - 7
Refrigeration & Air Conditioning Technology, 8e - 8
Refrigeration & Air Conditioning Technology, 8e - 9
Refrigeration & Air Conditioning Technology, 8e - 10
Refrigeration & Air Conditioning Technology, 8e - 11
Refrigeration & Air Conditioning Technology, 8e - 12
Refrigeration & Air Conditioning Technology, 8e - 13
Refrigeration & Air Conditioning Technology, 8e - 14
Refrigeration & Air Conditioning Technology, 8e - 15
Refrigeration & Air Conditioning Technology, 8e - 16
Refrigeration & Air Conditioning Technology, 8e - 17
Refrigeration & Air Conditioning Technology, 8e - 18
Refrigeration & Air Conditioning Technology, 8e - 19
Refrigeration & Air Conditioning Technology, 8e - 20
Refrigeration & Air Conditioning Technology, 8e - 21
Refrigeration & Air Conditioning Technology, 8e - 22
Refrigeration & Air Conditioning Technology, 8e - 23
Refrigeration & Air Conditioning Technology, 8e - 24
Refrigeration & Air Conditioning Technology, 8e - 25
Refrigeration & Air Conditioning Technology, 8e - 26
Refrigeration & Air Conditioning Technology, 8e - 27
Refrigeration & Air Conditioning Technology, 8e - 28
Refrigeration & Air Conditioning Technology, 8e - 29
Refrigeration & Air Conditioning Technology, 8e - 30
Refrigeration & Air Conditioning Technology, 8e - 31
Refrigeration & Air Conditioning Technology, 8e - 32
Refrigeration & Air Conditioning Technology, 8e - 33
Refrigeration & Air Conditioning Technology, 8e - 34
Refrigeration & Air Conditioning Technology, 8e - 35
Refrigeration & Air Conditioning Technology, 8e - 36
Refrigeration & Air Conditioning Technology, 8e - 37
Refrigeration & Air Conditioning Technology, 8e - 38
Refrigeration & Air Conditioning Technology, 8e - 39
Refrigeration & Air Conditioning Technology, 8e - 40
Refrigeration & Air Conditioning Technology, 8e - 41
Refrigeration & Air Conditioning Technology, 8e - 42
Refrigeration & Air Conditioning Technology, 8e - 43
Refrigeration & Air Conditioning Technology, 8e - 44
Refrigeration & Air Conditioning Technology, 8e - 45
Refrigeration & Air Conditioning Technology, 8e - 46
Refrigeration & Air Conditioning Technology, 8e - 47
Refrigeration & Air Conditioning Technology, 8e - 48
Refrigeration & Air Conditioning Technology, 8e - 49
Refrigeration & Air Conditioning Technology, 8e - 50
Refrigeration & Air Conditioning Technology, 8e - 51
Refrigeration & Air Conditioning Technology, 8e - 52
Refrigeration & Air Conditioning Technology, 8e - 53
Refrigeration & Air Conditioning Technology, 8e - 54
Refrigeration & Air Conditioning Technology, 8e - 55
Refrigeration & Air Conditioning Technology, 8e - 56
Refrigeration & Air Conditioning Technology, 8e - 57
Refrigeration & Air Conditioning Technology, 8e - 58
Refrigeration & Air Conditioning Technology, 8e - 59
Refrigeration & Air Conditioning Technology, 8e - 60
Refrigeration & Air Conditioning Technology, 8e - 61
Refrigeration & Air Conditioning Technology, 8e - 62
Refrigeration & Air Conditioning Technology, 8e - 63
Refrigeration & Air Conditioning Technology, 8e - 64
Refrigeration & Air Conditioning Technology, 8e - 65
Refrigeration & Air Conditioning Technology, 8e - 66
Refrigeration & Air Conditioning Technology, 8e - 67
Refrigeration & Air Conditioning Technology, 8e - 68
Refrigeration & Air Conditioning Technology, 8e - 69
Refrigeration & Air Conditioning Technology, 8e - 70
Refrigeration & Air Conditioning Technology, 8e - 71
Refrigeration & Air Conditioning Technology, 8e - 72
Refrigeration & Air Conditioning Technology, 8e - 73
Refrigeration & Air Conditioning Technology, 8e - 74
Refrigeration & Air Conditioning Technology, 8e - 75
Refrigeration & Air Conditioning Technology, 8e - 76
Refrigeration & Air Conditioning Technology, 8e - 77
Refrigeration & Air Conditioning Technology, 8e - 78
Refrigeration & Air Conditioning Technology, 8e - 79
Refrigeration & Air Conditioning Technology, 8e - 80
Refrigeration & Air Conditioning Technology, 8e - 81
Refrigeration & Air Conditioning Technology, 8e - 82
Refrigeration & Air Conditioning Technology, 8e - 83
Refrigeration & Air Conditioning Technology, 8e - Cover4
http://www.nxtbook.com/nxtbooks/ngsp/autoservice5e
http://www.nxtbook.com/nxtbooks/ngsp/bodystructures13e
http://www.nxtbook.com/nxtbooks/ngsp/refrigerationactech8e
http://www.nxtbook.com/nxtbooks/ngsp/medterminology8e
http://www.nxtbook.com/nxtbooks/ngsp/naturalresources6e
http://www.nxtbook.com/nxtbooks/ngsp/heavydutytruck6e
http://www.nxtbook.com/nxtbooks/ngsp/sportsmedicine2017
http://www.nxtbook.com/nxtbooks/ngsp/agriculturalmechanics
http://www.nxtbook.com/nxtbooks/ngsp/introductoryhorticulture
http://www.nxtbook.com/nxtbooks/ngsp/basicrobotics
http://www.nxtbook.com/nxtbooks/ngsp/weldingprinciplesandapplications
http://www.nxtbook.com/nxtbooks/ngsp/delmars_electricity
http://www.nxtbook.com/nxtbooks/ngsp/modernlivestock_poultryproduction2016
http://www.nxtbook.com/nxtbooks/ngsp/introtoveterinaryscience_2016thirdedition
http://www.nxtbook.com/nxtbooks/ngsp/wildlifeandnaturalresourcemanagement_2016fourthedition
http://www.nxtbook.com/nxtbooks/ngsp/smallanimalcare_management_2016fourthedition
http://www.nxtbook.com/nxtbooks/ngsp/msoffice365_2016intro_illustrated
http://www.nxtbook.com/nxtbooks/ngsp/msoffice365_2016intermediate_illustrated
http://www.nxtbook.com/nxtbooks/ngsp/msoffice365_2016intermediate
http://www.nxtbook.com/nxtbooks/ngsp/msoffice365_2016intro
http://www.nxtbook.com/nxtbooks/ngsp/century21_10e
http://www.nxtbook.com/nxtbooks/ngsp/agriscience6
http://www.nxtbook.com/nxtbooks/ngsp/microsoftoffice2013_first
http://www.nxtbook.com/nxtbooks/ngsp/automotivetech6
http://www.nxtbook.com/nxtbooks/ngsp/dreamweaver_revealed
http://www.nxtbook.com/nxtbooks/ngsp/microsoftoffice2013_intro
http://www.nxtbookMEDIA.com