इंटरनेट
मानक
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to
information for citizens to secure access to information under the control of public authorities,
in order to promote transparency and accountability in the working of every public authority,
and whereas the attached publication of the Bureau of Indian Standards is of particular interest
to the public, particularly disadvantaged communities and those engaged in the pursuit of
education and knowledge, the attached public safety standard is made available to promote the
timely dissemination of this information in an accurate manner to the public.
“जान1 का अ+धकार, जी1 का अ+धकार”
“प0रा1 को छोड न' 5 तरफ”
“The Right to Information, The Right to Live”
“Step Out From the Old to the New”
Mazdoor Kisan Shakti Sangathan
Jawaharlal Nehru
IS 4831 (1968): Recommendation on units and symbols for
refrigeration [MED 3: Refrigeration and Air Conditioning]
“!ान $ एक न' भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह”
है”
ह
Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
(Reaffirmed 2001)
IS :
4831 - 1968
Indian Standard
RECOMMENDATION
ON UNITS AND
SYMBOLS FOR REFRIGERATION
Refrigeration
and Air Conditioning
Sectional
Representing
Chairman
5~x1
EDC 66
Committee,
Danfoss
J, C. KAPVR
(India)
Limited,
Bombay
Members
SHRI A.H. MALKANI (Altern&
to
Shri J. C. Kapur)
SHRI M&IAN
Blue Star Engineering
Bombay
T. ADVANI
SHRI R.411 D. MALANI
SHHI S. R. BNAJ
Co (Bombay)
Private
Ltd.
(,4&WZUtt’)
Ministry of Food, Agriculture, Community
Development & Co-operation
Indian Engineering .4ssociation, Bombay
Central Public Works Department, Calcutta
Shri Ram Refrigeration Industries Ltd, Hyderabad
CDR Y. P. BATRA
SHRI S. K. BHATTAC~ARYA
SHRI I<. R. CWANDRAN
SHRI S. J. Rao (Altcrriafr)
Ministry of Food, .4griculture, Community Devrlopment & Co-operation
Air Conditioning Corporation Ltd, Calcutta
SHRI H. P. DESSA
SHRI J. G. MMANGLANL
(.-lltcrr &)
1)I RUTOR OF .\IARINE E~IGINEER- Xax,al Headquarters
1st.
SHHI p. D. GI’KE
Kirloskar Brothers Ltd. Sangli
~HRI 1'.G. LELE (.-IIfrrnute)
SHRI GURPREET SINGH
.4IlIndia Cold Storages Association,
Sew Delhi
SHXI S. ii. CHAUDHVRY
SHRI
SHRI 1. P. .\cciaRwu
(AZfernatf-)
ALGERTON
HUNTINGDON
York
s;HRI H. C. &ZA (A&t’nafe)
SHRI L. S. JOSHI
SHRI J. ‘5. SEHGAL
SHRI G. K. Kae~a
LT-CO1
P. s.
India
Kirloskar
Limited,
Pneumatic
Faridabad
Co Ltd,
Poona
(dltemote)
The
Hvderabad
Allwvn Metal U’orks Limited,
Hyderabad
Defence Research 6: Dewlopment
Organization
(Jfinistq
of Defence)
KAPOOR
11.4~ C. L. SHARWA (AIlcrrratr)
SHRI S. KRISHSAN
Technical
Development
Circle,
Telegraphs, Jabalpur
SHRI H. ~.GAXTH R.40 (.4lrernof~)
SHRI S.
I”. DHAMANIA
Indian
Posts
&
(Altern&)
Konfinued m puge 16)
INDIAN
MANAK
STANDARDS
BHAVAN,
9 BAHADUR
NEW DELHI
INSTITUTION
SHAH ZAFAR
110002
MARG
IS : 4831 - 1968
Indian Standard
RECOMMENDATION
ON UNITS AND
SYMBOLS FOR REFRIGERATION
0. FOREWORD
0.1 This Indian
Standard
was adopted by the Indian Standards
Institution on 4 October
1968, after the draft finalized bJ_ the Refrigeration
.and Air Conditioning
Sectional
Committee
had been approved
bv the
Mechanical
Engineering
Division Council.
0.2 With a view, to unifving the practice followed in the country. in regal-d
to the symbols and uniis used in refrigeration
and air-conditioning
trade,
need has been felt to lay down recommendations
on the principal quantities chiefly used in the field of refrigeration
and on their symbo!s and
This standard
is largely baFcc1 on the Dmft IS0
units of measurement.
Recommendation
No. 1053 ‘ Units and symbols for refrigeration
‘.
0.3 For convenience,
certain fundamental
quantities
and their derivatives
have been included which have already been dealt with in IS : 15’10 (Part
IIT)-1961* and IS : 1890 (Part I\‘)-196lt.
The column reserved for remarks
in Table 1 provides
definitions
or explanations
of quantities
for which these are not found in IS: 1890 (Part III)-1961*
and 15: 1890
(Part
I\‘)-1961 t.
0.4 The various quantities havc been grouped in a logical order so w to
facilitate their location by the users.
In certain cases when the same
symbol may have more than one meaning,
a second symbol 1135 been
proposed.
The units are separated
into two sections,
namely,
units of
the International
System (SI) and units of other systems which are at
present very widely used.
In order to obtain the SI units which are equivalent
to other units,
conversion
factors have been included
in this
standard.
0.5 India has changed to metric system of weights and measurts.
though this standard
gives both metric and fps units, metric units
be used (fps units are for information
only).
0.6 The basic and the derived units
tions are given in IS: 3616-1966:.
of the SI system
cm quantities and units of mechanics.
tRecommendations on quantities and units of heat.
;Recommendation on the international system (SI) units.
*Recommendations
2
with
their
Alshall
defini-
IS : 4831-
l%S
1. SCOPE
1.1 This standard recommends units and symbols to be used in refngeration.
2. QUANTITIES,
SYMBOLS, DIMENSIONS AND UNITS
2.1 The quantities,
symbols, dimensions and units a.re giversin Table 1.
2.2 The conversion factors given in Table 1 shall be used as multipliers
for ’ other units ’ to obtain SI unit&%;
Example :
1 ft = O-304 8 m exactly.
3
IS : 4831 - 1968
TABLE
QUANTITY
SL
SYMBOL
SYMBOLS,
(Clause
SI UNITS
Symbol
e------ (3)
(2)
(1)
‘2
QUANTITIES,
DIMENSION
No.
1
1
Length
Area,
surface
(‘5)
(4)
1
L
metre
A
L’
rquare
m
metre
ms
3
Volume
L’
cubic
4
5
Mass
Time
M
T
kilogram
second
kit!
S
6
T-i
;:
Frequency
Rotational
speed
Density (mass density)
HZ
HZ
kg/m*
9
Specific
L’*M-i
8
hertz
hertz
kilogram per cubic
metre
cubic
mefre
per
kilogram
kilogram
per second
cubic
metre
per
second
Kelvin degree
1,0
8
Celsius degree
T
AI, A&
AT, A0
e
degree
dcg
ZL-4
volume
10
Mass flow rate
MT-’
11
Volume
L’T-’
12
Thermodynamic
or
absolute
temperature
13
Customary
ture
Temperature
rence
14
15
flow rate
temperadiffe-
Coefficient
of
line3
thermai r\nnn.ion
16
17
Coefficient 01 thermal
pressure increase
metre
mx
ma/kg
kg/s
ma/s
“K
e-1
per degree
deg-l
=Y
69’
per degree
deg-i
B
8
per degree
deg-i
=1
4
IS : 4831 - 1%8
DIMENSIONS
AND
UNITS
2.1)
OTHER
UNITS
_--2
%
same
CONVERSIOS
FACTOR
(9)
(8)
(7)
ft
foot
inch
square foot
square inch
t:
in’
revolution per minute
pound per cubic foot
cubic
fl?/lb
0.062 4
lb/h
126x10-’
ft’/h
7.865 79 x 10-’
OR
519
Lc==S/9(1?-32)
foot per pound
cubic
per hour
foot
Rankine
per hour
degree
Fahrenheit
degree
OF
Fahrenheit
degree
degF
(10)
O-304 8 exactly
O-025 4 exactly
0.092 903 0
6.451
6x10-’
exactly
28.316 8 x IO-’
16.387 1 x 10-a
0.453 592 37
ft’
in’
lb
min
h
min-r
Ib,/fP
cubic foot
cubic inch
pound
minute
hour
pound
DEFINITIONS
Am
IigblARKS
symboi
j60600
l/60
16.018 5
5/9
per Fahrenheit
degree
degF-1
915
per Fahrenheit
degree
degF-i
915
per Fahrenheit
degree
degF-r
915
Also called cycles per second
Fluid mass flowing in unit
time
Fluid volume flowing in unit
time
If ta°C. IFOF. T,“K
and
Ts’R are referring to one
and same physical
state,
the figure&. IF, Tx and 7’s
are evaluated
as &=5/9
(jr--32)=Tlr-273.15=5/
9Ts-273.15
fc=.Tx-273.15
tr= Tn -459.67
The General Conference of
Weights and hfeasures has
recommended that the word
’ degree ’ or its abbreviation
’ deg ’ should be used for
temperature
intervals
or
differences.
The abbreviations “K and “C are still
often used
or,=’ d1
i di
(Continued)
IS : 4831.1968
TABLE 1 QUANTITIES,
SL
QL'ANTITY
SY?.:BOL
SYMBOLS,
SI UNITS
DIMENSION
No.
Name
(1)
(2)
(3)
(4)
Symbol ’
(5)
(6)
18
Coefficient of compressibility
x
M-‘LT’
square metre per
newton
ma/N
19
Force
F
31LT-’
newton
N
20
Pressure
P
ML-IT-’
newton per square
metre
N/D’
21
Surface
0
MT-’
newton per metre
N/m
22
Dynamic viscosity
Y
ML-‘T-1
newton second per
square metre
S.sjm’
23
Kinematic viscosity
Y
L*T-’
square mrl-re per
n.ls
tension
WCWld
24
Work
25
Power
26
Specific work
,ML’T-’
joule
J
P
ML’T-’
watt
w
U’
L’T-’
H
6
_I:k:
IS : 4831- 1968
DIMENSIONS
AND UNITS
OTHER
Cod
UNITS
--*
square
-
S3me
Symbol
(7)
(8)
inch per pound
in*/lbf
\
CONVERSION
FACTOR
(9)
1.450 37 x10-4
force
/
,
1
dvn
kgf
lbf
bar
bar
lo-* exactly
kilogram force per square
centimctrc
normal atmosphere
kgf/cm*
98 066.5 cxtictly
ntm
101 325 es;lctly
yzo;d
lbf!ft’
47.S80 3
pound L~rrc per .quare
inch
millimetre of water
millimi~tre of mercur!
inch of water
lbf!il~
6 S94.76
mmH,O
mmHg
inH,O
9+Kl6 65 cxacl I>
133.322
249.G83
inch of mercury
inHg
3 386.39
dyne per centimetre
dyn!cm
10“ exactly
poise
kilognm
force
srcontl
per square mrtre
pound force second per
square foot
P
kgf.slm*
0.1
9.806 65 rsactlj
Ibf.s/ftl
47.880 3
stokes
St
oaoo1
ft./s
0.092 903 0
erg
k1r-h
erg
kgf.m
ft.lbf
3.6 x 10’ exactl)
10-r exactlv
9.806 65 e&tly
1.355 82
horse power
metric horse power
hp
745.700
735.499
foot pound
pound
ft.lbf/lb
kilowatt
force
foot
per
square
per second
hour
kilogram force mctre
foot pound force
force per
-
-
10G exactly
YM6 65 exact11
4.448 22
-
2.989 0
7
.
AND
(1f-V
let=
I dv
v
dyne
kilogram force
pound force
-
square
UEHNITIONS
REMARKS
0x* t
This unit is also called
’ Pascal ’
1 bar = 1 hcctopieze (bpz)
1 kgf, cm*= technical
mosphrre (at)
1 mmHf;
at-
= 1 torr
IS.., nl*= 1 kgj(m.s)
-
1 St = 1 cm*/s
1 hp = 550 ft.lbf/s
1 metric horse power =
75 kgf.mjj
The work done per unit
of mass
IS : 4831-
1968
TABLE
QuhNTITP
1
QUANTITIES,
51
DIMENSION
,
UNITS
L
Name
(4)
(2)
(1)
SYMBOLS,
Symbol
(6)
27
Heat quantity
ML’T-’
joule
J
28
Heat flow rate
ML’T+
watt
W
29
Density of heat flow
rate
MTJ
watt per square
30
Heat transfer capacity
(heat load)
ML’TJ
watt
W
31
Refxigerating capacity
MLYPI
watt
W
32
Efficiency
-
33
Indicated efficiency
-
34
Mechanical efficiency
3s
Voiumetric efficiency
8
metre
.
-
W/ma
I
-
IS : 4831.1968
DIMENSIONS
AND UNITS-
@HBR
Codd
UNITS
CONVERSION
FACTOR
--he-
DEFINITIONS
&HARKS
AND
,Xame
(7)
(9)
international kilocalorie
kilocalorie 15°C
British
thermal
unit
4 1868 exactly
4 185.5
Btu
1 055Tm
kc&z/h
l-163 exactly
Btu/h
0293 071
international kilocalorie
per hour square metre
British
thermal
unit
per hour square foot
kcahT/
(h.m*)
Btu/(h.ft’)
1.163 exactly
3.154 59
international
per hour
kcalrr:h
l-163 exactly
kilocalorie at 15°C per
hour
British thermal unit per
hour
k=l,,/h
l-162 6
Btu/h
0.293 05 1
frfgorie per hour
ton of refrigeration
fglh
ton
I.162 6
3 516.85
international kilocalorie
per hour
British thermal unit per
hour
kilocalorie
(10)
1 kWh = 859*845 kcalrr
In the refrigeration field the
unit ’ frig&e ‘, (fs) is also
used, corresponding
to an
extractron of 1 kcal,, from
the body to be cooled
1 kcal,=3.968
Btu
Heat flow rate rejected to
the hot body from a refrigerating machine
1 fg/h= 1 kcal,,‘h
1 ton of refrigeration = a
heat flow rate of 3 023.95
kcal/h or 12 Ooo Btu/h removed by the refrigerating
system from the cold body
Ratio of the indicated power
of a compressor to the ideal
power with isothermal ccmpression
Ratio of the indicated power
of a compressor to the input
power
-
9
Ratio of the fluid volume
drawn in during the suction
time at the suction conditioning to the volume displaced in the cylinder or
cylinders of compressor
.^
.
..
IS : 4831- 1968
TABLE
SL
QUANTITY
SYMBOL.
1 QUANTITIES,
DIMENSION
SI
UNITS
NO.
Same
(2)
(1)
(5)
(4)
36
Isentropic
adiabatic
37
compresIsothermal
sion efficiency
38
Refrigerating
ance
39
Refrigeration
capacity
per unit volume
ML-T’
joule per cubic
metre
40
41
Internal energy
Enthalpy
Free energy
Free enthalpy
Energy
Latent heat of
formation
ML’T-”
joule
LW’
joule per kilogram
t:
2
46
47
48
49
::
efficiency of
compression
SYMBOLS,
Symbol
(6)
-
-
perform-
J/m’
J
trans-
Specific internal energy
Specific enthalpy
Specific free energy
Specific free enthalpy
Specific energy
Specific
latent
heat
of transformation
10
J/kg
IS : 48310 1968
DIMENSIONS
AND UNITS -
Cmfd
DEFBWTIONS
&MARKS
CONVERSLOX
FACTOR
Symbol-
Same
(9)
(8)
(7)
_.
international
kilocalorie
per watt hour
kcahr/Wh
1.163
British thcrmnl unit per
horse power hour
British therrnai uuit )xr
\ratt hour
‘I‘IHI of refrigeration per
horse powrr
frigorie
per
kilocxlrxic
iu ternational
kiluc;+Ic;ric
1~’ cubic mctre
Btu/hp.h
OWO 393
13tul\\'h
0.293
Ton/hp
4.716
fgikcal
kcal&m*
4 186.8 exactly
iutcrnational
AX(U
kilocalorie
{ Uritish thvrmnl unit
Ratio of the power
of
’
Ratio
of the refrigerating
sapacity to the volume flow
rate, in a ckarly
defined
condition
kcalrr
1 xu
4 186-g exactly-)
2 326 cxaLtly
’ (d .-.L-I,r\-T~
(s-.\,I
1
(CohIurd)
11
an
isentropic compression (reversible adiabatic)
to the
actual power supplied to
the same fluid mass flow
rate from the initial to the
final state (enthalpies difference)
Ratio of the power with reversible
isothermal
compression to the actual power
supplied to the same fluid
mass flow rate from the
initial to the fina. state
Ratio
of the refrigerating
capacity
to the absorbed
po\j.er (for
a cycle,
a
machine, a compressor, ctc)
IS: 4831 - 1968
TABLE
QUANTITY
SL
NO.
(2)
52
Specific
53
Relative
54
Saturation
55
Entropy
56
Specific
57
Heat
58
59
Specific heat
Specific heat
at constant
Specific heat
at constant
61
DIMENSION
SYMBOLS,
SI UNITS
-I
(1)
60
SYMBOL
1 QUANTITIES,
humidity
(3)
(4
x
-
humidity
P
ratio
cp
entropy
capacity
capacity
capacity
pressure
capacity
volume
Specific heat capacities ratio
Name
Symbol
(5)
(6)
3
-
.-
-
-
Kelvin
J/-K
S
ML*T-%-*
joule per
degree
8
L’T-‘0-l
joule per kilogram
Kelvin degree
JlOw’K)
C
ML’T-‘8-l
joule per
degree
J ldeg
L’T-‘6-l
joule per kilogram
degree
Celsius
C
CP
cv
-
YD x
12
J/PwW
IS:4831
DIMENSIONS
I
AND UNITS
OTHER UNIIS
L
Name
- 1968
- Contd
DEFINITIONS AND
REMARKS
CONVERSION
Symbol
(7)
(8)
-
-
\
FACTOR
-
-
Ratio of the mass of moisture in humid air to the
mass of dry air present in
the mixture
Ratio of the water vapour
partial
pressure
to
the
saturation pressure of pure
water vapour at the same
temperature
Ratio of the actnal specific
humidity
to the specific
humidity
of saturated air
at the same temperature
E;ors - For temperaturesIns
than 0°C the values in general
applp to pure water ice. If it
is concerning sub-cooled water
the symbols are to be qualified
by P particulv index.
mtemational
kilocalorie
per Kel\-In degree
Britrsh thermal unit per
kcahr/‘K
4 196.8 exactly
Btu/“R
1 899 exactly
international kilocalorie
per kilogram Kel\-in
degree
British thermal unit per
I pound Rankine degree
kcal IT/
(kg.“K)
4 186.8 exactly
Btu/(lb.“R)
4 186.8 exactly
rinternational
kcalrr! deg
4 186.8 exactly?
BtuYF
1 899 exactly
kilocalorie
{ F!%?%e’~rnal
unit per
1 degree Fahrenheit
international kilocalorie
I per ki!ogram degree
British thermal unit per
pound degree Fahrcnheit
-
kcalrri
(kg.deg)
Btui
(Ib.degF)
This o,rantitv
4 186.8 exactly
4 186.8 exactly
-
I
1
J
y, x= 1:
13
is not com_
pletely defined if the type
of transformation
is not
specified
IS:4831 - 1968
TABLE
51.
QUANTITY
SYMBOL
DIMENSION
(1)
66
SYMBOLS,
SI UNlTB
r_---*-----~
?iO
65
1 QUANTITIES,
(3)
(21
O\-crpll c*vfficicnt
he.lt transfer
I’hcrmal
diffusivtty
Name
Symbol
(5)
(6)
(1)
11LT-‘9-’
watt per metre
degree
.\fT-‘B-l
watt per
L’T-’
square metrc
secolll i
of
mctre
W/(m.deg)
square
degree
\V;(m* deg)
1
tl
14
per
rn’p
IS: 43310 1968
DIMENSIONS
AND
UNITS -
contd
OTHBR UNITS
-A
c
Name
----9
[international
kilocalorie
per hour metre degree
rgritish thermal unit per
hour foot degree
Fahrenheit
rvntemational
kilocalorie
1 per hour square metrc
degree
British thermal unit per
hour square foot degree
Fahrenheit
square
square
metre per hour
foot per hour
DSFINITIONS
C~NVSRSION
Symbol
kcalm/
(h.m,deg)
l-163 exactly]
BW@.ft.
1.730 73
AND
RIZMARKS
FACTOR
I
de&V
t
where d is the total thicknwS
of a wall, and d, and Ii the
thicknesses
and conductiGties
of the wall componcllts
kcallrl
(h.nPdeg)
1.163 exactly
Btu/(h.ft’
degF)
5.678
m’ih
fPjh
0400 278
O~ooo 02s 8
15
a =I/cp
IS,: 4831 - 1968
(Cot&rued
from page 1)
Re#vesen
fing
&iembcrs
SHRI H. J. LENTIN
SIiRl R. K. MAHAJAN
Godrej & Boyce Mfg Co Pvt Ltd, Bombay
& Standards
Organization
Research,
Designs
(Ministry of Railways)
Directorate
General of Technical
Developmen+
New Delhi
SWRI D. B. MALIK
SHRI S. N. BANWET (Altarnalc)
SHRI MANMOHAS SINCH
Frick India Ltd, New Delhi
SHRI BACHAN SINGH (Aite~nale)
SHRI NAUNIHAL
SINGX
MATHUR
National Physical
Laboratorv,
New Delhi; and
Indian Society
of Refrigerating
Engineers,
Calcutta
SHRl A. P. SHIVDAS.4Nl
Indian Society of Refrigerating Engineers. Calcutta
(-4 Ilcrrtafe)
SHRI S. N. .&fUKERJI
National Test House, Calcutta
SHRI
B.
K.
$kKHERJI
(~k~~ntc)
DR P. K. PANDEY
StiRl
1’.
p.
PUTJ
SHRI 0. P. PURI
SHRI G. l’. RAO (AIleva&)
Central Mechanical Engineering Research Institute,
Durgapur
All India Air Conditioning d- Refrigeration Association, New Delhi
Voltas Limited, New Delhi
SHRI R. J. RAMRAKHIANI
Centgme,xiur
SHRI C. R. SIRCAR
Directorate
General
of Supplies
&
(Ministry of Industry t. Supply)
SHRI K. LWTT.~ (4 llrrnafc)
SHRI K. S~BRAHW~XY.~M
SHRI hl. Y. PATABKAB,
l)ircr.tllr (llcch Engg)
Assistant
I
Institute
(Ministry
Ahmedabad
Textile
Industry’s
ciation, Ahmedabad
Director General, ISI (Ex-o&icio
SHRI S. P. ABBEV
Director (Mech Engg).
16
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Disposals
Research
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