ISO/R 859:1968

Testing and rating room air conditioners

ISO/R 859:1968

Name:ISO/R 859:1968   Standard name:Testing and rating room air conditioners
Standard number:ISO/R 859:1968   language:English language
Release Date:30-Sep-1968   technical committee:ISO/TC 86 - Refrigeration and air-conditioning
Drafting committee:ISO/TC 86 - Refrigeration and air-conditioning   ICS number:23.120 - Ventilators. Fans. Air-conditioners
621.56/.59 : 697.9 : 644.5 : 620.16 Ref. No. : ISO/R 859-1968 (E)
UDC
IS0
I N T ERN AT I O N A L O R G A N IZ AT I Q N F 0 R STAND A RD IZATION
I SO R ECO M M EN DATI O N
R 859
TESTING AND RATING
ROOM AIR CONDITIONERS
1st EDITION
October 1968
.
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.

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BRIEF HISTORY
The IS0 Recommendation R 859, Testing and rating room air conditioners, was drawn up by
Technical Committee ISO/TC 86, Refrigeration, the Secretariat of which is held by the British
Standards Institution (BSI).
Work on this question led to the adoption of a Draft IS0 Recommendation.
In April 1967, this Draft IS0 Recommendation (No. 1190) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial nature, by
the following Member Bodies :
Australia Hungary Switzerland
Belgium Israel United Kingdom
Canada Italy U.S.A.
Chile Korea, Rep. of U.S.S.R.
Czechoslovakia Poland Yugoslavia
France Spain
Germany Sweden
One Member Body opposed the approval of the Draft :
Japan
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council.
which decided, in October 1968, to accept it as an IS0 RECOMMENDATION.

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-4-
CON TENTS
Page
............ 5
Introduction . .
5
..... ............
1. General .
............ 7
2. Rating and test conditions . .
............ 9
.....
3. Calorimeters .
..... ............ 14
4. Instruments .
5. Cooling-capacity test . . . 15
..... ............ 18
6. Air-flow measurement .
..... ............ 22
7. Performance tests .
8. Units of measurement . 25
9. Marking provisions . 27
Air-flow diagram illustrating definitions given in clauses
Annex A.
1.3.4 to 1.2.13 . 29
Annex B. Determination of nozzle discharge coefficient . 30
Table 1. Test conditions for the determination of the cooling
capacity . 7
Maximum operating conditions . 8
Table 2.
Freeze-up test conditions . 8
Table 3.
Enclosure sweat test conditions . 9
Table 4.
Table 5. Sizes of calorimeter . 1 O
Table 6. Variations allowed in capacity test readings . 15
Table 7. Data to be recorded for cooling-capacity tests . 18
Table 8. in performance test readings . 24
Variations allowed
Table 9. Basic units of measurement and their symbols . 25
Figure 1A Calibrated room-type calorimeter . 13
Figure 1B Balanced ambient room-type calorimeter . 13
Figure 2 Pressure equalizing device . 21
Figure 3 Air-flow measuring nozzle . 21
Figure 4 Air-flow measuring apparatus . 21

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-5- ISO/R 859-1968 (I
IS0 Recommendation R 859 October 1969
TESTING AND RATING
ROOM AIR CONDITIONERS
lNTRODUCTlON
It was decided to study factory-assembled air-conditioning units within the framework of the
activities of Technical ('ointnittee ISO'TC 86 Refrigeration -~ and it has been agreed that this scope
is too broad to be covered in one IS0 Recommendation. The initial study, therefore, and the resulting
first IS0 Recommendation of this series of IS0 Recommendations, will cover only room air-con-
ditioning units with air-cooled condensers. Other types and sizes of units will be covered in later
IS0 Recommendations. Where general values are involved, the equivalents have been rounded off.
I. GENERAL
1.1 Scope
1.1.1 This 1SO Recommendation prescribes the standard conditions on which the ratings of room
air conditioners employing air-cooled condensers are based, and the methods of testing to be
applied for the determination of the various ratings.
1.1.2 This IS0 Recommendation also prescribes the test conditions and the corresponding test
procedures for determining various performance characteristics of room air conditioners.
1.1.3 This IS0 Recommendation covers only room air conditioners when used for cooling and
does not cover the performance of such room air conditioners when used for heating or
II uniid i fica t ion.
1.1.4 Room air conditioners employing water-cooled condensers are not covered by this IS0
Recommendation.
1.2 Definitions
For the purposes of this IS0 Recommendation, the following definitions apply.
1.2.1 Room air conditioner. An encased assembly designed as a unit, primarily for mounting in a
window or through the wall or as a console. It is designed primarily to provide free delivery
of conditioned air to an enclosed space, room,or zone (conditioned space). It includes a
prime source of refrigeration for cooling and dehumidification, and means for the circu-
lation and the cleaning of air. it may also include means for heating, humidifying, ventilating
or exhausting air.

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-6- ISO/R 859-1968 (E)
1.2.2 Standard barometric pressure. Barometric pressure of 1 .O1 325 bar (760 mmHg : 29.92 inHg).
1.2.3 Wet-bulb temperature. Temperature indicated when the temperature sensing element and
wetted wick have reached a state of constant temperature (evaporative equilibrium) (see
clause 4.1 S).
1.2.4 Room discharge air-flow of a unit. Rate of flow of air from the room-side outlet of the
unit.
1.2.5 Room intake air-flow of a unit. Rate of flow of air into the unit from the conditioned
space.
1.2.6 Ventilation air-flow of a unit. Rate of flow of air introduced to the conditioned space
through the unit from the outside.
1.2.7 Outdoor discharge air-flow of a unit. Rate of flow of air from the outdoor side of the unit.
1.2.8 Outdoor intake air-flow of a unit. Rate of flow of air into the unit from the outdoor side.
1.2.9 Exhaust air-flow of a unit. Rate of flow of air from the room side through the unit to the
outdoor side.
1210 Leakage air-flow. Rate of flow of air interchanged between the room side and outdoor side
through the unit as a result of its construction features and sealing techniques.
1211 Bypassed room air-flow of a unit. Flow of conditioned air directly from the room-side
outlet to the room-side inlet of the unit.
1212 Bypassed outdoor air-flow of a unit. Flow of air directly from the outdoor-side outlet to the
outdoor-side inlet of the unit.
1113 Equalizer opening air-flow. Rate of flow of air through the equalizer opening in the par-
tition wall of a calorimeter.
NOTE. ~ The definitions given in clauses 1.2.4 to 1.2.13 (inclusive) relating to air flow are illustrated in
Annex A.
1114 Net total room cooling effect of a unit. Total available capacity of the unit for removing
sensible and latent heat from the space to be conditioned.
1115 Net room dehumidifying effect (latent cooling effect). Total available capacity OÏ the unit
for removing latent heat from the space to be conditioned.
1116 Net room sensible cooling effect. Available capacity of the unit for removing sensible heat
from the space to be conditioned.
1117 Net room sensible heat ratio. Ratio of the net room sensible cooling effect to the net total
room cooling effect.
1118 Room calorimeter. Test facility consisting of two contiguous calorimeters with a common
partition. One is designated as the room-side compartment, and the other as the outdoor
compartment. Each side is equipped with instrumented reconditioning equipment whose
output may be measured and controlled to counterbalance the room-side dehumidifying and
cooling effect and the outdoor-side humidifying and heating effect of the room air condi-
tioner under test.
1119 Rated voltage. Voltage shown on the nameplate of the unit.
1220 Rated frequency(ies). Frequency(ies) shown on the nameplate of the unit.

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2. RATING AND TEST CONDITIONS
2.1 Rating conditions for the determination of the cooling-capacity
2.1.1 Test conditions stated in Table 1, columns A and B, should be considered standard rating
conditions.
2.1.2 Units manufactured for use in a climate similar to that specified in Table 1 column A only,
should have a nameplate rating determined by tests conducted at these specified conditions
and should be designated type A units.
2.1.3 Units manufactured for use in a climate similar to that specified in Table 1 column B only,
should have a nameplate rating determined by tests conducted at these specified conditions
and should be designated type B units.
2.1.4 Units manufactured for use in both types of climate defined in Table 1, columns A and B,
should have two nameplate ratings determined by tests conducted at both these specified
conditions and should be designated type AB units.
TABLE 1 ~ Test conditions for the determination of the coolingcapacity
.
r
Test conditions A B
Room air temperature
27 OC (80 OF) 29 "C (85 OF)
~ dry-bulb
"C (67 OF) 13 "C (67 OF)
wet-bulb 19
Outside air temperature
dry-bulb 35 "C (95 OF) 36 "C (1 15 OF)
- wet-bulb 24 OC (75 OF) 34 "c ( 75 OF)
Test frequency Rated frequency*
Test voltage Rated voltage**
I I
I
*
Units with dual rated frequencies should be tested at each frequency.
** Units having dual rated volttiges should be tested at the higher voltage.
2.1.5 Any capacity rating should be followed by the corresponding voltage and frequency rating.

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2.2 Maximum operating test conditions
The conditions which should be used during tests for maximum operating conditions are given
in Table 2. Tests should be carried out at conditions in column A or column B, based upon
intended use as determined in clause 2.1. For type AB units, conditions in column B apply.
Operating conditions A B
Room air temperature
32 "C (90 OF) 32 "C (90 OF)
- dry-bulb
- wet-bulb 23 OC (73 OF) 23 OC (73 OF)
Outside air temperature
43 "C (1 10 OF) 52 "C (125 OF)
- dry-bulb
31 "C ( 87 OF)
- wet-bulb 26'C( 78°F)
Test frequency Rated frequency*
and 110 "k for units with a single name-
(I) 90
plate rating.
Test voltage
(2) 95 of minimum voltage and 110 of maxi-
mum voltage for units with a dual nameplate
voltage.
*
Units with dual rated frequencies should be tested at each frequency.
2.3 ' Freeze-up conditions
The conditions which should be used during freeze-up tests for all models are given in Table 3.
Room air temperature
- dry-bulb 21 "C (70 OF)*
- wet-bulb 16 "C (60 OF)
Outside air temperature
- dry-bulb 21 OC (70 OF)
- wet-bulb 16 OC (60 OF)
~~ ~ ~~ ~ ~
Test frequency Rated frequency* *
Test voltage Rated voltage***
-
21 OC (70 OF) or the lowest temperature above 21 OC (70 OF) at which the regulating device will
allow the unit to operate.
**
Units with dual rated frequencies should be tested at each frequency.
***
Units with dual rated voltages should be tested at the higher voltage.

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2.4
Enclosure sweat test conditions
The conditions which should be used during enclosure sweat tests for all models are given in
Table 4.
TABLE 4 ~ Enclosure sweat test conditions
Room air temperature
27 "C (80 OF)
~ dry-bulb
24 "C (75 OF)
- wet-bulb
Outside air temperature
27 "C (80 OF)
~ dry-bulb
-- wet-bulb 24 "C (75 OF)
Rated frequency*
I Test frequency I I
I Test voltage I Rated voltage** I
* Units with dual rated frequencies should be tested at each frequency
** Units with dual rated voltages should be tested at the higher voltage.
2.5 Condensate disposal test conditions
as those specified for
Condensate disposal tests should be conducted at the same conditions
enclosure sweat tests (see clause 2.4).
2.6
Air-flow measuring conditions
Tests for determining air flow quantities for rating purposes should be conducted at standard
rating conditions (see Table 1). with the refrigeration means in operation and after condensate
equilibrium has been obtained.
3. CALORIMETERS
3.1
Calorimeters required for testing room air conditioners
Room air conditioners should be tested for cooling-capacity in a room calorimeter of either
calibrated or balanced-ambient type (see clauses 3.3 and 3.4).
3.2 Calorimeters - General
3.2.1 The calorimeter provids a method for determining cooling-capacity simultaneously on both
the room side and the outdoor side. The room side capacity determination is made by bal-
ancing the cooling and dehumidifying effects with measured heat and water inputs. The
outdoor-side capacity provides a confirming test of the cooling and dehumidifying effect by
balancing the heat and water rejection on the condenser side with a measured amount of
cooling medium.
3.2.2 The two calorimeter compartments, room-side and outdoor-side, are separated by an
insulated partition having an opening into which the room air conditioner is mounted. The
air conditioner should be installed using supporting members and filler pieces in a manner
similar to a normal installation. No effort should be made to seal the internal construction of
the air conditioner to prevent air leakage from the condenser side to the evaporator side or
vice versa. No connections or alterations should be made to the conditioner which might in
any way alter its normal operation.

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ISO/R 859-1968 (E)
3.2.3 A pressureequalizing device should be provided in the partition wall between the room-side
and the outdoor-side compartments to maintain a balanced pressure between these compart-
ments and also the permit measurement of leakage, exhaust, and ventilation air. This device
consists of one or more nozzles of the type shown in Figure 3, page 21, a discharge chamber
equipped with an exhaust fan, and manometers for measuring compartment and air-flow
pressures. A suggested arrangement of components is shown in Figure 2, page 21.
Since the air flow from one compartment to the other may be in either direction, two such
devices, mounted in opposite directions, or a reversible device, should be used.
The manometer pressure pick-up tubes should be so located as to be unaffected by air dis-
charged from the air conditioner on test or by the exhaust from the pressure-equalizing
device. The fan or blower which exhausts air from the discharge chamber should permit
variation of its air flow by any suitable means, such as a variable-speed drive, or a damper as
shown in Figure 2. The exhaust from this fan or blower should be such that it will not affect
the inlet air to the air conditioner on test.
The equalizing device should be adjusted during calorimeter tests or air-flow measurements
SO that the static pressure difference between the room-side and outdoor-side compartments
is not greater than 1.5 N/m2;0.015 mbar (0.153 mmH20;0.006 inH,O).
Construction details and calculations are specified in section 6.
3.2.4 The size of the calorimeter should be sufficient to avoid any restriction to intake or dis-
charge openings of the air conditioner. Perforated plates or other suitable grilles should be
provided at the discharge openings from the reconditioning equipment to avoid face velo-
cities exceeding 0.5 mis (98.3 ftlmin). Sufficient space should be allowed in front of any
inlet or discharge grilles of the air conditioner to avoid interference with the air flow.
Minimum distance from the air conditioner to side walls or ceiling of the compartment(s)
should be 1 m (3 ft), except for the back of a console-type room air conditioner, which
should be in normal relation to the wall. Table 5 gives the suggested dimensions for the
calorimeter.
TABLE 5 - Sizes of calorimeter
I
t
Suggested minimum inside dimensions
Maximum rated cooling
of each room of calorimeter
capacity of unit*
Width Height Depth
3 O00 w
2.4 m 2.1 m 1.8 m
( 2 500 kcal/h)
(10 O00 Btu/h)
( 8 ft) (7 ft) ( 6 ft)
6 O00 W
2.4 m 7.1 m 2.4 m
( 5 O00 kcal/h)
(20 O00 Btu/h)
( 8 ft) (7 ft) ( 8 ft)
9 O00 w
2.7 m 3.4 m 3.0 m
( 7 500 kcal/h)
(30 O00 Btu/h)
( 9 ft) (8 ft) (IO ft)
12 O00 w
3.0 m 2.4 m 3.7 m
(1 O O00 kcal/h)
(40 O00 Btu/h)
(10 ft) (8 ft) (12 ft)

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3.2.5 Each compartment should be provided with reconditioning equipment to maintain specified
air flow and prescribed conditions. Reconditioning equipment for the room-side compart-
ment should consist of heaters to supply sensible heat and a humidifier to supply moisture.
The energy supply may be electric, steam, or any other than can be controlled and measured.
Reconditioning equipment for the outdoor-side compartment should provide cooling and
dehumidification. A cooling coil equipped with by-pass dampers to control the dry-bulb
temperature and supplied with variable temperature water or variable water quantity to con-
trol the wet-bulb temperature may be used. If desired, dehumidifying apparatus or reheating
apparatus, or both may be used in combination with the cooling coil. Reconditioning
equipment for both compartments should be provided with fans of sufficient capacity to
overcome the resistance of the reconditioning equipment and to circulate not less than twice
the quantity of air discharged by the air conditioner to the room side or to the outdoor side
as the case may be. In no case should the reconditioning equipment discharge less than one
compartment air change per minute.
3.2.6 Remote reading thermometers, instruments, or air-sampling tubes should be used to measure
the specified wet- and dry-bulb temperatures in both calorimeter compartments. Air sampling
should comply with clause 4.1.5. The air-sampling tube may be brought outside of the calori-
meter walls for ease in reading the thermometers, but should be sealed and insulated to
avoid air leakage and heat leakage. The sampling tube fans and fan motors should be installed
L completely within the calorimeter compartments and their electrical input included in the
load measurement. The fan motor should be located so that its heat will not cause stratifi-
cation of the air passing into the air conditioner. The fan should draw the air over the
thermometers and return the air to the same compartment in a manner that will not affect
air temperature measurements or inlet or discharge air flow of the air conditioner.
3.2. It is recognized that in both the room-side and outdoor-side compartments, temperature
gradients and air-flow patterns result from the interaction of the reconditioning equipment
and the room air conditioner being tested. Therefore, the resultant conditions are peculiar to,
and dependent upon, a given combination of compartment size, arrangement and size of
reconditioning equipment, and the air conditioners air-discharge characteristics. Accordingly,
no single location for the measurement of dry- and wet-bulb temperatures can be specified
which will be acceptable for all combinations of calorimeter facilities and room air con-
ditioners which may be tested.
It is intended that the specified test temperatures surrounding the unit being tested should
simulate as nearly as possible a normal installation of such a unit operating at ambient air
conditions identical with these specified test temperatures.
The point of measurement of specified test temperatures,both wet- and dry-bulb, should be
such that the following conditions are fulfilled :
The measured temperatures should be representative of the temperature sur-
(a)
rounding the unit, and simulate the conditions encountered in an actual appli-
cation for both room and outdoor sides as indicated above.
At the point of measurement, the temperature of air should not be affected hy
(b)
air discharged from the test unit. This makes it mandatory that the temperatures
are measured upstream of any recirculation produced by the test unit.
NOTE. - An illustration of the aim of this IS0 Recommendation is given by the following :
(U)
if the conditions of air movement and air-flow patterns in the calorimeter compartment are
favourable, the temperatures may be measured at the outlet of the reconditioning equipment.
(b) If it has been established that the unit being tested does not produce any bypassed air from
discharge to intake opening, the specified temperatures may be measured immediately upstream of
such intake opening. In this case, care should be taken to ensure that the temperature-measuring
equipment does not help or penalize the air conditioner in any way.

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ISO/R 859-1968 (E)
3.2.8 Interior surfaces of the calorimeter compartments should be of non-porous material with all
joints sealed against air and moisture leakage. Access doors should be tightly sealed against
air and moisture leakage by use of gaskets or other suitable means.
3.3 Calibrated room-type calorimeter
3.3.1 The calibrated room-type calorimeter is shown in Figure 1A. Each calorimeter, including the
separating partition, should be insulated to prevent heat leakage (including radiation) in
excess of 5 of the air conditioner capacity. It is recommended that an air space permitting
free circulation be provided under the calorimeter floor.
3.3.2 Heat leakage may be determined in either the room-side or outdoor-side compartment by the
following method.
All openings should be closed. Either compartment may be heated by electric heaters to a
temperature of at least 11 "C (20 OF) above the surrounding ambient temperature. The
ambient temperature should be maintained constant within t 1 "C (t 2 OF) outside all six
enveloping surfaces of the compartment including the separating partition. If the con-
struction of the partition is identical with that of the other walls, the heat leakage through
the partition may be determined on a proportional area basis.
3.3.3 For calibrating the heat leakage through the separating partition alone, the following pro-
cedure may be used.
A test is carried out as described above. Then the temperature of the adjoining area on the
other side of the separating partition is raised to equal the temperature in the heated com-
partment, thus eliminating heat leakage through the partition, while the 11 "C (20 OF)
differential is maintained between the heated compartment and the ambient surrounding the
other five enveloping surfaces. The difference in heat between the first test and second test
will permit determination of the leakage through the partition alone.
3.3.4 For the outdoor-side compartment equipped with means for cooling, an alternative means of
calibration may be to cool the compartment to a temperature at least 11 "C (20 OF) below
the ambient temperature (on six sides) and carry out a similar analysis.
I
3.4 Balanced ambient room-type calorimeter
3.4.1 The balanced ambient room-type calorimeter is shown in Figure 1B and is based on the
principle of maintaining the dry-bulb temperatures surrounding the particular compartment
equal to the dry-bulb temperatures maintained within that compartment. If the ambient wet-
bulb temperature is also maintained equal to that within the compartment, the vapour-
proofing provisions of clause 3.2.8 are not required.
3.4.2 The floor, ceiling and walls of the calorimeter compartments should be spaced a sufficient
distance away from the floor, ceiling and walls of the controlled areas inwhich the compart-
ments are located in order to provide uniform air temperature in the intervening space. It is
recommended that this distance be at least 0.3 m (12 in). Means should be provided to
circulate the air within the surrounding space to prevent stratification.
3.4.3 Heat leakage through the separating partition should be introduced into the heat balance
calculation and may be calibrated in accordance with clause 3.3, or may be calculated.
3.4.4 It is recommended that the floor, ceiling and walls of the calorimeter compartments be
insulated SO as to limit heat leakage (including radiation) to not more than 10 of the air
conditioner capacity, with a 11 "C (20 OF) temperature difference, or 300 W
(250 kcal/h; 1000 Btu/h) for the same temperature difference, whichever is greater, as tested
using the procedure given in clause 3.3.2.

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- 13 - ISO/R 859-1968 (E
Pressure eoualizinp device
i Air sampling tubes
13ti. I A ~ Calibrated room-type calorimeter
Controlled temperature air space Pressure equalizing device
i Air samplingtubes
FIG. 1B ~ Balanced ambient room-type calorimeter

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- 14- ISO/R 859-1968 i
4. INSTRUMENTS
4.1 Temperature-measuring instruments
4.1.1 Temperature measurements should be carried out with one or more of the following instru-
ments :
(a) mercury-in-glass thermometers;
(b) thermocouples;
(c) electric resistance thermometers.
4.1.2 Instrument accuracy should be within the following limits :
wet- and dry-bulb temperatures of reconditioned air in room-side calorimeter
(a)
compartment,? 0.05 "C (I 0.1 OF)
water temperatures, outdoor-side compartment conditioning coil, I 0.05 "C
(b)
(I 0.1 OF);
all other temperatures, I 0.3 "C (I 0.5 OF).
(c)
4.1.3 In no case should the smallest scale division of the temperature-measuring instrtment exceed
twice the specified accuracy. For example, for the specified accuracy of * 0.05 C (* 0.1 OF),
the smallest scale division should not exceed 0.1 "C (0.2 OF).
4.1.4 Where an instrument accuracy of f 0.05 "C (I 0.1 OF) is specified, the instrument should be
calibrated by comparison with a thermometer certified by a recognized authority, such as a
national standards authority.
4.1.5 In all measurements of wet-bulb temperature, sufficient wetting should be provided and
sufficient time should be allowed for the state of evaporative equilibrium to be attained.
For mercury-in-glass thermometers having a bulb diameter not over 6.5 mm (0.250 in),
temperatures should be read under conditions which ensure a minimum air velocity of
3 m/s (590 ftlmin).
For any other instrument, a sufficient air velocity should be provided to give the same
equilibrium conditions as those defined above.
4.1.6 Wherever possible, temperature-measuring instruments used to measure the change in
temperature should be arranged so that they can be readily interchanged between inlet and
outlet positions to improve accuracy.
4.1.7 Temperature of fluids within conduits should be measured by inserting the temperature-
measuring instrument directly within the fluid, or within a well inserted into the fluid. If a
glass thermometer is to be inserted directly into the fluid, it should be calibrated for the
effect of pressure.
4.1.8 Temperature-measuring instruments should be adequately shielded from radiation from any
adjacent heat sources.
4.2 Pressuremeasuring instruments
4.2.1 Accuracy of pressure-measuring instruments, not including barometers, should permit
measurements within f 1 N/mZ ; 0.01 mbar (0.1 mmH, O; 0.004 inHz O).
4.2.2 In no case should the smallest scale division of the pressure-measuring instrument exceed
twice the specified accuracy.
4.2.3 Barometric pressure should be measured by a barometer having scale markings permitting
f 0.1
readings with an accuracy within
4.3 Electrical instruments
4.3.1 Electrical measurements should be made with either of the following instruments :
(a) indicating;
(b) integrating.

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- 15 -
ISO/R 859-1968 (
4.3.2 Accuracy should be within the following limits :
Instruments used for measuring all electrical inputs to the calorimeter compartments should
of the quantity measured.
be accurate to 1.0.5
4.4 Water-flow measuring instruments
4.4.1 Volume measurements should be made with either of the following instruments having an
accuracy of f 1 of the quantity measured 1
liquid quantity meter, measuring either mass or volume;
(a)
(b) liquid flow rate meter.
4.4.2 The liquid quantity meter should employ a tank having a capacity sufficient to accumulate
the flow for at least 2 minutes.
4.5 Other instruments
4.5.1 Time interval measurements should be made with instruments whose accuracy is 1.0.2 "/,
of the quantity measured.
4.5.2 Mass measurement should be made with apparatus whose accuracy is 1. 1 of the quantity
measured.
5. COOLING-CAPACITY TEST
5.1 Requirements for the test (see Table 6)
5.1.1 Cooling-capacity test should be conducted at the test conditions established in clause 2.1, as
required by the intended application of the unit.
5.1.2 Two simultaneous methods of determining capacities should be used. One method deter-
mines the capacity on the room side, the other measures the capacity on the outdoor side.
These two simultaneous determinations should agree within 4 /, of the value obtained on
the room-side for the test to be valid.
5.1.3 The test capacity should be the sensible, latent, or total heat capacity determined on the
room-side compartment.
5.1.4 Tests should be conducted at the selected conditions with no changes in fan speed or
system resistance ma
...

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  • ISO 4252:1992

    ISO 4252:1992 - Agricultural tractors -- Operator's workplace, access and exit -- Dimensions
    09-27