GB/T 19413-2024Air conditioning unit for data center and communication room (English PDF)

1 Scope

1 The document lays down the types and basic parameters, technical requirements, test methods, inspection rules and the marking, packaging, transport and storage of air conditioning units for data centres and communication rooms.

1 It applies to the air conditioning units, referred to below as computer room air conditioners, that provide a suitable environment for the electronic information equipment placed in data centres and communication rooms and in rooms housing computers, data processors, program-controlled exchanges, servers, network equipment and data storage devices.

3 Terms and definitions

3 The terms and definitions given in JB/T 7249, GB/T 17758 and GB 50174 apply, together with those below.

3.1 A computer room air conditioner is an air conditioning unit that provides air circulation, filtration, cooling, reheating where fitted and humidity control for the electronic information equipment concentrated in data centres, communication rooms, computer rooms and similar places.

3.2 Free cooling is the process in which a system made up of heat exchangers, fans and distribution equipment brings air, water or another cold source obtained directly from outside the room, at a temperature below that of the air inside the room, into heat exchange with the air inside the room, so as to reduce or wholly replace mechanical refrigeration.

3.3 to 3.5 A compressor refrigeration type computer room air conditioner obtains its cooling capacity from the vapour compression refrigeration cycle alone. A composite refrigeration type unit has at least two modes of operation, compressor refrigeration and free cooling. A chilled-water type unit obtains its cooling capacity from chilled water below room temperature supplied by an external cold source, which a note explains to be equipment such as a water chiller or a cooling tower.

3.6 and 3.7 A dry cooler is a heat exchanger in which the fluid that has exchanged heat with the air inside the room exchanges heat with air obtained directly from outside the room; three notes give its abbreviated name, state that the cooled fluid may serve either as the cooling medium of the condenser of the refrigeration system or to cool the air inside the room, and name it a glycol dry cooler when the fluid inside the tubes is a glycol solution. An economic cooler is a heat exchanger in which the air inside the room exchanges heat with the fluid that has exchanged heat with air obtained directly from outside the room.

3.8 A thermosyphon loop is a device in which, by virtue of the difference in height and in density between condenser and evaporator or by means of a refrigerant pump or other motive equipment, the refrigerant circulates in a closed loop and transfers heat by evaporation and condensation. A note abbreviates it to heat pipe and includes both gravity and pumped heat pipes.

3.9 to 3.12 Standard rating conditions are one operating condition, or a set of them, laid down in the document to establish a comparable basis. Air flow is the volume of air, in the actual air state, that the unit delivers to the room in unit time under the stated test conditions, in cubic metres per hour. Sensible cooling capacity is the sensible heat removed from the room in unit time, and cooling capacity the total heat removed from the room in unit time, both in watts or kilowatts and both under the stated test conditions; a note adds that different conditions give different cooling capacities, the one measured at the nominal cooling condition being called the nominal cooling capacity.

3.13 to 3.15 Sensible heat ratio is the ratio of sensible cooling capacity to cooling capacity under the stated cooling capacity test conditions, reported to two decimal places. Cooling power input is the total power consumed by the unit in operation under those conditions. Energy efficiency ratio, EER, is the ratio of cooling capacity to cooling power input, in watts per watt or kilowatts per kilowatt and reported to two decimal places, or to three when it is used as an intermediate value; notes add that the value calculated with the sensible cooling capacity is the sensible energy efficiency ratio EERS, and that the values at part load are called the part load energy efficiency ratio PEER and the part load sensible energy efficiency ratio PEERS.

3.16 and 3.17 Energy efficiency coefficient, EEC, is the ratio, for a chilled-water type unit under the stated cooling capacity test conditions, of the cooling capacity to the sum of the total power consumed and the electrical power equivalent of the water resistance, reported to two decimal places; the value calculated with the sensible cooling capacity is the sensible energy efficiency coefficient EECS. Cold-air ratio is the ratio of cooling capacity to air flow under the stated test conditions, in watts per cubic metre per hour and reported to one decimal place.

3.18 to 3.20 Annual energy efficiency ratio, AEER, is the ratio of the total heat removed from the room over a year of cooling operation to the total electricity consumed, in watt hours per watt hour and reported to two decimal places, the value calculated with the sensible energy efficiency ratio being the sensible annual energy efficiency ratio AEERS. Part load ratio is the ratio of the measured nominal cooling capacity to the declared value when the capacity control device, where fitted, is set at the position corresponding to part load, expressed as a percentage, full load being the state that gives the declared nominal cooling capacity and corresponding to a ratio of 100%. Part load annual energy efficiency ratio, PAEER, is the corresponding annual ratio at a particular part load ratio, which is normally agreed with the customer.

4 Types and basic parameters

4.1 Units are classified by construction as integral or split; by position relative to the servers as room level, in-row or rack level, the last two being abbreviated to in-row air conditioner and rack air conditioner; by the direction of supply air as upflow, horizontal flow or downflow; by return air temperature as the standard return air temperature type or the low return air temperature type; by capacity control as fixed capacity or variable capacity; and by product kind as compressor refrigeration type, subdivided into air-cooled, water-cooled and evaporatively cooled, composite refrigeration type, subdivided into heat pipe composite, glycol economic cooler composite and indirect evaporative cooling composite, and chilled-water type, subdivided into coil type and water-cooled heat pipe type. Together with the water-delivering products, these types make up the product standard system for the cooling equipment used in data centres and communication rooms, the standards followed by the typical products being given in Annex A.

4.2 The model designation may be settled by the manufacturer, but is to convey the cooling capability of the unit at the nominal condition; a note allows that capability to be an approximation of the nominal cooling capacity.

4.3.1 The unit is to work normally under the conditions of Table 1. The indoor dry-bulb temperature range is 5 °C to 45 °C and the indoor relative humidity range 8% to 80%, both common to all three product kinds. The outdoor dry-bulb temperature range is -15 °C to 45 °C for the compressor refrigeration type and -35 °C to 45 °C for the composite refrigeration type, and is not applicable to the chilled-water type. The entering water temperature range is 7 °C to 34 °C for the compressor refrigeration type, 4 °C to 34 °C for the composite refrigeration type and 5 °C to 35 °C for the chilled-water type. The altitude is not to exceed 1000 m. Where the unit is used beyond these conditions, the manufacturer is to declare the fact and agree with the user on additional measures or on derating.

4.3.2 The test conditions of indirect evaporative cooling units follow JB/T 14641 and JB/T 14643. For other kinds, the standard conditions for the general performance tests are set in Tables 2, 3, 4 and 5 and those for the annual energy efficiency tests in Tables 6 and 7. Tables 2 to 7 set out, for each condition type such as nominal cooling, maximum load cooling, low temperature cooling, condensation, humidification capacity and reheating capacity, and for each unit mode and return air temperature type, the dry-bulb and wet-bulb temperatures on the using side and the dry-bulb, entering water, leaving water or glycol temperatures on the heat source side. In the extracted text the headings and the values of these six tables are destacked and cannot be matched to one another with confidence, so the individual temperatures are not reproduced here; footnotes to them state that the make-up water temperature on the heat source side of an evaporatively cooled unit is 15 °C to 30 °C during the test, that the water or liquid flow is held the same as at the nominal cooling condition, that a temperature recommended by the manufacturer is used where it is more severe than the one tabulated, and that the humidification condition applies when a wetted-film humidifier is used.

4.3.2 The external static pressure for both the general performance test and the annual energy efficiency test is 75 Pa for an upflow room level unit, 0 Pa for a horizontal flow room level unit and 20 Pa for a downflow room level unit; 0 Pa for an in-row unit; and 10 Pa for a rack level unit. A note allows a unit whose declared nominal cooling capacity was designed for conditions other than the nominal cooling condition of the document to be tested at the nominal condition declared by the manufacturer, using the test methods of the document.

5 Technical requirements

5.1 The general requirements are that the unit be made to drawings and technical documents approved by the prescribed procedure; that ferrous parts be given an anti-rust treatment; that electroplated surfaces be smooth and even in colour and free of peeling, exposed base metal, pinholes, obvious mottling and scratches, and that after the salt spray test of 6.23.1 no single rust spot or rust mark on the plated layer exceed 1 square millimetre in area, that there be not more than two rust spots or marks per 100 square centimetres of specimen and none at all on a specimen smaller than 100 square centimetres; that painted surfaces be flat and even in coverage and colour and free of obvious bubbles, runs, wrinkles, damage, missed areas and exposed primer, and that the coating adhesion result after the test of 6.23.2 be not greater than 0.30; that decorative plastic parts be flat, smooth and even in colour and free of cracks, bubbles and obvious sink marks and that they resist ageing; that the components be firmly and reliably mounted and the compressor provided with anti-vibration measures; that the harmful substance content of the hardware of the control system comply with GB/T 26572; that by agreement between manufacturer and user the unit should be provided with alarm interfaces for smoke and water leakage and interlocking interfaces for other safety devices, and should be fitted with anti-vibration mountings, the pipework between indoor and outdoor units having anti-vibration measures; that the accuracy of the temperature and humidity sensors be plus or minus 1 °C over the range 17 °C to 40 °C and plus or minus 10% over the relative humidity range 30% to 80%; that for a unit with a back-up cold source the performance corresponding to each kind of cold source meet the document; and that the electrical equipment work normally below an altitude of 1000 m, additional measures being agreed with the user above that altitude. For indirect evaporative cooling units the technical requirements, test methods, inspection rules, marking, packaging, transport and storage follow JB/T 14641 or JB/T 14643.

5.2 As to safety, the design of compressor refrigeration and composite refrigeration units is to comply with GB 25130 and GB/T 9237. Air filters and heat-insulating and sound-absorbing materials are to meet the class B1 flame-retardant requirement of GB 8624-2012. The structure and enclosure are to give sufficient protection against inadvertent contact with live parts, including after removable parts have been taken off in normal use, and the test probe of 6.4.1 is not to touch a live part; moving parts are to be placed or covered so as to give sufficient protection against injury in normal use, their guards being non-removable and mechanically strong enough, and the test probe of 6.4.2 is not to touch a hazardous moving part nor is the guard to suffer any effect on other performance. The waterproof rating of the outdoor part is to be not lower than its declared value and at least IPX4 of GB/T 4208. The cold insulation resistance is to be not less than 2 megohms. The leakage current is not to exceed 2 mA per kilowatt with a maximum of 30 mA, calculated from the rated power input for units of nominal cooling capacity not greater than 24.36 kW and from the declared nominal cooling power input for units above that capacity. No breakdown or flashover is to occur during the electric strength test. The unit is to have a permanent and reliable protective earthing device to which the accessible metal parts are reliably connected, its earthing terminal and clamping device serving no other purpose, the parts of the protective earthing circuit being of sufficiently corrosion-resistant metal and the circuit marked as required by 8.2 of GB/T 5226.1-2019; the protective earthing circuit is to be continuous, the maximum voltage drop measured by the method of 6.4.7 b) not exceeding Table 8, which for minimum effective cross-sectional areas of the branch conductor of 1.0, 1.5, 2.5, 4.0 and above 6 square millimetres allows 3.3, 2.6, 1.9, 1.4 and 1.0 V respectively at a test current of 10 A; and for units of nominal cooling capacity not greater than 24.36 kW, or where the test equipment can supply 1.5 times the rated current, the earth resistance measured according to 27.5 of GB 4706.1-2005 is not to exceed 0.1 ohm.

5.3 As to electromagnetic compatibility, the terminal disturbance voltage, disturbance power and discontinuous interference of units of nominal cooling capacity not greater than 24.36 kW are not to exceed the limits of GB 4343.1, and those of larger units are to meet the corresponding standard or the agreement between the parties. The harmonic current of units whose input current per phase is not greater than 16 A is not to exceed the limits of GB 17625.1, and that of units above 16 A is to meet the corresponding standard or the agreement. The electrical control system is to meet the class II immunity requirements of GB/T 4343.2.

5.4 to 5.6 No part of the refrigerating system is to leak refrigerant. The water or glycol system is to be strong enough that no abnormal deformation or leakage appears at the pipework, components or joints throughout the pressure test. The unit is to start normally on trial running and to run without abnormality.

5.7.1 and 5.7.2 The measured nominal cooling capacity is to be not less than 95% of the declared value for compressor refrigeration and chilled-water units, and, for composite refrigeration units, not less than 95% of the declared value for the corresponding mode in compressor refrigeration mode and in free cooling mode II, and not less than 55% of the declared cooling capacity of the compressor refrigeration mode in free cooling mode I. The measured nominal cooling power input is not to exceed 110% of the declared value, or of the declared value for the corresponding mode.

5.7.3 The measured nominal cooling energy efficiency ratio is to be not lower than 95% of the declared value and not lower than the limits of Table 9 for compressor refrigeration units, and not lower than 95% of the declared value and not lower than the limits of Table 11 for chilled-water units; for composite refrigeration units it is to be not lower than 95% of the declared value and not lower than the limits of Table 9 or Table 10 in compressor refrigeration mode, and not lower than 95% of the declared value for the corresponding mode in free cooling modes I and II. Table 9, which covers compressor refrigeration units and heat pipe composite units, sets an EER of 3.20 for the standard return air temperature type and 2.70 for the low return air temperature type of the air-cooled form, 3.60 and 3.20 for the water-cooled form and 3.45 and 2.90 for the evaporatively cooled form. Table 10 sets 3.20 and 2.80 for the glycol economic cooler composite form. Table 11 sets the nominal cooling energy efficiency coefficient limits for chilled-water units by form, coil type or water-cooled heat pipe type, by position relative to the servers, room level, in-row or rack level, and by return air temperature type; in the extracted text the twelve values of that table run together and are therefore not reproduced here. A note adds that where the declared nominal cooling capacity was designed for other conditions, only the deviation from the declared value is checked.

5.7.4 and 5.7.5 At the nominal cooling condition the measured sensible heat ratio is to be not less than 0.90 for the low return air temperature type and not less than 0.95 for the standard return air temperature type, and the measured cold-air ratio not more than 4.0 W per cubic metre per hour for the low return air temperature type and not more than 5.0 for the standard return air temperature type. For composite refrigeration units both are checked in compressor refrigeration mode and in free cooling mode II. In each clause a note states that where the declared nominal cooling capacity was designed for other conditions, the sensible heat ratio and the cold-air ratio are checked against the declared value.

5.8 At the annual energy efficiency conditions of Table 6 or Table 7 and at a load ratio of 100%, the measured annual energy efficiency ratio is to be not less than Tables 12, 13 or 14 and not less than 95% of the declared value; at standard or non-standard annual energy efficiency conditions and the corresponding part load ratio, it is to be not less than 95% of the declared value. A note explains that a load ratio of 100% means full load operation of the compressor for a fixed capacity unit and a load ratio of 100% for a variable capacity unit. Table 12, for fixed capacity compressor refrigeration units, sets an AEER of 4.60 for the standard and 4.00 for the low return air temperature type of the air-cooled form, 4.80 and 4.20 for the water-cooled form and 4.70 and 4.10 for the evaporatively cooled form. Table 13, for variable capacity units, sets 4.90 and 4.30, 5.10 and 4.50, and 5.00 and 4.40 for the same three forms. Table 14 sets 6.40 and 4.90 both for the heat pipe composite form and for the glycol economic cooler composite form.

5.9 to 5.12 At the maximum load cooling condition of Table 2, 4 or 5 the unit is to run normally and continuously without damage to any component and without the overload protector tripping; at the low temperature cooling condition it is to start normally, no safety device is to trip during operation and no frost or ice is to form on the surface of the evaporator; at the nominal cooling condition of Table 2, 4 or 5 in the minimum load test it is to start and run normally and continuously without damage to any component and without the overload protector tripping; and at the condensation condition of Table 2, 3, 4 or 5 no condensate is to overflow or be blown out anywhere but at the drain, no water is to drip from the outer surface or the air outlet, and the indoor supply air is to carry no droplets.

5.13 to 5.15 For a unit with a humidification function the measured humidification capacity is to be not less than 95% of the declared value, the declared value being given to one decimal place. For a unit with a reheating function the measured reheating capacity is to be not less than 95% and not more than 110% of the declared value. At the nominal cooling condition the water pressure drop of a water-cooled unit and that of a chilled-water unit are each not to exceed 100 kPa and not to exceed 110% of the declared pressure drop, while a glycol solution pressure drop is not to exceed 150 kPa and 110% of the declared value; a note states that where the declared nominal cooling capacity was designed for other conditions, the water resistance is checked against the declared value.

5.16 At the nominal cooling condition the measured noise, as sound pressure level, is not to exceed the limits of Tables 15 and 16 and is not to exceed the declared value by more than 3 dB(A), Table 15 applying to compressor refrigeration and composite refrigeration units and Table 16 to chilled-water units; for composite refrigeration units the noise is checked in compressor refrigeration mode and in free cooling mode II. Table 15 gives, in dB(A) for the room level unit of nominal cooling capacity not greater than 50000 W and above 50000 W, for the in-row unit in the same two capacity ranges and for the rack level unit, indoor side limits of 74, 77, 78, 81 and 73 and outdoor side limits of 67, 69, 69, 71 and 68. Table 16 gives indoor side limits of 72, 75, 78, 79 and 70 for the same five columns, and sets no outdoor side limit.

5.17 to 5.20 The class of the air filter is to be not lower than class C4 of GB/T 14295-2019. A composite refrigeration unit is to switch automatically between its working modes and to run normally after switching. The control requirements are that the unit work normally within plus or minus 10% of rated voltage and plus or minus 2 Hz of rated frequency, that it have a power failure alarm, that it restart of itself when supply is restored, that it keep the parameter settings and the operating state it had before the failure, and that it have a delayed start function; that it should have a display screen able to show parameters such as temperature and humidity and the operating state of components such as valves, fans and compressors, and that it be able to display and store fault and alarm records; that it display an alarm when an alarm or protection is triggered and act according to the preset control logic, the alarms provided including at least, for compressor refrigeration and composite refrigeration units, power failure, high and low pressure of the refrigerating system, compressor fault, air pressure, fan fault, electric heater fault where fitted and humidifier fault where fitted, and, for chilled-water units, power failure, air pressure, fan fault, electric heater fault and humidifier fault where fitted; and that it be able, through a communication interface, to read the monitored analogue parameters, the working mode and the operating state remotely, to issue particular on and off commands remotely and to set parameters such as working mode, operating state and return and supply air parameters remotely, the values and states read remotely agreeing in each case with those shown on the display screen or controller. The drift rate of an evaporatively cooled unit is not to exceed 0.01%.

6 Test methods

6.1 The test room is to be large enough for the unit to be installed as required, and the air speed near the unit during the test is not to exceed 2.5 m/s. The supply is to provide the rated voltage and frequency of the unit with a frequency deviation of not more than plus or minus 0.5 Hz and a voltage deviation of not more than plus or minus 5%; the cooling water quality is to comply with GB/T 29044; and for a unit with an electrode humidifier the conductivity of the water used in the humidification test is to be adjusted to 300 microsiemens per centimetre to 315 microsiemens per centimetre. The type and accuracy of the instruments are to comply with GB/T 17758 and the instruments to be verified or calibrated and within their period of validity. The measurement of dry-bulb and wet-bulb temperatures on the air side is to comply with GB/T 17758, that of water side pressure loss, temperature and flow with GB/T 10870 and GB/T 18430.1, and the size of the connecting duct and the position of the static pressure measurement with Annex B.

6.2 The unit is to be installed firmly as its instructions or the manufacturer require, charged with the type and quantity of refrigerant marked on the nameplate, the charge not being adjusted during the test. The environmental chambers are to be large enough for air circulation and normal operation under identical conditions, and the air flow handled by the conditioning plant on the outdoor and indoor sides is to be not less than that of the unit under test, the air being returned to the test room at low speed and evenly after treatment to the required conditions. The distance between the chamber wall and the side of the outdoor unit from which air is discharged is to be not less than 1.8 m, that between the other surfaces of the unit and the chamber wall not less than 0.9 m, and that between outdoor units where several are fitted not less than 0.9 m. The unit is to be supplied at its declared rated voltage and frequency.

6.3 The tolerances on the operating conditions during the test and the acquisition and processing of the data are to comply with GB/T 17758.

6.4 The safety tests are carried out as follows. For protection against electric shock, the type B test probe of GB/T 16842-2016 is pushed through the openings to any permitted depth with an inconspicuous force and turned or bent before, during and after insertion in each position in an attempt to touch live parts; where the probe cannot enter an opening, a force of 20 N is applied perpendicularly, and if the probe then enters, the test is repeated with the probe at an angle. For protection against moving parts, a spring hammer is used according to GB/T 2423.55 to strike each possible weak point of the guard three times with an impact energy of 0.5 J, and a probe similar to the type B probe of GB/T 16842-2016 is then applied with a force not exceeding 5 N in an attempt to touch hazardous moving parts, a note stating that this probe has a circular stop face 50 mm in diameter in place of the original non-circular one. The outdoor unit is given the water test of GB/T 4208 for the appropriate degree of protection, immediately after which the leakage current and electric strength tests are carried out. The insulation resistance between live parts and accessible metal parts is measured with an insulation resistance meter of 500 V rated voltage. For the leakage current test the unit is at room temperature and disconnected from the supply, an alternating voltage of 1.06 times the rated voltage for a single-phase unit, or of 1.06 times the rated voltage divided by the square root of three for a three-phase unit, is applied between the live parts and the accessible metal parts, and the leakage current is measured within 5 s of the voltage being applied. For the electric strength test a substantially sinusoidal voltage at 50 Hz or 60 Hz of 1000 V plus twice the rated voltage is applied between the live parts and the accessible metal parts for 1 min, or 1.2 times that value for 1 s; a note exempts electronic components used in control circuits whose voltage to earth is below 30 V alternating, as an effective value, or direct. The protective earthing device is judged by visual inspection and manual test, and the continuity of the protective earthing circuit is tested with a current drawn from a source whose open circuit voltage does not exceed 12 V, alternating or direct, passed in turn between the earthing terminal and each accessible metal part.

6.5 The electromagnetic compatibility tests follow GB 4343.1 for units of nominal cooling capacity not greater than 24.36 kW and the corresponding standard or the agreement between the parties for larger units; the harmonic current test follows GB 17625.1 for units whose input current per phase is not greater than 16 A and the corresponding standard or the agreement for larger currents; and the immunity test follows GB/T 4343.2.

6.6 The tightness test is made at the refrigerant charge marked on the nameplate, with a refrigerant leak detector of 1 by 10 to the power minus six Pa cubic metre per second sensitivity for units of nominal cooling capacity of 28000 W and below and of 1 by 10 to the power minus five Pa cubic metre per second for units above 28000 W.

6.7 For the strength test the water or glycol circuit is subjected to a hydraulic test at 1.25 times the design pressure or a pneumatic test at 1.15 times the design pressure, the pressure being held for more than 10 min while the system is examined for deformation, leakage and other abnormality.

6.8 and 6.9 The unit is trial run on power at rated voltage and frequency. The cooling capacity test is made under the stated conditions by the method of GB/T 17758, the cooling power input, air flow and other quantities being measured at the same time and the sensible heat ratio and cold-air ratio calculated from them; for a water-cooled heat pipe unit the heat balance between the two sides is not to differ by more than plus or minus 10%. The cooling power input of an air-cooled unit includes the power of the compressor, the fans, the electrical control equipment, the air-cooled condenser and the other components of the unit. For a water-cooled unit, 3% of the measured cooling capacity is taken as the power of the cooling water circulating pump and the cooling tower fan. The energy efficiency coefficient of a chilled-water unit is calculated by formula (1), whose terms are the cooling capacity supplied in watts, the power of the fans and the control system in watts, the water resistance in pascals, the water flow in cubic metres per second and the pump efficiency, which is taken as 0.65.

6.10 The annual energy efficiency ratio is obtained by the test and calculation methods of Annex C.

6.11 to 6.14 For the maximum load cooling test the unit runs at the condition of Table 2, 4 or 5 until steady, then for 1 h continuously, stops for 3 min and runs again for 1 h. For the low temperature cooling test it starts at the condition of Table 2, 4 or 5 and runs continuously for 4 h after the first 10 min. For the minimum load cooling test the compressor frequency, outdoor fan speed and valve opening are set to give the smallest capacity of the unit, which starts in compressor refrigeration mode at the nominal cooling condition of Table 2, 4 or 5 and runs continuously for 2 h after the first 10 min, the measured part load ratio during the test not exceeding the declared minimum part load ratio by more than 3 percentage points, the base of the calculation being the declared nominal cooling capacity and the test not applying to fixed capacity units. For the condensation test the temperature controller and other controls are set, within what the manufacturer allows, to the state most likely to produce condensate, the drain pan is filled with water up to the drain, and the unit runs at the condensation condition of Table 2, 3, 4 or 5 at rated frequency and voltage until steady and then for 4 h continuously. In each of these tests the compressor frequency and the indoor and outdoor fan settings are kept as they were in the nominal cooling capacity test.

6.15 and 6.16 The humidification capacity test is made at the condition of Table 2, 3, 4 or 5 by the method of Annex D, with the cooling function switched off; the humidification power input is the power of the humidifier itself and does not include the fans or the control components, and the fan setting is that of the nominal cooling capacity test. The reheating capacity test is made at the condition of Table 2, 3, 4 or 5 with the cooling and humidifying functions switched off, the power input being measured once the unit is steady; the reheating capacity includes the power of the reheater, the fan motors and the electrical control equipment, and the fan setting is again that of the nominal cooling capacity test.

6.17 to 6.19 The water or glycol resistance is measured by the method of GB/T 18430.1 during the nominal cooling capacity test. The noise is measured by the method of Annex E. The class of the air filter is tested by the method of GB/T 14295-2019.

6.20 For the mode switching test the unit runs in compressor refrigeration mode at the nominal cooling condition of Table 4 or 5 until steady and then for 20 min; the outdoor side temperature is lowered to the switching temperature set by the manufacturer and the unit is run for 20 min in the second mode once steady, the temperature being lowered further until it switches of itself if it does not, and the outdoor temperature being recorded; the same is done for the third mode and for each further mode in turn until every mode has run for not less than 20 min, the outdoor temperature being recorded each time; and finally the outdoor temperature is raised to the temperature set for switching back to the compressor refrigeration cycle and the unit is run for 20 min once steady, the temperature being raised further until it switches of itself if it does not.

6.21 The control requirement tests are carried out by setting the input voltage and frequency to the upper and lower limits of 5.19.1 and checking that the unit starts and runs normally; by disconnecting any one phase and checking for an alarm; by running the unit normally for 10 min, disconnecting the supply, restoring it after 1 min and checking that the unit starts of itself; by the same sequence, checking that the set temperature and other parameters after the self start agree with those before the failure; and by the same sequence, recording the interval between the restoration of the supply and the start. The display and storage functions are checked by running the unit normally for 10 min and looking at the display screen or controller for the operating state, and by simulating the alarm functions the unit has and checking that the corresponding records have been stored. The alarm and protection functions are checked by simulating each alarm in turn and looking for the alarm display and the corresponding protective action. The remote control functions are checked by connecting the communication of the unit to a remote monitoring station and comparing the parameters, working mode, operating state and the response to on and off commands and to parameter changes made at the station with what the display screen or controller shows.

6.22 and 6.23 The drift rate test follows the method of JB/T 11530. The salt spray test of the electroplated parts follows GB/T 2423.17 for a test period of 24 h, the surface being cleaned and degreased before the test and rinsed free of residual salt with clean water before the corrosion is examined. For the coating adhesion test an area of 10 mm by 10 mm is taken anywhere on the outer surface of a painted part and eleven parallel cuts 1 mm apart and reaching the base material are made with a new blade in each of the two directions; medical zinc oxide adhesive tape is stuck firmly over the cut area and pulled off quickly along the direction of one set of cuts, the number of squares from which the paint film has come away is counted, a square retaining less than 70% of its film counting as detached, and the adhesion is rated as the ratio of that number to 100. The harmful substance content of the hardware of the control system is tested according to GB/T 26572.

7 Inspection rules

7.1 The inspection of the unit is divided into works inspection, sampling inspection and type inspection, the items, technical requirements and test methods being given in Table 17. Table 17 lists twenty-seven items, namely the general requirements, safety requirements, electromagnetic compatibility, tightness, strength, running, nominal condition performance, annual energy efficiency, maximum load cooling, low temperature cooling, minimum load cooling, condensation, humidification capacity, reheating capacity, water resistance, noise, air filtration performance, mode switching, protection requirements, insulation resistance, leakage current, electric strength, earthing device, the four control requirement items of power supply adaptability, display and storage, alarm and protection and remote control, and drift rate, with the clause of the technical requirement and of the test method for each and a mark showing which of the three inspections it belongs to; in the extracted text those marks cannot be matched to their rows with confidence and are therefore not reported. Six footnotes state that the strength and water resistance items do not apply to units without a water or glycol system, that the items marked accordingly do not apply to chilled-water units, that the minimum load cooling test does not apply to fixed capacity units, that the humidification and reheating items apply where an electric heater or a humidifier is fitted, that the drift rate applies to evaporatively cooled units, and that the test method for the sensible heat annual energy efficiency is given in Annex F.

7.2 to 7.4 Every unit is to pass the inspection of the quality inspection department of the manufacturer before it leaves the works. The quality control measures of the manufacturer are to include sampling inspection, particularly for units made in quantity, but the sampling plan, inspection level and acceptable quality level may be settled by the manufacturer. Type inspection is to be carried out at least once every four years, and the first unit is to undergo the type test when a new product is developed or an established product substantially improved, when a wholly new production line is used, and when a production line is moved or substantially altered.

8 Marking, packaging, transport and storage

8.1 Every unit is to carry a permanent nameplate in a conspicuous position, complying with GB/T 13306 and containing the items of Table 18. Table 18 lists nineteen items with their units and, for each of the compressor refrigeration, chilled-water and composite refrigeration types, whether the item is to be marked: the name and model of the product, the name and trademark of the manufacturer, the works number, the year and month of manufacture, the refrigerant number, the rated refrigerant charge in kilograms, the rated voltage, number of phases and frequency, the maximum running current in amperes, the nominal cooling capacity and the nominal cooling power input in kilowatts, the nominal cooling energy efficiency ratio and the energy efficiency coefficient in kilowatts per kilowatt, the humidification capacity in kilograms per hour, the reheating capacity in kilowatts, the annual energy efficiency ratio in kilowatts per kilowatt, the return air temperature type or condition, the noise as sound pressure level in dB(A), the mass in kilograms and the volume concentration of the glycol solution as a percentage. In the extracted text the marking requirements cannot be matched to their rows with confidence and are therefore not reported. The notes state that the performance parameters marked on the nameplate are those at the nominal conditions of Table 2, 3, 4 or 5; that the maximum running current is the highest current the unit is allowed to reach at all the standard conditions and at all the conditions of use the manufacturer allows; that for a heat pipe composite unit the parameters include those of the compressor refrigeration mode and of free cooling modes I and II, and for a glycol economic cooler composite unit those of the compressor refrigeration mode and the free cooling mode; that the humidification capacity is marked where the humidifier is fitted at the works; and that the glycol concentration applies to glycol economic cooler composite units.

8.1.2 to 8.1.5 Where the performance at non-standard conditions is to be declared, it is to be shown with the conditions in the appropriate place, such as the nameplate or the instructions. Where a flammable refrigerant is used, the warning sign numbered 2-2 in Table 2 of GB 2894-2008 is to be marked permanently in a conspicuous position in the colour and form given there, the vertical height of the symbol being not less than 30 mm. The unit is to carry markings showing the operating state, such as the direction of rotation of the fans, the direction of water flow and the state of the indicating instruments and control buttons, and is to bear the number of the document in an appropriate place such as the nameplate.

8.2 Before packing, the unit is to be cleaned, its parts left clean and dry and the parts liable to rust coated with a rust preventive. A unit of nominal cooling capacity below 28000 W should be charged with the rated quantity of refrigerant before packing, and a unit of 28000 W or above may be charged either with the rated quantity of refrigerant or with dry nitrogen at a pressure controlled within 0.02 MPa to 0.1 MPa. The unit is to be wrapped in a plastic bag or damp-proof paper and fixed inside the case so as to avoid damp and mechanical damage in transit. The case is to bear the name of the manufacturer, the model and name of the product, the net and gross mass, the overall dimensions and the handle with care, this way up, keep dry and stacking layer markings, the packaging and storage and transport markings complying with GB/T 6388 and GB/T 191. Every unit is to be delivered with a certificate of conformity giving the model and name of the product, the works number, the signature or stamp of the inspector and the date of inspection; with an instruction manual giving the model and name of the product, the ambient temperature conditions of use and the number of the document, the structural diagram, the refrigerating system diagram and the wiring diagram, the spare parts list and the drawings of the necessary wearing parts, the overall dimensions and the installation instructions, with the installation requirements of GB/T 9237 where a flammable refrigerant is used, and the operating, maintenance and servicing instructions, with the requirements of GB/T 9237 and of Annex DD of GB 4706.32-2012 where a flammable refrigerant is used; and with a packing list.

8.3 The unit is not to be knocked, tilted or exposed to rain or snow during transport and storage, and is to be stored in a dry, well ventilated place.

C Annex C (normative) Test method for the annual energy efficiency of computer room air conditioners

C.1 and C.2 The test conditions are the standard conditions of Table 6 or Table 7 or the conditions declared by the manufacturer. In the annual and part load annual energy efficiency tests the measured air flow at conditions B, C, D and E is not to differ from that at condition A by more than plus or minus 5%, the deviation being calculated by formula (C.1) from the air flow at condition A and at the other conditions; the load ratio for the part load test is agreed with the customer; the measured cooling capacity at conditions B, C, D and E is to be not less than that at condition A; the unit may switch its free cooling function on at conditions B, C, D and E according to its control logic; the external static pressure at those conditions is to be the same as at condition A; and for a unit with a free cooling function the operating mode at conditions B, C, D and E is to be recorded.

C.3 The temperature distribution coefficients of the typical cities of the country are given in Table C.1, which divides the year into five temperature ranges: Ta for 30 °C and above, Tb for 20 °C and above but below 30 °C, Tc for 10 °C and above but below 20 °C, Td for 0 °C and above but below 10 °C, and Te for below 0 °C. In the extracted text the city names and the percentages of that table are destacked and cannot be matched to one another, so the coefficients are not reproduced here. The document takes Beijing as the typical city and uses the temperature distribution coefficients of Beijing to assess the annual and part load annual energy efficiency ratios of every unit; where necessary, a typical city suited to the region in which the unit is to be used may be chosen instead. A note states that the data come from the special meteorological data set for the analysis of building thermal environments in China, which is based on the measured meteorological data of 270 surface stations over the 33 years from 1971 to 2003.

C.4 The annual energy efficiency ratio is calculated by formula (C.2) and the part load annual energy efficiency ratio by formula (C.3), both as the reciprocal of the sum, over the five conditions A to E, of the temperature distribution coefficient of the condition divided by the energy efficiency ratio, or the part load energy efficiency ratio, measured at that condition. The results are expressed in watt hours per watt hour.

D Annex D (normative) Test method for the humidification capacity of computer room air conditioners

D.1 and D.2 The test conditions are the standard conditions of Table 2, 3, 4 or 5 or the conditions declared by the manufacturer. The air circuit and refrigerant pipework of the unit are arranged and installed as in the nominal cooling capacity test, the unit controls the humidifier automatically, the water temperature in the pressurised tank is held at 20 °C plus or minus 5 °C and the tank pressure is as the manufacturer specifies, and the pipe from the tank to the humidifying cylinder is insulated so that the water temperature in the tank and the pipe does not rise above 25 °C during the test.

D.3 The measuring rig is shown in Figure D.1, and the humidification power input is measured with an integrating power meter.

D.4 In the preliminary test the rig is connected as in Figure D.1, the conditions are adjusted to the humidification test condition of Table 2, 3, 4 or 5, the humidifying cylinder is filled before the unit starts, the unit is set to the humidification mode and started, and it runs continuously for not less than 40 min while the make-up and drain water are watched. The preliminary test ends immediately after the cylinder has been refilled, and the formal test then begins, the masses of the pressurised tank and of the drain tank being read and recorded at that moment. The unit runs continuously for not less than 40 min and over at least four humidification cycles, the masses of the two tanks after each refill and the duration of each cycle being recorded, and the variation of the humidification capacity, calculated by formula (D.1) from the make-up water of the first cycle and that of the second to fourth cycles, is to lie within plus or minus 5%, the test being repeated if it does not; a note allows the cycles to be divided equally into four when their number is a multiple of four. The test ends immediately after a refill of the cylinder, the unit stops, and the masses of the two tanks are read again. A complete humidification cycle runs from one refill of the cylinder to the end of the next. The humidification power input includes the power of the humidifying system itself, the fans and the control components.

D.4.3 The humidification capacity is calculated by formula (D.2) as the difference between the make-up water of the humidifying cylinder and the drain water, obtained from the four tank masses and converted to an hourly rate by the humidification time in minutes. It is expressed in kilograms per hour.

E Annex E (normative) Test method for the noise of computer room air conditioners

E.1 to E.3 The test room and the measuring instruments are to comply with GB/T 17758. The unit is connected to all its auxiliary parts, including the filter and the factory-made pipework and fittings, as the manufacturer requires for installation, and installed in the test room. During the noise test the conditions are held at the nominal cooling condition and the measurement is made after 30 min of running at rated voltage and frequency, the operating state, including fan speed and compressor speed, being that of the nominal cooling capacity test; for a composite refrigeration unit the noise is measured in compressor refrigeration mode and in free cooling mode II separately. A unit whose external static pressure in the nominal cooling capacity test exceeded 0 Pa is fitted with a duct for the noise test, the static pressure tapping being placed according to Annex B, and its discharge air is led out of the test room so that it does not affect the measurement. For a room level unit the duct dimensions follow Annex B where the air is led out through an air flow measuring device, and where it is led out through a duct the discharge of the unit is connected to a damping duct more than 2 m long fitted with a discharge damper for adjusting the external static pressure. For a rack level unit a duct of the dimensions of Annex B is connected to the discharge, the duct is disconnected from the air flow measuring device, both unit and duct standing in the noise test room, and a discharge damper is fitted to the duct to adjust the static pressure. A unit whose external static pressure was 0 Pa is tested without a duct.

E.4 For a single outdoor unit of the upflow kind the measuring points lie 1 m from the unit at the centre of each of its four sides, at a height equal to half the sum of the height of the outdoor unit and 1 m, giving four points as in Figure E.1; for the horizontal flow kind they lie 1 m from the discharge face and the two side faces at their centres, at the same height, giving three points as in Figure E.2. Where several outdoor units form the smallest unit able to run, they are set with their discharge in the same direction and, for the upflow kind, spaced 1.5 m plus or minus 0.1 m apart, the points lying 1 m from the reference plane at the centre of each of the four sides and at a height equal to half the sum of the reference height and 1 m, giving four points as in Figure E.3, and for the horizontal flow kind three points at the discharge face and the two side faces as in Figure E.4. Notes define the smallest unit as the fewest outdoor units needed for the air conditioner to run normally, and state that where the outdoor units differ in length, width or height, the surfaces of the longest and widest of them serve as the reference plane and reference height.

E.4.2 For an indoor unit tested with a duct, the points for the upflow kind lie 1 m from the unit at the centre of each of its four sides at a height equal to half the sum of the height of the indoor unit and 1 m, giving four points as in Figure E.5; the horizontal flow kind is measured in the same way as in Figure E.6, but where a point coincides with the duct it is moved 0.15 m to either side of the duct, giving five points in all as in Figure E.7; and the downflow kind is measured in the same way, giving four points as in Figure E.8. A direct-blow unit is measured at the four points of the upflow arrangement.

E.5 Under the stated installation and operating conditions the A-weighted sound pressure level is measured at each specified point with the sound level meter set to slow, the value being taken as the mean of the observed maximum and minimum; where those differ by more than 3 dB, a sound pressure level system with a recording function is used and the mean of 60 s of acquisition is taken. Where the air speed at a point exceeds 1 m/s the probe is fitted with a windshield. The noise of the unit is the A-weighted mean sound pressure level of the specified points. For a free field over one reflecting plane, that is a semi-anechoic room, it is calculated by formula (E.1) from the levels at the individual points and the background noise correction; for an approximate free field over one reflecting plane it is calculated by formula (E.4), which adds an environmental noise correction. The background noise correction is obtained from formula (E.2) and the difference between the time-averaged level measured with the unit running and the time-averaged background level from formula (E.3). The legend gives the mean sound pressure level of the unit, the level at the i-th specified position, the background noise correction, the total number of points, the difference between the measured and the background level, the two time-averaged levels, the environmental noise correction, the area of the measurement surface, the A-weighted mean sound absorption coefficient of Table A.1 of GB/T 3767-2016 and the total area of the boundary surfaces of the test room, walls, ceiling and floor, all levels being in decibels and the areas in square metres. A note states that where the difference between the measured and the background level is more than 6 dB and not more than 15 dB the background correction of formula (E.2) is applied, and that where it exceeds 15 dB the correction is zero and no background correction is needed.