4 Rating capacity test 4.1 Basic principles method of calculation for the determination of capacities 4.1.1 Heating capacity The heating capacity of air conditioners and of air-to-air
Basic principles method of calculation for the determination of capacities
The heating capacity of air conditioners and air-to-air or water-to-air heat pumps is determined through measurements conducted in a calorimeter room or by utilizing the air enthalpy method.
The heating capacity of air conditioners and air-to-air heat pumps with a cooling capacity of 12 kW or less must be assessed through measurements conducted in a calorimeter room.
The heating capacity of air-to-water and water-to-water heat pumps, as well as liquid chilling packages, is calculated using the direct method at the water or brine heat exchanger This involves measuring the volume flow of the heat transfer medium along with the inlet and outlet temperatures, while also accounting for the specific heat capacity and density of the medium.
For steady state operation, the heating capacity shall be determined using the following formula:
The heat capacity, denoted as \$P_H\$, is measured in Watts, while the volume flow rate, represented by \$q\$, is quantified in cubic meters per second Additionally, the density, symbolized by \$\rho\$, is expressed in kilograms per cubic meter, and the specific heat at constant pressure, indicated as \$c_p\$, is measured in joules per kilogram per Kelvin.
∆ t is the difference between inlet and outlet temperatures, expressed in Kelvin
NOTE 1 The mass flow rate can be determined directly instead of the term (q x ρ)
NOTE 2 The enthalpy change ∆H can be directly measured instead of the term (cp x ∆t)
For the heating capacity calculation in transient operation, refer to 4.5.3.2
The heating capacity must be adjusted to account for the heat generated by the fan or pump If the fan or pump is an integral component of the indoor heat exchanger, the power calculated in sections 4.1.5.2 or 4.1.6.3, which is excluded from the total power input, should also be deducted from the heating capacity Conversely, if the fan or pump is not an integral part of the unit, the power calculated in sections 4.1.5.3 or 4.1.6.4, which is included in the effective power input, should be added to the heating capacity.
The cooling capacity of air conditioners and air-to-air or water-to-air heat pumps is assessed through measurements in a calorimeter room or by utilizing the air enthalpy method.
The cooling capacity of air conditioners and air-to-air heat pumps with a capacity of 12 kW or less must be assessed through measurements conducted in a calorimeter room.
The cooling capacity of air-to-water and water-to-water heat pumps, as well as liquid chilling packages, is calculated using the direct method at the heat exchanger This involves measuring the volume flow of the heat transfer medium and the inlet and outlet temperatures, while accounting for the specific heat capacity and density of the medium.
The cooling capacity shall be determined using the following formula: p
The cooling capacity (P C) is measured in watts and is determined by the volume flow rate (q) in cubic meters per second, the density (ρ) in kilograms per cubic meter, and the specific heat at constant pressure (c p) in joules per kilogram per Kelvin.
∆ t is the difference between inlet and outlet temperatures, expressed in Kelvin
NOTE 1 The mass flow rate can be determined directly instead of the term (q x ρ)
NOTE 2 The enthalpy change ∆H can be directly measured instead of the term (c p x ∆t)
The cooling capacity must be adjusted to account for the heat generated by the fan or pump If the fan or pump is an integral component of the unit, the power calculated in sections 4.1.5.2 or 4.1.6.3, which is excluded from the total power input, should be added to the cooling capacity Conversely, if the fan or pump is not an integral part of the unit, the power calculated in sections 4.1.5.3 or 4.1.6.4, which is included in the effective power input, should be subtracted from the cooling capacity.
The heat recovery efficiency of air-to-water and water-to-water heat pumps, as well as liquid chilling packages, is assessed using the direct method at the water or brine heat exchanger This involves measuring the volume flow of the heat transfer medium along with its inlet and outlet temperatures, while accounting for the specific heat capacity and density of the medium.
The heat recovery capacity shall be determined using the following formula: t c q
The heat recovery capacity, denoted as P HR, is measured in Watts It is influenced by the volume flow rate (q), which is expressed in cubic metres per second, and the density (ρ), measured in kilograms per cubic metre Additionally, the specific heat at constant pressure (c p) is quantified in joules per kilogram and Kelvin.
∆ t is the difference between inlet and outlet temperatures expressed in Kelvin
NOTE The mass flow rate can be determined directly instead of the term (q x ρ) The enthalpy change ∆ H can be directly measured instead of the term (c p x ∆ t )
The heat recovery capacity must be adjusted based on the pump's role in the system If the pump is an integral component of the heat recovery exchanger, the power calculated in section 4.1.6.3 should be subtracted from the heat recovery capacity Conversely, if the pump is not an integral part of the unit, the power calculated in section 4.1.6.4 should be added to the heat recovery capacity.
4.1.4 Power input of fans for units without duct connection
For units not designed for duct connection and lacking the ability to handle external pressure differences, the power consumed by the integral fan must be considered part of the unit's effective power consumption.
4.1.5 Power input of fans for units with duct connection
4.1.5.1 The following corrections of the power input of fans shall be made to both indoor and outdoor fans, where applicable
When a fan is a key component of a unit, only a portion of the fan motor's input power is considered in the effective power consumption of the unit The specific fraction to be excluded from the total power absorbed by the unit can be determined using the formula: \$\eta\$.
Test apparatus
4.2.1 Arrangement of the test apparatus
The test apparatus must be designed to meet all requirements for adjusting set values, stability criteria, and measurement uncertainties as specified by this European Standard.
4.2.1.2 Test room for the air side
To ensure optimal testing conditions, the test room must be sized to prevent any airflow resistance at the air inlet and outlet orifices of the test object Airflow should not create a short circuit between these orifices, with velocities not exceeding 1.5 m/s when the test object is off Additionally, the air velocity in the room must not surpass the average velocity through the unit inlet Unless specified otherwise by the manufacturer, the air inlet and outlet orifices should be positioned at least 1 meter away from the test room surfaces.
Any direct heat radiation by heating units in the test room onto the unit or onto the temperature measuring points shall be avoided
To ensure accurate measurements, the connections of a ducted air unit to the test facility must be airtight, preventing significant air exchange with the surrounding environment.
For appliances with integral and adjustable water or brine pumps, the external static pressure shall be set at the same time as the temperature difference
When the liquid pump has one or several fixed speeds, the speed of the pump shall be set in order to provide the minimum external static pressure
In case of variable speed liquid pump, the manufacturer shall provide information to set the pump in order to reach a maximal external static pressure of 10 kPa
4.2.1.5 Liquid chilling package for use with remote condenser
Units for use with remote condenser are tested by using a water-cooled condenser, the characteristics of which shall enable the intended operating conditions to be achieved
4.2.2 Installation and connection of the test object
The test object must be installed and connected according to the manufacturer's installation and operation manual Accessories offered as options are not part of the test Additionally, if a backup heater is included, it should be turned off or disconnected to ensure it does not affect the testing process.
For single ducts, it is essential to keep the discharge duct as short and straight as possible, adhering to the manufacturer's guidelines The minimum distance between the unit and the wall for proper air intake should not be less than 50 cm Additionally, no accessories should be attached to the discharge end of the duct.
For double duct units, identical specifications are necessary for both suction and discharge ducts, except when the unit is intended for direct wall installation In the case of multisplit systems, testing should be conducted with the system functioning at a capacity ratio of 1, or as near to that ratio as feasible.
To optimize performance, set the highest temperature on the control device during heating mode and the lowest temperature during cooling mode Always refer to the manufacturer's instructions for the recommended temperature settings based on specific rating conditions.
For units equipped with open-type compressors, the manufacturer will provide or specify the electric motor The compressor must operate at the rotational speed designated by the manufacturer.
For inverter type control units, frequency settings must be established for each specific rating condition The manufacturer is responsible for supplying documentation that details how to gather the necessary data for configuring the required frequencies.
For the successful initiation of the system, it is essential that a knowledgeable technician familiar with control software is present Therefore, the manufacturer or their designated representative should be on-site during the installation and testing preparations.
4.2.2.2 Installation of unit consisting of several parts
For the installation of a multi-part unit, it is essential to follow specific conditions: a) refrigerant lines must adhere to the manufacturer's guidelines, with a standard length of 5 m, extendable to a maximum of 7.5 m if necessary; b) the elevation difference between lines should not exceed 2.5 m; c) thermal insulation must be applied as per the manufacturer's instructions; and d) unless design constraints apply, at least 50% of the connecting lines should be exposed to outdoor conditions, while the remainder should be exposed to indoor conditions.
4.2.2.3 Indoor units of multisplit systems
When testing a multisplit system in a calorimeter room, the air flow rate and the external static pressure shall be adjusted separately for each one of the ducted indoor units
When testing a multisplit system using the air enthalpy method, the air flow rate and the external static pressure shall be adjusted separately for each indoor unit, ducted or not
In case of equipment with non ducted indoor units tested using the air enthalpy method, the above requirement on ducted indoor units shall apply
Temperature and pressure measuring points shall be arranged in order to obtain mean significant values For free air intake temperature measurements, it is required:
To ensure effective monitoring, it is essential to have a minimum of one sensor per square meter, with at least four measuring points Additionally, the total number of sensors should be limited to 20, evenly distributed across the free air surface.
or to use a sampling device It shall be completed by four sensors for checking uniformity if the surface area is greater than 1 m²
Air temperature sensors shall be placed at a maximum distance of 0,25 m from the free air surface
For control cabinet air conditioners, the inlet temperature at the evaporator is measured instead of the temperature inside the control cabinet
For factory-made units that include a heat pump and a storage tank, it is essential to measure the water inlet and outlet temperatures at both the inlet and outlet of the unit.
For water and brine, the density in formulae (1), (2) and (3) shall be determined in the temperature conditions measured near the volume flow measuring device.
Uncertainties of measurement
The uncertainties of measurement shall not exceed the values specified in Table 1
Table 1 — Uncertainties of measurement for indicated values
Measured quantity Unit Uncertainty of measurement
- static pressure difference kPa ± 1 kPa (Δp ≤ 20 kPa) or ± 5 %(Δp > 20 kPa)
- static pressure difference Pa ± 5 Pa (∆ p ≤ 100 Pa) or ± 5 %(∆p > 100 Pa)
- pressure at compressor outlet kPa ± 1 %
The heating or cooling capacities measured on the liquid side must be determined with a maximum uncertainty of 5%, regardless of the individual measurement uncertainties, including those related to fluid properties.
The steady state heating or cooling capacities measured by the calorimeter method will have a maximum uncertainty of 5%, regardless of individual measurement uncertainties, including fluid property uncertainties However, for single duct units, this maximum uncertainty increases to 10% due to air exchange between the two compartments of the calorimeter room.
The heating capacity measured during transient operation, specifically during defrost cycles, must be assessed using the calorimeter method with a maximum uncertainty of 10% This requirement is applicable regardless of the individual measurement uncertainties, including those related to the properties of fluids.
The heating and cooling capacities measured on the air side using the air enthalpy method must be determined with a maximum uncertainty of 10% This requirement is applicable regardless of the individual measurement uncertainties, including those related to the properties of fluids.
Test procedure
The test conditions are given in EN 14511-2
When utilizing liquid heat transfer media other than water, it is essential to assess and incorporate the specific heat capacity and density of these media in the evaluation process.
Table 4 states permissible deviations of the measured values from the test conditions
For non-ducted units, the adjustable settings such as louvers and fan speed shall be set for maximum steady- state air flow
For inverter type control units, it is essential to follow the manufacturer's specified fan speed, which may differ from the maximum speed, for a given rating condition This indicated speed should be utilized on the control device.
4.4.1.3 Units ducted on the indoor heat exchanger
The manufacturer's specifications for volume flow and external static pressure in cooling or heating mode must be based on standard air and a dry heat exchanger Additionally, the volume flow and pressure difference should also adhere to these standard conditions.
If the airflow rate is given by the manufacturer with no atmospheric pressure, temperature and humidity conditions, it shall be considered as given for standard air conditions
The airflow rate given by the manufacturer shall be converted into standard air conditions vi (measured) vi 1,204 q = q ( measured) ρ
The setting of this airflow rate shall be made when the fan only is operating
The manufacturer’s specified rated air flow rate, adjusted to standard air conditions if needed, will be established, and the resulting external static pressure (ESP) will be measured This ESP will also be converted to standard air conditions accordingly.
If the ESP is lower than the minimum value given in Table 2 (or Table 3), the air flow rate is decreased to reach this minimum value
If the ESP is greater than twice the minimum value given in Table 2 (or Table 3), the air low rate is increased to reach twice this minimum value
If the ESP is greater than the minimum value given in Table 2 (or Table 3) but not greater than twice this minimum value, then keep this ESP
The apparatus used for setting the ESP shall be maintained in the same position during all the tests
Table 2 — Pressure requirement for comfort air conditioners
Minimum external static pressure (ESP min ) a b
For equipment tested without an air filter, the minimum external static pressure must be increased by 10 Pa Additionally, if the manufacturer's installation guidelines specify a maximum allowable discharge duct length of less than 1 meter, the unit can be classified as a free delivery unit and tested as a non-ducted indoor unit with an external static pressure of 0 Pa.
Table 3 — Pressure requirement for close control air conditioners
Minimum external static Pressure (ESP min )
For down-flow discharge into double floor For up-flow discharge into duct all units
4.4.1.4 Units ducted on the outdoor heat exchanger
The volume flow and the pressure difference shall be related to standard air and with dry heat exchanger
If the air flow rate is given by the manufacturer with no atmospheric pressure, temperature and humidity conditions, it shall be considered as given for standard air conditions
The air flow rate given by the manufacturer shall be converted into standard air conditions The air flow rate setting shall be made when the fan only is operating
The rated air flow rate given by the manufacturer shall be set and the resulting external static pressure (ESP) measured
If the ESP is lower than 30 Pa, the air flow rate is decrease to reach this minimum value
The apparatus used for setting the ESP shall be maintained in the same position during all the tests
If the manufacturer's installation guidelines specify that the maximum permissible discharge duct length is under 1 meter, the unit qualifies as a free delivery unit and should be evaluated as a non-ducted outdoor unit with an external static pressure (ESP) of 0 Pa.
Table 4 — Permissible deviations from set values
Measured quantity Permissible deviation of the arithmetic mean values from set values
Permissible deviations of each of the individual measured values from set values Liquid
- saturated vapour/bubble point temperature ± 0,5 K ± 1 K
Voltage ± 4 % ± 4 % a For units with outdoor heat exchanger surfaces greater than 5 m², the deviation on the air inlet dry bulb temperature is doubled
When evaluating single duct units, the allowable maximum deviation for the arithmetic mean difference between the indoor dry bulb temperature and the outdoor air temperature is 0.3 K This standard also extends to the difference in wet bulb temperatures.
4.4.2 Output measurement for water (brine)-to-water (brine) and water (brine)-to-air units
This condition is achieved and sustained when all measured quantities remain constant for at least 30 minutes, without altering the set values, in accordance with the tolerances specified in Table 4 While periodic fluctuations from regulation and control devices are allowed, the average of these fluctuations must not exceed the permissible deviations outlined in Table 4.
4.4.2.2 Measurement of heating capacity, cooling capacity and heat recovery capacity
To ensure accurate output measurement, it is essential to continuously record all significant data For recording instruments that function cyclically, the sequence must be modified to guarantee a complete recording at least once every 30 seconds.
The output shall be measured in the steady state condition The duration of measurement shall be not less than 35 min
4.4.3 Output measurement for cooling capacity of air-to-water and air-to-air units
This condition is achieved and sustained when all measured quantities remain constant for at least 1 hour, without altering the set values, in accordance with the tolerances specified in Table 4 Periodic fluctuations in measured quantities due to regulation and control devices are allowed, provided that the average of these fluctuations does not exceed the permissible deviations outlined in Table 4.
To ensure accurate output measurement, it is essential to continuously record all relevant data For recording instruments that function cyclically, the sequence must be modified to guarantee a complete recording at least once every 30 seconds.
The output shall be measured in the steady state condition The duration of measurement shall not be less than 35 min
4.4.4 Output measurement for heating capacity of air-to-air units with the air enthalpy method and of air-to-water units
The test procedure includes three distinct phases: a preconditioning period, an equilibrium period, and a data collection period The length of the data collection phase varies based on whether the heat pump operates in a steady state or transient condition.
Annex C gives a flow chart of the procedure and schematically represents most of the different test sequences that are possible when conducting a heating capacity test
The test room reconditioning apparatus and the heat pump under test shall be operated until the test tolerances specified in Table 4 are attained for at least 10 min
A defrost cycle can conclude a preconditioning phase, after which the heat pump must function in heating mode for a minimum of 10 minutes before entering the equilibrium period.
The preconditioning period should conclude with either an automatic or manually induced defrost cycle when evaluating performance under the outdoor air application rating conditions specified in Table 3 and Tables 18 to 21.
For units with defrost cycles under standard rating conditions, the water flow rate must be adjusted to the appropriate inlet and outlet water temperatures 20 minutes after the completion of a manually or automatically induced defrost cycle.
The equilibrium period immediately follows the preconditioning period or the defrost cycle and a recovery period of 10 min that ends a preconditioning period
A complete equilibrium period is one hour in duration
Except as specified in 4.4.4.7, the heat pump shall operate while meeting the test tolerances specified in Table 4
The data collection period immediately follows the equilibrium period
Data shall be sampled at equal intervals that span every 30 s or less, except during defrost cycles as specified below
Test results
The capacity tests require specific data to be recorded, as outlined in Table 6 This table provides essential general information but does not restrict the scope of the data to be collected.
These data shall be the mean values taken over the data collection period, with the exception of time measurement
Table 6 — Data to be recorded
Measured quantity of result Unit Calorimeter Air enthalpy method Water enthalpy method
3) Thermodynamic quantities a) Indoor heat exchanger
- external/internal static pressure difference Pa X X -
- volume flow rate, q m 3 /s X - rate of condensate Kg/s X X -
Measured quantity of result Unit Calorimeter Air enthalpy method Water enthalpy method
- liquid pump speed setting, if applicable - X X
- pressure difference kPa X X b) Outdoor heat exchanger
- external/internal static pressure difference Pa X X -
- liquid pump speed setting, if applicable - X X X
- pressure difference kPa X X X c) Heat recovery heat exchanger
- pressure difference kPa - - X d) Heat transfer medium (other than water)
- density (if needed for calculation) kg/m 3 X X X
- specific heat (if needed for calculation) J/kg.K X X X e) Refrigerant a
- saturated vapour/bubble point temperature °C - - X
- rotational speed of open type min -1 - - X
- power input of motor (only for open compressor type)
- compressor frequency for inverter type Hz x x x
Measured quantity of result Unit Calorimeter Air enthalpy method Water enthalpy method g) Calorimeter
- ambient temperature around the calorimeter °C X - -
- temperature of the water entering the humidifier °C X - -
- operating cycle with defrost min X X x
- SHR b W/W X X - a Only for unit with remote condenser. b Only for air-to-air and water-to-air units.
4.5.2 Cooling capacity and heat recovery capacity calculation
The average cooling and heat recovery capacities are calculated based on the recorded capacities during the data collection period or by using the average temperature and volume flow values from that same period.
The average heating capacity is calculated using the recorded heating capacities during the data collection period or by averaging the temperature and volume flow values obtained throughout that period.
For equipment that undergoes one or more complete cycles during the data collection period, the average heating capacity must be calculated by considering the integrated capacity and the total elapsed time for all complete cycles that occurred within that timeframe.
For equipment that does not complete a full cycle during the data collection period, the average heating capacity is calculated by utilizing the integrated capacity along with the total elapsed time of the data collection period.
The average electric power input is calculated by integrating the electrical power over the same data collection period used for determining the heating, cooling, or heat recovery capacity.
The average electric power input is calculated by integrating the electrical power over the total time corresponding to the complete cycles during the same data collection period used for heat capacity assessment.
The average electric power input is calculated by integrating the electrical power over the same time period used for heat capacity measurement.
5 Electrical consumptions for single duct and double duct units
Determination of power consumption due to standby mode
The unit, whether for cooling only or reverse cycle, enters standby mode via the control device, if one is available After a duration of 10 minutes, the energy consumption during this period is measured and recorded as the standby mode consumption, denoted as \$P_{SB}\$.
For heating only units, the measurements are made in the same way, after the following test condition
Table 7 — Test conditions for power consumption due to standby mode for heating only units
Outdoor heat exchanger Indoor heat exchanger
Inlet wet bulb temperature °C Heating mode
All air conditioners and heat pumps except single duct units
Determination of power consumption in off-mode
After conducting the standby mode test, the unit should be switched to off mode, if possible, while still plugged in After a duration of 10 minutes, the residual energy power is measured, which is then considered the off mode consumption, denoted as \( P_{\text{OFF}} \).
Electricity consumption
The electricity consumption for cooling mode in single duct units (Q SD) and double duct units (Q DD) is determined by the rated power input (P EER) multiplied by the specified number of "on mode" hours, as outlined in the regulation, which is set to equal 1.
It is expressed in kWh/h
The electricity consumption for heating mode in single duct units (Q SD) and double duct units (Q DD) is determined by the rated power input (P COP) multiplied by the specified number of "on mode" hours, as outlined in the regulation, which is set to equal 1.
It is expressed in kWh/h
6 Air flow rate measurement of ducted units
For ducted units, the manufacturer shall declare the rated air flow rate, indoor and/or outdoor as applicable, measured according to Annex J
7 Heat recovery test for air-cooled multisplit systems
Test installation
The heat recovery capacity of the system is assessed using a three-room calorimeter or the air enthalpy method, which can involve two or three rooms In the three-room setup, one room is outdoors while the other two are indoors, with one maintained at heating conditions and the other at cooling conditions For the two-room air enthalpy method, one room is kept at outdoor conditions and the other at the common indoor conditions specified in Table 21 of EN 14511-2:2013.
The calorimeter room must meet the specifications outlined in Annex A, while the air enthalpy method requires test facilities that comply with the standards set in Annex B.
To test a heat recovery system using the calorimeter method, a three-room calorimeter test facility is required One room will house the indoor units operating in cooling mode, while another room will contain the indoor units in heating mode The outdoor unit will be installed in the third room.
7.1.3 Three-room air-enthalpy method
For optimal performance, indoor units operating in cooling mode should be grouped in one room, while those in heating mode should be placed in a separate room Additionally, the outdoor unit must be installed in a third room.
7.1.4 Two-room air-enthalpy method
All indoor units, either operating in cooling or heating mode, are assembled in one indoor room The outdoor unit shall be installed in the other room
All heating units must be linked to a shared plenum, while all cooling units should connect to a separate common plenum, as specified in Annex B.
Test procedure
The heat recovery test shall be carried out with all operating indoor units
For ducted indoor units, the external static pressure for each unit is regulated by adjusting a damper in the duct that links the unit's discharge area to the common plenum.
Test results
Test results are recorded and expressed as specified in 4.5
The references of the indoor units operating in cooling mode and of the indoor units operating in heating mode shall be specified
General information
The test report shall at least contain: a) date; b) test institute; c) test location; d) test method; e) test supervisor; f) test object designation:
3) name of the manufacturer; g) type of refrigerant; h) mass of refrigerant; i) properties of fluids; j) reference to this European Standard.
Additional information
When conducting tests, it is essential to note the details provided on the rating plate, along with any other pertinent information Specifically, it should be indicated whether the test is performed on a new unit or one that is already in use For tests on used units, it is important to include the year of installation and details regarding the cleaning of the heat exchanger tubes.
Rating test results
The rating capacities, power inputs, COP, EER, internal or external static pressure shall be given together with the rating conditions
Table 8 provides a template for the test results to be reported for single duct and double duct units
Table 8 — Test results for single duct and double duct units
Standard rating conditions, indoor air dry bulb (wet bulb) temperature in cooling mode - °C
Standard rating conditions, outdoor air dry bulb (wet bulb) temperature, in cooling mode - °C
Rated capacity for cooling P rated kW
Rated power input for cooling P EER kW
Rated Energy efficiency ratio EER rated -
Electricity consumption in cooling mode
- single duct unit Q SD kWh/h
- double duct unit Q DD kWh/h
Standard rating conditions, indoor air dry bulb (wet bulb) temperature, in heating mode - °C
Standard rating conditions, outdoor air dry bulb (wet bulb) temperature, in heating mode - °C
Rated capacity for heating P rated kW
Rated power input for heating P COP kW
Rated Coefficient of Performance COP rated -
Electricity consumption in heating mode
- single duct unit Q SD kWh/h
- double duct unit Q DD kWh/h
Power consumption in off-mode P OFF kW
Power consumption in standby mode P SB kW
informative) Rating of indoor and outdoor units of multisplit and modular heat recovery
The calorimeter enables simultaneous capacity determination on both the indoor and outdoor sides In cooling mode, the indoor capacity is assessed by balancing the cooling and dehumidifying effects against measured heat and water inputs Meanwhile, the outdoor capacity serves as a confirming test, balancing heat and water rejection on the condenser side with the measured cooling output.
The calorimeter must be adequately sized to prevent any obstruction to the intake or discharge openings of the equipment To maintain optimal airflow, perforated plates or suitable grilles should be installed at the discharge opening, ensuring face velocities do not exceed 1.0 m/s It is essential to allow sufficient space in front of any inlet or discharge grilles to avoid airflow interference A minimum distance of 1 meter should be maintained from the equipment to the side walls or ceiling, except for console-type equipment and single duct units, which should be positioned normally relative to the wall Ceiling-mounted equipment must be installed at least 1.8 meters above the floor Table A.1 provides suggested dimensions for the calorimeter, but adjustments may be necessary to accommodate specific equipment sizes and space requirements.
Rated cooling capacity of equipment Suggested minimum inside dimensions of each room of calorimeter
NOTE For larger capacity equipment, the following dimensions could be recommended:
− Width ≥ 4 times the unit width;
− Height ≥ 2,5 times the unit height;
− Length ≥ 1,5 times the unit length
Each compartment must be equipped with reconditioning equipment to ensure proper air flow and maintain specified conditions The indoor compartment requires heaters for sensible heat and a humidifier for moisture, while the outdoor compartment needs systems for cooling, dehumidification, and humidification Additionally, the energy supply must be controlled and measured effectively.
Calorimeters utilized in heat pumps must possess the ability to heat, humidify, and cool both rooms, as illustrated in Figures A.1 and A.2 Alternatively, maintaining the rating conditions can be achieved through methods like rotating the equipment.
Reconditioning apparatus for both compartments must include fans capable of delivering air flows that are at least double the amount discharged by the tested equipment in the calorimeter Additionally, the calorimeter should have the capability to measure or determine the specified wet- and dry-bulb temperatures in each compartment.
Key A indoor unit (wall mounted)
Figure A.1 — Typical calibrated ambient room type calorimeter
Key A indoor unit (wall mounted)
Figure A.2 — Typical balanced ambient room type calorimeter
A pressure-equalising device must be installed in the partition wall separating the indoor and outdoor compartments to ensure balanced pressure This device includes multiple nozzles, a discharge chamber with an exhaust fan, and manometers for monitoring compartment and airflow pressures.
To ensure proper air flow between compartments, it is essential to use two devices mounted in opposite directions or a reversible device The manometer pressure tubes must be positioned to avoid interference from air discharged by the equipment or the exhaust from the pressure-equalizing device Additionally, the fan or blower responsible for exhausting air from the discharge chamber should allow for adjustable air flow through methods like variable speed drives or dampers Importantly, the exhaust from this fan or blower must not impact the inlet air to the equipment.
Temperature gradients and airflow patterns in both indoor and outdoor compartments arise from the interaction between the reconditioning apparatus and test equipment Consequently, the resulting conditions are unique and depend on the specific combination of compartment size, arrangement and size of the reconditioning apparatus, as well as the air discharge characteristics of the equipment being tested.
The measurement points for the specified test temperatures, including wet bulb (or dew point) and dry-bulb temperatures, must meet certain criteria Firstly, the measured temperatures should accurately reflect the surrounding conditions of each piece of equipment, simulating real-world applications for both indoor and outdoor environments Secondly, it is essential that the air temperature at the measurement point remains unaffected by any air discharged from the equipment, necessitating that measurements be taken upstream of any recirculation caused by the equipment.
Air sampling tubes shall be positioned on the intake side of the equipment
The interior surfaces of the calorimeter compartments must be constructed from non-porous materials, ensuring that all joints are sealed to prevent air and moisture leakage Additionally, the access door should be securely sealed using gaskets or other appropriate methods to maintain airtight and moisture-proof conditions.
During the defrost cycle of a heat pump, it is essential to halt the indoor air flow Consequently, measures must be implemented to also stop the air flow from the test apparatus to both the indoor and outdoor units during this defrost period.
To ensure the reconditioning apparatus operates during the defrost period, it is essential to bypass the conditioned air around the equipment, ensuring it does not contribute to the defrosting process Additionally, a watt-hour meter should be utilized to measure the total electrical input to the equipment being tested.
The calibrated room-type calorimeter, depicted in Figure A.1, must be insulated, including the separating partition, to limit heat leakage (including radiation) to no more than 5% of the equipment's capacity Additionally, an air space should be maintained beneath the calorimeter floor to allow for free circulation.
Heat leakage can be assessed from either the indoor or outdoor compartment by closing all openings and heating the compartment with electric heaters to a temperature at least 11 K above the ambient temperature It is essential to maintain a constant ambient temperature within ± 1 K around all six enveloping surfaces, including the separating partition If the partition's construction matches that of the other walls, the heat leakage through it can be calculated based on its proportional area.
To calibrate heat leakage through the separating partition, a test is conducted as previously described The temperature on the adjoining side of the partition is then increased to match that of the heated compartment, effectively eliminating heat leakage through the partition Meanwhile, a temperature differential of 11 K is maintained between the heated compartment and the ambient environment surrounding the other five enveloping surfaces.
The difference in heat input between the first test and second test shall permit the determination of the leakage through the partition alone