Performance tests consist of conducting fuel load cycles which must burn in a given time. By analysing the flue gases, the heat output and efficiency of the appliance can be determined.

In safety test both the temperature of the equipment and temperatures from a set distance from the appliance are measured, which need to be taken into account when installing the equipment

La entrada Solid fuel appliance performance and safety tests se publicó primero en CEISLAB.

During the nominal heat output and reduced heat output tests the concentration of these compounds in the combustion exhaust gases can be determined, whose content is limited under ecodesign regulations.

La entrada Determination of nitrogen oxides (NOx), organic gaseous carbon (OGC) and particulate matter emissions se publicó primero en CEISLAB.

Performance of climate control equipment is obtained by dividing the compensated thermal load between the energy consumption used to compensate the said load.

With respect to air conditioning or heat pump equipment, it is the cooling or heating power divided by the consumed energy.

In general terms, we differentiate between 2 types of performance:

• Performance obtained for and from a single operating temperature condition and the thermal load of the sample, as defined in the standard EN 14511:
  • EER – Energy Efficiency in Refrigeration mode
  • COP – Coefficient of Operating Performance in heating mode
• Those obtained by combining the EER or COP performances obtained at different temperature conditions and thermal load according to the standard EN 14825.
  • SEER – Seasonal Energy Efficiency in Refrigeration mode
  • SCOP – Seasonal Coefficient of Operating Performance in heating mode

To calculate SEER and SCOP, the hours over the year are also considered in which the device is in either of the non-active modes.

La entrada Performance se publicó primero en CEISLAB.

            In turn, it is divided into:

Sensitive cooling power: This is the quantity of heat that the sample carries from the indoor environment and is reflected as a decrease in room temperature.

Latent cooling power: This is the quantity of heat that the sample carries from the indoor environment and is reflected as a decrease of water in the air (humidity).

Heating capacity: This is the quantity of energy transported over a unit of time between the outdoor heat exchanger (acting as evaporator) and the indoor heat exchanger (acting as condenser).

Test methods:

The cooling and heating capacity measurement is fundamental to characterise the performance of climate equipment. It defines its capacity to heat and/or cool a liquid or gas medium, covering the demands of the facility or room where it is installed.

Power can be obtained via different test methods depending on the type of product under assessment, the magnitude of the expected cooling or heating capacity, the type of exchange (air or water / salt water) and the precision requirements. The most widely employed methods, also affording the most accurate measurements are:

• Calorimetric method

This applies to equipment that use Air as the heat exchange medium. It consists of determining the quantity of energy we supply in a number of quasi-adiabatic test rooms (with controlled, minimum energy exchanges through the walls) to compensate for the cooling or heating effect of the assessed sample, while maintaining the temperature and air humidity constant.

This is the most accurate method to assess cooling or heating power on air exchange equipment. At CEISLAB it is applied to equipment with design power of up to 12 kW.

• Enthalpy method

This is applied to equipment in which air or water / salt water is used as the heat exchange medium. It consists of determining the quantity of energy supplied by the equipment to the exchange medium, and 3 parameters are determined:

1. Mass quantity, whether air or water / salt water crossing over the equipment heat exchanger.
2. Enthalpy or specific heat of the exchange medium before entering the heat exchanger.
3. Enthalpy or specific heat of the exchange medium at the output of the heat exchanger.

Cooling capacity = 1 * (2 – 3) or heating capacity = 1 * (3 -2)

At CEISLAB this method is applied to equipment of up to 100 kW.

La entrada Heating and cooling capacity se publicó primero en CEISLAB.

Measurement of operating limits consists of determining the following:

• In heating mode (TOL): the lowest external temperature at which the heat pump still supplies heating power according to the manufacturer.
• In cooling mode: the highest external temperature at which the heat pump still supplies cooling power according to the manufacturer.

Operating temperature range: Start-up and running tests

The equipment must be capable of starting and/or operating within the utilisation limits (temperatures and flows) specified by the manufacturer.

If operation outside of the temperature range can damage the equipment, it must be supplied with safety devices that ensure that the equipment is not damaged when the operating limits indicated by the manufacturer are exceeded, and that it can resume operation when it returns within the said limits. The manufacturer must indicate which safety devices are used and the operating conditions.

Freeze test in cooling mode

This test is carried out in cooling mode to check the consequences of possible freezing of the air in the inside.

When the equipment has been running for 6 hours in set conditions, or after the final freeze cycle has completed after those 6 hours, a check is made for ice in the evaporator, that there is no dripping ice in the equipment and water does not drip or comes out of the equipment into the test area.

Heat carrier fluid flow shut-off

Correct operation of the safety devices in the equipment are checked by simulating each of the following errors over a 30 minutes period.

1. Flow shut-off to the outdoor heat exchange of the heat carrier fluid.
2. Flow shut-off to the indoor heat exchange of the heat carrier fluid.
3. Flow shut-off to the outdoor heat recovery of the heat carrier fluid, where applicable.

The equipment must be capable of running after the flows are restored for 30 minutes when the compressor starts running again.

Total electrical power failure

This test consists of simulating a total power failure lasting approximately 5 seconds. The equipment must have reached stable operating conditions before the power failure simulation in one of the nominal cooling modes and heating modes, as applicable.

The equipment must start up automatically within 30 minutes. If the manufacturer states that the equipment does not start automatically, a fault detector must be used.

A check is made for any damage to the equipment during the tests and if any of the safety devices have been triggered during the power failure.

Condensate drainage test and condensation in the casing

The test is carried on air-air and water (salt water)-air equipment, operating in cooling mode with the possibility of humid air condensation.

The condensate drainage includes the condensate that forms in the casing. During the 4 hour test, the water condensate must not drip, run or be ejected from the equipment, except through the drain.

La entrada Operating limits se publicó primero en CEISLAB.

• Standby (this is the mode when the device remains partially switched off and can be enabled again by a controlling device (remote control, timer, etc.).
• Thermostat Off (the device operating mode in which the cooling or heating demands of the room are covered and the device disconnects the cooling compressor).
• Power Off (in this mode the device is completely disconnected and cannot be reactivated by means of a controlling device, external signal or timer).
• Crankcase heater (in this mode the device activates a compressor oil heating device, thus avoiding the refrigerant from concentrating in the compressor oil and thereby avoiding damage to the compressor when it starts operating).

Test methods

Power consumption during the thermostat off mode (Pto)

When the unit has been operating for 30 minutes in test conditions D in the cooling mode (only for refrigeration or reversible units), the thermostat set point is increased until the compressor stops. Energy consumption in standby mode is taken from the total energy consumption measured in the unit to determine the energy with the thermostat off for a period of time no less than 1 hour.

The same principle is applied in the heating mode, but the thermostat set point is reduced until the compressor stops and after the unit has been operating for 30 minutes in test conditions D.

Power consumption during the standby mode (Psb)

After the condition A test in cooling mode, the unit is stopped using the controlling device. After 10 minutes the residual energy consumption represents energy consumption in standby mode.

For heating only units, measurements are taken in the same way after testing under test conditions D in heating mode.

Power consumption in crankcase heating mode (Pck)

If the crankcase heater is on during standby mode, power consumption is considered to be equal to the electricity power consumption in standby mode.

If the crankcase heater does not operate during measurements in standby mode, after completing the test in temperature conditions B in heating mode, the unit is switched off using the controller and energy consumption of the unit is measured for 8 hours. The average input power over 8 hours must be measured.

Power consumption during the power off mode (Poff)

After the standby mode test, the unit is completely switched off. After 10 minutes the residual energy power for consumption while off is measured.

If there is not a switch to disconnect the device, the power in off mode is considered to be equal to the standby power mode.

La entrada Power consumption se publicó primero en CEISLAB.

Test methots:

Sound power is a parameter that is inherent to mechanical elements or objects. It serves to characterise and compare the sound level emitted by an object. Sound power does not depend on the distance to or from the object emitting the sound being measured as is the case of acoustic pressure. Neither does it depend on the area where the emitting object is located. It exclusively depends on the emitting object itself.

Essentially, sound power can be determined by 4 mechanisms:

1. Free field methods: The sound power is determined by the acoustic pressure measurements taken around the emitting object in an area where sound is propagated without any reflection. This is typically conducted outdoors or in partially sound-proofed test rooms where the surfaces are treated to absorb sound waves from the sound pressure they receive.
2. Reverberating field methods: This is a variation on the former method which requires a reverberating area in which the surfaces in the test room reflect the sound pressure waves in multiple directions. The acoustic pressure measurement is not taken around the emitting object, but rather within the acoustic field induced by the emitting object in the room.
3. Acoustic intensity (the average value over time resulting from acoustic pressure at a single point, and then multiplying the instantaneous speed of the particles at that point.[W/m^2]) assessment around the emitting object.
4. Based on the speed of vibration of the surfaces of the emitting object.

At CEISLAB we determine the power by employing the reverberating field method and intensimetry.

Reverberating field methods:

Special test rooms are required to apply this method. CEISLAB implements the methods defined in EN ISO 3741:2010

There are two reverberating field methods. The so-called direct method and the comparison method.

When using the direct method, we determine the sound power on the basis of acoustic pressure level measurements in the room when the test object is operating, and from the reverberation time measurements (T10 or T15 extrapolated to obtain T60), which allow us to then determine how the sample itself, the air surrounding it and the surfaces dampen the acoustic energy.

When we use the comparison method, a known acoustic source is used for which there is an sound power calibration chart with emissions under certain conditions. The test consists of comparing average acoustic pressure levels recorded in the test room when the sample is tested while operating, and when only the reference sound emitting source is operating. The difference between the recorded pressure levels in both cases is added to the power emitted by the reference source in test conditions to obtain the power of the test sample.

For larger equipment or those with multiple internal units, we generally use intensimetry methods to determine the sound power levels. This test method does not require a specific test environment and also has some interesting advantages owing to its immunity to background noise, although not all acoustic environments allow working with high-precision levels.

In intensimetry methods we use the set of EN ISO 9614 standards. We draw an imaginary surface around the test sample at a set distance from it. We determine the acoustic intensity levels on the defined surfaces by using an intensity sensor (acoustic instrument fitted with 2 facing condenser microphones separated by a few millimetres, and their electronics work in a strictly coordinated manner or in phases.), sweeping or sampling at given positions to measure the intensity on the defined surfaces with the intensity sensor. Finally, the sound power is calculated as the result of the acoustic intensity and the area of the measurement surfaces.

CEISLAB has two twin 215 m^3 reverberating chambers, with climate capabilities which mean we are able to determine the sound power levels in air-conditioning equipment, heat pumps, liquid coolers, etc., in controlled temperature and humidity conditions.

Larger equipment is tested in large climate chambers where cooling, heating and performance tests are also carried out, capable of volumes of up to 550 m^3.

La entrada Sound Power se publicó primero en CEISLAB.