The importance of Eurovent certification
Eurovent Certification was established with the purpose to create a common set of criteria for the rating of products within the Air Conditioning and Refrigeration market. Eurovent certification is made up of different programmes, each corresponding to one type of refrigeration or air-conditioning product. The specific Air Handling Unit (AHU) Programme considers a manufactures range of AHU products as long as at least one product is below 3 m3/s and considers an AHU to be a factory made encased assembly or flat-packaged unit that consists of a fan or fans and other necessary equipment to perform one or more of the following functions: circulating, filtration, heating, cooling, heat recovery, humidifying, dehumidifying and mixing of air with the unit suitable to be used with ductwork.
The importance of the Eurovent Certification Mark is the guarantee it provides, detailing that the products have been submitted for independent testing and that they will perform as declared. This mark guarantees specifiers, installers and end users that products marketed by the manufacturer have been accurately rated, giving them confidence that the AHU equipment will operate in accordance with the design specifications, the energy cost will be correctly stated and therefore the supplied product will correspond to the initial investment.
For manufacturers, Eurovent Certification programmes provide the ground for fair competition, on equal terms and based on comparable data. Furthermore gaining confidence between manufacturers and specifiers, and through the specification of certified products, the engineer's tasks can be made easier with the assurance that the declared catalogue data are accurate and verified independently.
An AHU is a ventilation device connected to ductwork which distributes conditioned air throughout a building/space either as a separate supply and / or extract unit, or acting as a combined supply and extract unit. The AHU is normally a ‘box’ containing various active components ,fan sections, cooling and heating coils, air filter systems, sound attenuators, humidification, dampers and importantly heat recovery. Eurovent considers both the mechanical characteristics and the performance characteristics within the certification programme:
Casing Strength (CS): The CS is defined as the largest deformation of the sides of the unit under, positive or negative pressure, the unit without permanent deformation; given, as the difference in distance from a reference plane outside the unit, to the external unit surface with and without test pressure. Measured in maximum relative deflection mm x m-1, with D1 being the best to D3 the lowest. The casing strength is an important indicator for AHU quality, enabling units to be double-stacked and giving the unit potentially a longer life expectancy, also as a general rule a weak casing can lead to high leakage rates.
Casing Air Leakage (CAL): The CAL is the amount of air that can pass through the AHU casing, under defined pressure conditions. To determine the casing air leakage rate, the tests are performed at an internal negative pressure of 400 Pa for unit working in under pressure only and for the part of the unit working in overpressure, the test is made with an internal positive pressure of 700 Pa. Depending on the results the classification is with L1 being the best to L3 the lowest. This parameter is important from an indoor air quality point of view and also for the fan energy consumption.
Filter bypass Leakage (FBL): This characteristic is crucial in understanding the amount of air that is not actually filtered, this will determine the potential indoor air quality, with the higher rating giving the best potential air quality. F9 being the best to F5 the lowest, measured as a maximum percentage (%) of air bypass around the filter cells, leakage rate k with test conditions set at an internal pressure of 400 Pa.
Thermal Transmittance (TT): Providing the knowledge about how good the thermal insulation of the AHU’s casing can be and represents how much energy is transmitted through 1m² of casing and for an indoor- outdoor temperature difference of 1oC, with T1 being the best to T5 the lowest measured in (U) W/m2.K. This will directly affect the cooling and/or heating capacity of the unit and efficiency of the system and dependent of the application can stop the AHU from “sweating”, preventing corrosion.
Thermal Bridging Factor (TBF): TB1D1 being the best to TB5 the lowest measured in (kb) W.m-2.K-1, is the ratio between the lowest temperature difference between any point on the external surface and the mean internal air temperature and the mean air-to-air temperature difference. This is important again due to the potential efficiency losses in the heating / cooling systems but is relative to the frame of the AHU.
Acoustical insulation of casing: Determines the acoustic insulation performance of the AHU’s casing.
All characteristics are certified and tested in accordance with EN 1886.
The below table shows the general Eurovent mechanical characteristic classification with green ratings showing premium products, yellow rating medium segment products and red ratings being low segment products. In order for an AHU product to be considered in a particular segment lowest performing characteristic define the segment.
The certified mechanical characteristics benchmark the units overall quality and expected performance however, Eurovent also considers and tests internal component performance as per below:
- Air flow (fan and motor performance) - Available static pressure - power input
- Heat recovery efficiency
- Cooling capacity
- Heating capacity
- Pressure loss on water side
- Airborne sound power level
- Octave band in-duct sound power level
The key to the importance of Eurovent certification is not only the mechanical and performance characteristics which are independently tested by Eurovent but also the review of declared performance of everything from the selection software, through the manufacturing process and paperwork issued to client, to the final complete supplied unit, ensuring the product does not deviate from the initial declaration. Eurovent requests a model box unit selection that is built according to specifications presented in manufacturer’s literature, this selection and completed unit is then independently tested and is used to establish mechanical, thermal and acoustical performance according to the relevant EN standards. If the declared performance differs from the actual tested result, the participant will be required to adjust the performances within the selection software not only for the specific product but also on all similar products, or to withdraw the relevant products from the market. This is an ongoing process with annual reviews of the selection software and declared performance to ensure no software changes would affect the output rating of the unit and regular independent testing of units to ensure the manufacturing process is unchanged. The certification programme is robust and can provide complete product confidence.
Daikin Applied UK are a proud participant of the Eurovent Certified Performance programme for Air Handling Units with both the Caleppio di Settala (Milan) factory and the UK manufacturing facility in Cramlington (Newcastle) both currently certified for 2017 and onwards. Whilst we always strive to exceed client expectations, Eurovent Certification for both the product and supporting software provides additional assurance of our quality and AHU performance.
Daikin Applied AHU performance (result based on SP65)