Certification system of air filter quality (CAF mark) KOREA AIR CLEANING ASSOCIATION
1. Overview What is the certification system of air filter quality (CAF mark)? It is a mark granted by the KACL depending on the results of strict and thorough quality certification tests by certified test agencies based on the quality certification system of the air filters produced in Korea established by Korea Air Cleaning Association. Procedure for certifying the CAF mark [Figure 1] Procedure for certifying the CAF mark - 2 -
1. Apply for and receive the CAF certification test (company > association) 2. Check the application reception, factory inspection and sampling (association > company) 3. Request the performance evaluation test to designated (national research institute) test agencies (association > test agency) 4. Notify the performance evaluation test (test agency > association) 5. Open the review board on granting the CAF certification mark 6. Issue the CAF report from the Korea Air Cleaning Association (association > company) 7. Apply for issuing the CAF certificate and its certified notification (company > association) 8. Issue the CAF certification and certified document and manage follow-up 2. Test method and certification standard Test method - Test method for high performance air filter [Performance test item for HEPA/ULPA filters] The test items for the air filter are as below and is performed for more than 3 samples with tested samples. Other test items including tightness, flame resistance, durability, heat wind resistance and humidity resistance for the HEPA filter are classified as special test items and may be tested through additional cooperation between the user and the supplier. a) Particle collection efficiency test b) Pressure loss test c) Scanning leakage test [Particle collection test] The test procedure is as follows. 1) Install the filter unit into the unit fixture of the test device without leakage. 2) Run the blower to reach a defined level. 3) Measure the static pressure difference between upstream and downstream of the filter unit by the differential manometer connected to the measuring hole for static pressure and consider it as the pressure loss. 4) Measure the pressure loss from the rating wind volume. 5) Consider the value deducting the pressure loss of the device as the pressure loss before installing the test filter. - 3 -
[Scanning leakage test] The test procedure is as follows. 1) Maintain the filter unit into the unit fixture of the test device without leakage. 2) Run the blower to adjust to the rating level. 3) Supply the clean air and check whether it has a small background value enough to effectively measure the particle collection efficiency with defined particle concentration in the downstream. 4) The particle concentration for the test upstream shall not exceed the simultaneous error of 5% for light-scattering automatic particle counter, the downstream value shall be within a range sufficiently larger than the background value and the test particle concentration in the upstream or downstream is alternatively or simultaneously measured after checking that the test particle concentration in the upstream is stabilized. For the alternative measurement, take caution on the concentration changes in the upstream, find out the correlative coefficients for each particle diameter of the light-scattering automatic particle counter for simultaneous measurement and the difference shall be calibrated if any. The collection efficiency of the filter unit is evaluated by test particles and calculated by the formula below. Where: η : Particle collection efficiency (%) C1 : Filter in the channel in the center of the particle diamter Coefficient in the unit upstream (before filtration) (ea/l) C2 : Filter in the channel in the center of the particle diamter Coefficient in the unit downstream (after filtration) (ea/l) [Pressure loss test] The test procedure is as follows. 1) Install the filter into the test device. Firmly install the leakage membrane not to have leakage between the device and the test filter. 2) Adjust the facial speed of the filter to the rating wind volume. 3) Locate the detection hole of the light-scattering automatic particle counter in the clean - 4 -
air in the downstream and measure after the gauge becomes stabilized. 4) The entrance of the sampling probe is set with the square and the size is decided for the sampling to have inhalation with constant speed at the probe entrance in line with the sampling air volume of the test particle conctration device. 5) The scanning of the sampling probe is maintained within 30mm from the surface of the filter downstream and the speed is slower than 50mm/s. however, the probe with shorter than 25mm of one side is less than Vs in the formula below. Vs = 2L Where: Vs : Scanning speed (mm/s) L : Length of a square probe side (mm) The scanning is performed for all the filters including the joint of the remaining material and the frame and joint with the external filter frame. 6) The evaluation is continuously performed with the interval less than 2 seconds of the measurement of the light-scattering automatic particle counter. The leakage is evaluated as below. Where: NL : Number of particles judged leakage for every judgment time (ea/tj) Set up the NV and the Tj more than 5. NV : Upstream coefficient for every 1 minute (ea/min) If counters with different inhalations are used in the upstream and the downstream, the value is converted assuming that the same counter is used. PL : Allowed penetration ratio of the filter, benchmark value (%) Tj : Time for leakage judgment (less than 2s) η0 : Nominal or guarantee value of the filter particle collection efficiency (%) K : Allowed magnification, decided through agreement with the user Generally select 1, 2, 10, 100 or 1000. - 5 -
1From ventilator 2cleaning filter 3test particle generator 4infuse pipe for test particles 5more than A 6bell mouse 7rectifying grid 8more than B/2 9place measuring static pressure 10measurement range of upstream concentration 11test particle fixture 12place measuring static pressure 13particle counter 14pipe for taking upstream test particles 15gasket 16test material 17pipe for taking downstream test particles 18flow measurement 19orifice [Fig. 2] Test device for the filter unit [Fig. 3] Test device for the scanning leakage - 6 -
- General air-conditioning and ventilating air filter: Follow the ANSI/ASHRAE Standard 52.2-2007. - Air filter for the air cleaner [KS C 9325] [Measuring dust collection efficiency] Generate a certain amount of particles from the test particle generator with the dust collection efficiency tester and inhale the particles diluted to a certain concentration with the clean air using the inhalation pump at 0.95m/s for large, 0.69m/s for mid and 0.55m/s for small partcles (here, the nominal error ranges within ±5%). Here, simultaneously measure the particle concentration before and after the filter with the light-scattering gauge and calculate the dust collection efficiency as below. Where: η: Dust collection efficiency (%) Ci : Particle concentration with 0.3 μm diameter before the filter (no. of particles / cm3) C0 : Particle concentration with 0.3 μm diameter after the filter (no. of particles / cm3) [Measure the pressure loss] Inhale the air through the filter with the speeds of 0.55m/s, 0.69m/s and 0.95m/s using the pressure loss tester, measure the pressure different based on the filter with the pressure gauge or manemeter and calculate the pressure loss as below. p =p1 p2 Where: p:pressure loss (Pa) mmh2o p1 :Pressure in front of the filter (Pa) mmh2o p2 :Pressure behind the filter (Pa) mmh2o Item and standard for certification [Certification standard for high performance (HEPA/ULPA) filter] - HEPA filter: The air filter with the dust collection rates higher than 99.7% for DOP monodispersed particles of 0.3μm at the rating wind speed. - ULPA filter: Using the aerosol with the range of 0.12 to 0.17μm of the particles, the minimum dust collection efficiency shall be higher than 99.999% (the maximum particle pentration rate of 0.001%, @5.3cm/min) and shall contain the dried filter in the sturdy frame. - 7 -
[Certification standard for the air-conditioning and ventilating air filter] [Performance standard of the air filter] Spec WxDxT mm Dust collection efficiency % Pressure loss Pa Facial speed m/s Large [for 49.5m2] 400 330 35 0.95 Mid [for 33m2] 380 320 35 Higher than 90% Lower than 60% 0.69 Small [for 16.5m2] 330 230 25 0.55-8 -
3. List of review board Review board for the CAC certification mark No Name Title Company Name Position Remarks 1 Youngok Park Manager Korea Institute of Energy Research 2 Bangwoo Han Chief researcher Korea Institute of Machinery & Materials 3 Gangho Ahn Professor Hanyang University 4 Kyunghoon Yoo Chief researcher Korea Institute of Industrial Technology 5 Donghwan Kim Center chief FITI Test Research Institute Clean Fossil Fuel Reserach Center Green Environment Machine Research HQ Department of Mechanical Engineering Convergent Technology R&D Division Research department Industrial Material Analysis Center 6 Jindo Chung Professor Hoseo University Department of Environment Engineering 7 Soonbak Gwon Doctor Korea Institute of Industrial Technology Environment Fire Research Team 8 Wanje Cho Deputy manager Korea Land & Housing Corporation Future Strategy Division 9 Jinwook Yoon CEO Tena Co., Ltd. 10 Yunkyu Lee Chief Korea Institute of Construction Technology Green Building Lab 11 Youngmin Cho Professor Kyunghee University Environment studies and environment engineering - 9 -
4. Status of Certified Test Organizations Status of certified test organizations as of 2013 (Period of consignment: January 1, 2013 - December 31, 2014) No Organization Remarks 1 Korea Institute of Industrial Technology - 10 -