D AN ISH BU IL D IN G R ESEAR C H IN ST IT U T E ( SBI ) /AAL BO R G U N IVER SIT Y C O PEN H AG EN ALIREZA AFSHARI-PROFESSOR

D AN ISH BU IL D IN G R ESEAR C H IN ST IT U T E ( SBI ) /AAL BO R G U N IVER SIT Y C O PEN H AG EN ALIREZA AFSHARI-PROFESSOR

Bedre indeklima med luftfiltrering Netværksmøde i gruppen Luftkvalitet og luftrensning SBi 28.08.2015 2

Aalborg University in Copenhagen Energy and Environment HVAC Group SBi 28.08.2015 3

HVAC Group Development of innovative energy efficient solutions for ventilation of nonindustrial buildings Validation of the solutions through field and laboratory investigations Building simulations (Modelica) CFD (Computational fluid Dynamics) simulations Supporting the foundation for building regulations SBi 28.08.2015 4

HVAC Group Alireza Afshari, SBi/AAU, Niels Christian Bergsøe, SBi/AAU, Peter V. Nielsen, AAU Peter Fojan, AAU, Göran Hultmark, Lindab, Karsten Due, VELUX Natural ventilation system PhD Project Filtration system for indoor environment PhD Project Heat exchnger PhD Project Cooling and heating PhD Project Mechanical ventilation system Centralized: PhD Project Mechanical ventilation system Decentralized: PhD Project SBi 28.08.2015 5

Removal of Ultrafine Particles From Indoor Environment Experimental and Computational Studies of Possibilities, Limitations and Applications Siamak Rahimi Ardkapan Aalborg University Copenhagen, Denmark 2013

Methods Evaluated Air cleaners: Non-thermal plasma (NTP) Corona discharge ionizer (CDI) Portable air purifier (PAP) 3D fibrous filter (3DF) Electrostatic fibrous filter (EFF) Experiments on air cleaners 8

Methods Non-thermal plasma (NTP) Pekárek S. Non-thermal plasma ozone generation. Acta Polytechnica 2003;43(6):47-51 Experiments on air cleaners 9

Methods Corona discharge ionizer (CDI) Experiments on air cleaners 10

Methods Portable air purifier (PAP) Experiments on air cleaners 11

Methods 3-dimensional fibrous Filter (3D Filter) Experiments on air cleaners 12

Methods Fibrous Filters Electrostatic fibrous filter (EFF) Experiments on air cleaners 13

Methods Assessment of air cleaner performance: Efficiency Clean air delivery rate (CADR) Effectiveness By-products Experiments on air cleaners 14

Particle counters Nanto Tracer Mobility Particle Sizer (SMPS Condensation Particle Counter (CPC) Ozone monitor BMT930 and 2B Technologies model 205 TVOC Brüel&Kjær, model 1302 Innova model 1312 RH, Temp. Tinytag Ultra Air velocity Dantec anemometer Methods

Methods The Air Quality Laboratory

Methods The efficiency was calculated using: EEE = C uuuuuuuu C dddddddddd C uuuuuuuu C uuuuuuuu = Concentration of UFPs upstream of the flow (UFP/cm 3 ) = Concentration of UFPs downstream of the flow (UFP/cm3) C dddddddddd

Results Efficiency of the air cleaners for UFPs Experiments on air cleaners 18

Results By-products of the air cleaners in the clean room Experiments on air cleaners 19

Results By-products of the air cleaners in the office room measured in winter The maximum ozone concentrations : No increase in particle concentration!! Experiments on air cleaners 20

Experimental investigations Effectiveness ε = Effectiveness C = pollutant concentration V= volume of the room λ (v+d) = Pollutant removal rate by ventilation and deposition (h -1 ) CADR= Clean air delivery rate (m 3 /h -1 ) 21

Results Effectivenesses of the air cleaners in the clean room Experiments on air cleaners 22

Results Effectivenesses of the air cleaners in the office room Experiments on air cleaners 23

Conclusions An ozone generating, air cleaning technology may increase the level of ozone to a level that exceeds the allowed level It may increase ultrafine particle concentration in a room EFF did not generate ozone, its effectiveness was 0.7 in removing UFPs, while its pressure drop was less than 5 Pa The removal efficiency of an electrostatic fibrous filter was directly correlated with UFP exposure and its composition Experiments on air cleaners 24

SBi 28.08.2015 25

Long Term Performance of Particulate Air-filter in an Office Environment

Objective Experimental analysis of the performance of a particulate air filter In an office environment With and without ionization SBi 28/08/2015 27

Methodology The test rig according to DS/EN 779 standard Airflow rates orifice meter Filtration efficiency UFP before and after the filter Pressure drop Static pressure difference between downstream and upstream SBi 28/08/2015 28

Methodology Pressures - Testo 400 Particle counters Condensation Particle Counter (CPC ), model 3007

Results and discussion Increase in pressure drop due to the air-filter The filter was unused i.e. at the start of the measurements. SBi 28/08/2015 30

Results and discussion Decrease in efficiency of the air-filter due to increase in airflow rates The filter was unused i.e. at the start of the measurements. SBi 28/08/2015 31

Results and discussion Pressure drop across the air-filter during the long term measurements Long term measurements were based on 60 l/s SBi 28/08/2015 32

Results and discussion Efficiency of the air-filter during the long term measurements SBi 28/08/2015 33

Pressure drop increase with time Conclusion Increase in pressure without ionization was same as the increase in pressure drop with ionization After 1500 running hours, increase in pressure drop was 4 Pa The UFP filtration efficiency decreased with time without ionization -- deposition of UFP with ionization -- deposition of the UFP along with the deposition of charged particles Initially the efficiency of air-filter with ionization was up to 50% more than the efficiency of air-filter without ionization However, this difference decreased with time, after 1500 running hours the difference in efficiencies was only 10.5% SBi 28/08/2015 34

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