Filtration and UV disinfection Synergy By: Normand Brais P.Eng, Ph.D. National Air Filtration Association NAFA TECH 2014, Kissimme, FL April 3 2014.

Filtration and UV disinfection Synergy

By: Normand Brais P.Eng, Ph.D.

National Air Filtration AssociationNAFA TECH 2014, Kissimme, FL

April 3 2014

Content

1) UV Fundamentals

2) Cooling Coils Disinfection

3) Filtration Fundamentals

4) Filtration + UV : complementarity

1) Fundamentals of UV light UV-A (400-315 nm) Sun glasses UV-B (315-280 nm) Sun tanning UV-C (280-200 nm) Germicidal UV UV-V (200-30 nm) V = Vacuum : O2 O3

DNA : Watson and Crick 1953

Reproduction: a molecular copying machine

UV Sterilization mechanism: Dymerisation of Thymines pairs

Fundamental Principle of UV disinfection

UV Dose = intensity x time

joule/ m2 watt/m2 sec

The larger the Dose, the more alterations to the DNA,

leading to Sterilization

Direct Mathematical Correlation

N0 = Initial number of micro-organisms

N(t) = Number of micro-organisms surviving at time “t”

I = UV radiation intensity in W/m2

t = exposure time in seconds

Dose = I x t, in Joule/m2

K = susceptibility coefficient in m2/joule

k values: Susceptibility of microbes to GUV

Organism Group Member of Group

Staphylococcus aureus

Streptococcus pyogenes

Escherichia coli

Pseudomonas aeruginosa

Vegetative Bacteria

Serratia marcescens

Mycobacterium tuberculosis

Mycobacterium bovis

Mycobacteria

Mycobacterium leprae

Bacillus anthracis

Bacillus cereus

Bacterial Spore

Bacillus subtilis

Aspergillus versicolor

Penicillium chrysogenum

Fungal Spores

Stachybotrys chartarum

Vegetative bacteria

Mycobacteria

Bacterial spores

Fungal Spores

Most Susceptible

Least Susceptible

Figure 2. General ranking of suceptibility to UVC inactivation of microorganisms by group.

2) Cooling Coils

Surface Disinfection

Coil without adequate Filter

Coil with good Filters: is it clean ?

Samples taken on Clean Looking Coils

Difference between

virus, bacteria, fungi

and

inert mineral dust ?

inert dust can’t grow

and multiply !

• About multiplication…by 2

2 x 2 x 2 x 2 x….x 2 = ?

10 times = 1,02420 times = 1 million +30 times = 1 billion +

What lives on cooling coils ?

A) Mold spores UV Dose for 90% kill

1. Aspergillus Niger D90= 448 mJ/cm2

2. Cladosporium wemecki D90= 448 mJ/cm2

3. Penicillium D90= 224 mJ/cm2

B) Bacteria

4. Legionella Pneumophilia D90= 2.5 mJ/cm2

5. Pseudomonas Aeruginosa D90= 2.2 mJ/cm2

UV dose required against Aspergillus and Cladosporium

UV Dose: 448 mJ/cm2 for 90% kill = 1 log

UV Dose: 896 mJ/cm2 for 99% kill = 2 log

UV Dose: 1344 mJ/cm2 for 99.9% kill = 3 log

UV Dose: 1792 mJ/cm2 for 99.99% kill = 4 log

UV Dose: 2240 mJ/cm2 for 99.999% kill = 5 log

and so on…

How much UV does it take to keep a coil clean ?

Disinfecting Aspergillus at 99% within 1 hour

requires a UV intensity of :

Intensity = 896 mJ/cm2/(3600 sec)

= 0.25 mW/cm2

= 250 μW/cm2

Just the tip of the iceberg…

Example : • coil of 10 ft x 10 ft • 10 inches thick, 10 fins/inch

Coil face = 100 ft2

Total coil surface = 20,000 ft2 ! !

Coil heat transfer surface –vs- face area

Area ratio = 2 X Fins per inch X Coil thickness

Inter-Fins UV Propagation Coil FINS

Coil Depth

Move away for better results

Inter-Fins UV Propagation

1 reflection : UV = 80%

2 reflection : UV = 80% x 80%= 64%

3 reflection : UV = 80%x80%x80%= 51%

4 reflection : UV = 80%x80%x80%x80%= 41%

5 reflection : UV = 80%x80%x80%x80%x80%= 33%

6 reflection : UV = 80%x80%x80%x80%x80%x80%= 26%

7 reflection : UV = 80%x80%x80%x80%x80%x80%x80%= 21%

8 reflection : UV = 80%x80%x80%x80% x80% x80% x80% x80%= 17%

9 reflection : UV = 80%x80%x80%x80%x80%x80%x80%x80%x80%=13%

10 reflection : UV = 80%x80%x80%x80%x80%x80%x80%x80%x80%x80%=11%

Aspergillus Niger: time to reach 99% disinfection

inside a Coil

At Coil face, 250 μW/cm2: 1 hourAt 2’’ depth, 113 μW/cm2: 2.2 hoursAt 4’’ depth, 51.4 μW/cm2: 4.9 hoursAt 6’’ depth, 23.3 μW/cm2: 11 hoursAt 8’’ depth, 10.6 μW/cm2: 24 hoursAt 10’’ depth, 4.8 μW/cm2: 52 hoursAt 12’’ depth, 2.2 μW/cm2: 115 hoursAt 14’’ depth, 1.0 μW/cm2: 254 hoursAt 16’’ depth, 0.45 μW/cm2: 561 hours

Aspergillus Niger: time to reach 99% disinfection

inside a Coil

At Coil face, 500 μW/cm2 : 0.5 hourAt 2’’ depth, 227 μW/cm2: 1.1 hoursAt 4’’ depth, 103 μW/cm2: 2.4 hoursAt 6’’ depth, 46.6 μW/cm2: 5.4 hoursAt 8’’ depth, 21.1 μW/cm2: 12 hoursAt 10’’ depth, 9.6 μW/cm2: 26 hoursAt 12’’ depth, 4.3 μW/cm2: 58 hoursAt 14’’ depth, 2.0 μW/cm2: 127 hoursAt 16’’ depth, 0.9 μW/cm2: 281 hours

Aspergillus Niger: time to reach 99% disinfection

inside a Coil

At Coil face, 1000 μW/cm2 : 0.25 hourAt 2’’ depth, 453 μW/cm2: 0.55 hoursAt 4’’ depth, 205 μW/cm2: 1.2 hoursAt 6’’ depth, 93.1 μW/cm2: 2.7 hoursAt 8’’ depth, 42.2 μW/cm2: 5.9 hoursAt 10’’ depth, 19.1 μW/cm2: 13 hoursAt 12’’ depth, 8.7 μW/cm2: 29 hoursAt 14’’ depth, 3.9 μW/cm2: 64 hoursAt 16’’ depth, 1.8 μW/cm2: 140 hours

UV rules of thumb –vs- Coil Thickness

Coil thickness Avg UV on face Gross Power

Coil ≤ 12’’ 250 μW/cm2 1 Watt/ft2

12’’< Coil ≤ 14’’ 500 μW/cm2 2 Watt/ft2

14’’< Coil ≤ 16’’ 1 000 μW/cm2 4 Watt/ft2

16’’ < Coil ≤ 18’’ 2 000 μW/cm2 8 Watt/ft2

Coil Disinfection

•Elimination of biofilms formation

•Lower pressure drop

•better heat transfer

•energy savings

•Improved occupant’s wellbeing

•UV system design criteria:

• Intensity

• Homogeneity

• Inter-fin penetration

UV COIL DISINFECTION

10 ft x 10 ft Coil

InstallationCoil Width 120 in Lamp Position on Coil* UPSTREAMCoil Height 120 inDistance between lamp and coil 18 in Lamp Fouling* NO FOULING

Lamp Length 40 inNumber of Rows 2 Total number of lamps and fixtures required 4Number of Lamps per Row 2 Total Input Power Required 413 W

Coil surface UV Irradiation Intensity Survival time of ASPERGILLUS NIGERwith disinfection rate of 99 %

Minimum UV Irradiation Intensity 545 µW/cm2 Maximum survival Time 28 minAverage UV Irradiation Intensity 1102 µW/cm2 Average Survival Time 14 minMaximum UV Irradiation Intensity 1705 µW/cm2 Minimum Survival Time 9 min

Information contained in this CoiClean sizing is subject to change without notice. The information contained herein is proprietary and confidential. Sanuvox does not make and expressly disclaims any representation or warranties as to the completeness, accuracy, or usefulness of the informatation in this

document. The data used to estimate the resulting values are derived from data supplied by the end user who takes responsibilty for its accuracy. Sanuvox does not warrant that use of such information wil l not infringe any third party rights, nor does Sanuvox assume any l iabil ity for damages or costs of any kind

that may result from use of such information.

*Lamp Cooling Effects will occur on a Downstream Installation

*Lamp Fouling wil l occur on a Downstream Installation

0

12

24

36

48

60

72

84

96

108

120

0 12 24 36 48 60 72 84 96 108 120

Coil height, H [in]

Coil width, W [in]

Coil surface irradiation intensity544-660,1 660,1-776,2 776,2-892,3 892,3-1008,41008,4-1124,5 1124,5-1240,6 1240,6-1356,7 1356,7-1472,81472,8-1588,9 1588,9-1705

0

12

24

36

48

60

72

84

96

108

120

0 12 24 36 48 60 72 84 96 108 120

Coil height, H [in]

Coil width, W [in]

Survival times (minutes)

8,8-10,7 10,7-12,6 12,6-14,5 14,5-16,3 16,3-18,2

18,2-20,1 20,1-22,0 22,0-23,9 23,9-25,8 25,8-27,6

Petri dish samples taken with UV ON

3) How Filters Work

The MPP Chasm

Most Penetrating Particle size

HEPA Filters: MPP Chasm

Filters MERV efficiency (source: NAFA)

4 - Filling the Chasm with UV

4) FILTER+UV SYNERGY

FILTERS: good on small or large microbes

Between 0.02 and 1 micron, filters efficiency drop

HEPA filters:

also a drop of efficiency between 0.1 and 0.4 micron

UV : efficient in this size range

viruses are easy targets for UV.

UV can complete the job

D 90% SIZE UV microJ/cm2 UV microJ/cm2 UV microJ/cm2 UV microJ/cm2 UV microJ/cm2

microJ/cm2 Type micron 2500 5000 10000 20000 40000Parvovirus H-1 0,092 m2/J 2500 virus 0,022 fever similar to adenovirus. 89,9741% 98,9948% 99,9899% 100,0000% 100,0000%Echovirus 0,217 m2/J 1060 virus 0,024 Meningetis, affects children. 99,5595% 99,9981% 100,0000% 100,0000% 100,0000%Coxsachievirus 0,111 m2/J 2072 virus 0,027 Common cold in fall or summer. Colds, acute respiratory disorder.93,7651% 99,6113% 99,9985% 100,0000% 100,0000%Norwalk virus 0,0304 m2/J 7566 virus 0,029 Gastroenteritis. Airborne transmission. Common on cruise ships.53,2334% 78,1288% 95,2165% 99,7712% 99,9995%VEE 0,0419 m2/J 5489 virus 0,065 Vancomycin-resistant Enterococcus64,9186% 87,6930% 98,4854% 99,9771% 100,0000%Reovirus 0,03358 m2/J 6849 virus 0,075 Colds, fever, pneumonia 56,8074% 81,3440% 96,5195% 99,8789% 99,9999%Adenovirus 0,039 m2/J 5897 virus 0,079

Symptoms ressemble common cold. Can be epidemic in 62,2808% 85,7726% 97,9758% 99,9590% 100,0000%

influenza A virus 0,119 m2/J 1933 virus 0,098 Causes flu. Can cause epidemia inside buildings.94,8953% 99,7394% 99,9993% 100,0000% 100,0000%Coronavirus (SARS) 0,377 m2/J 610 virus 0,113 Comon colds and lung infections. 99,9919% 100,0000% 100,0000% 100,0000% 100,0000%Mycoplasma pneumoniae 0,2791 m2/J 824 bacteria 0,177 Causes pneumonia in 20% of cases. 99,9067% 99,9999% 100,0000% 100,0000% 100,0000%Neisseria catarrhalis/meningitidis0,05233 m2/J 4395 bacteria 0,177 Second leading cause of Meningitidis, also causes pharyngitis.72,9707% 92,6942% 99,4663% 99,9972% 100,0000%Newcastle disease 0,144 m2/J 1597 virus 0,212 Exposure of humans to infected birds (for example in poultry processing plants) can cause mild conjunctivitis and influenza-like symptoms97,2676% 99,9253% 99,9999% 100,0000% 100,0000%Coxiella burnetii 0,1535 m2/J 1498 bacteria 0,283 Transmitted from animals to humans. Q fever: causes chil ls, headache, fatigue.97,8453% 99,9536% 100,0000% 100,0000% 100,0000%Haemophilus influenza 0,0599 m2/J 3840 bacteria 0,285 Major cause of meningetis. Affects infants, otitis media, sinusitis.77,6311% 94,9963% 99,7496% 99,9994% 100,0000%Proteus vulgaris/mirabilis 0,07675 m2/J 2997 bacteria 0,291 Pneumonia, ooportunistic infections.85,3210% 97,8453% 99,9536% 100,0000% 100,0000%Vaccinia virus 0,153 m2/J 1503 virus 0,307 97,8182% 99,9524% 100,0000% 100,0000% 100,0000%Measle virus 0,1051 m2/J 2188 virus 0,329 Rubeola,affects children, nosocomial. Airborne transmission in schools ventilation92,7741% 99,4779% 99,9973% 100,0000% 100,0000%Pseudomonas aeruginosa 0,1047 m2/J 2197 bacteria 0,494 Pneumonia, nosocomial, indoor growth in dust, water, humififiers. Common Hospital AI92,7015% 99,4673% 99,9972% 100,0000% 100,0000%E. Coli 0,15611 m2/J 1473 bacteria 0,5 Source:feces. Found in food, meat and water. Causes diarrhea, often deadly.97,9814% 99,9593% 100,0000% 100,0000% 100,0000%Legionella pneumophila 0,44613 m2/J 516 bacteria 0,52 Legionnaire's disease. Pontiac fever, pneumonia, deadly in 15% of cases.99,9986% 100,0000% 100,0000% 100,0000% 100,0000%Serratia marcescens 0,28653 m2/J 803 bacteria 0,632 99,9225% 99,9999% 100,0000% 100,0000% 100,0000%Mycobacterium tuberculosis 0,4721 m2/J 487 bacteria 0,637 TB infects 1/3 of world population.Causes Tuberculosis. Nosocomial.99,9993% 100,0000% 100,0000% 100,0000% 100,0000%Listeria monocytogenes 0,2303 m2/J 999 bacteria 0,707 Food processing industry pathogen. Causes diarrhea. Elderly and pregant women99,6841% 99,9990% 100,0000% 100,0000% 100,0000%Salmonella 0,221 m2/J 1041 bacteria 0,800 Food processing industry pathogen. Causes diarrhea. Elderly and pregant women99,6014% 99,9984% 100,0000% 100,0000% 100,0000%MRSA 0,113 m2/J 2035 bacteria 0,866 Methicil l in-resistant Staphylococcus aureus94,0691% 99,6482% 99,9988% 100,0000% 100,0000%

NoteName k

SI unit

Example of Combined efficiency: MERV 16 Filter + UV ≥ HEPA

SIZE UV microJ/cm2 Merv 16 Combination HEPA Combo Merv 16+UV

Type micron 15000 FILTER Filter+UV alone Improvementinfluenza A virus 0,119 m2/J virus 0,098 Causes flu. Can cause epidemia inside buildings.100,0000% 81,00% 100,0000% 99,99% 0,01%Coronavirus (SARS) 0,377 m2/J virus 0,113 Comon colds and lung infections.100,0000% 80,00% 100,0000% 99,98% 0,02%Mycoplasma pneumoniae 0,2791 m2/J bacteria 0,177 Causes pneumonia in 20% of cases. 100,0000% 72,00% 100,0000% 99,94% 0,06%Neisseria catarrhalis/meningitidis0,05233 m2/J bacteria 0,177 Second leading cause of Meningitidis, also causes pharyngitis.99,9610% 72,00% 99,9891% 99,94% 0,05%Newcastle disease 0,144000 m2/J virus 0,212 100,0000% 69,00% 100,0000% 99,95% 0,05%Coxiella burnetii 0,1535 m2/J bacteria 0,283 Transmitted from animals to humans. Q fever: causes chills, headache, fatigue.100,0000% 70,00% 100,0000% 99,97% 0,03%Haemophilus influenza 0,0599 m2/J bacteria 0,285 Major cause of meningetis. Affects infants, otitis media, sinusitis.99,9875% 71,00% 99,9964% 99,97% 0,03%Proteus vulgaris/mirabilis 0,07675 m2/J bacteria 0,291 Pneumonia, ooportunistic infections.99,9990% 71,00% 99,9997% 99,97% 0,03%Vaccinia virus 0,153 m2/J virus 0,307 100,0000% 72,00% 100,0000% 99,97% 0,03%Measle virus 0,1051 m2/J virus 0,329 Rubeola,affects children, nosocomial. Airborne transmission in schools ventilation100,0000% 73,00% 100,0000% 99,98% 0,02%Pseudomonas aeruginosa 0,1047 m2/J bacteria 0,494 Pneumonia, nosocomial, indoor growth in dust, water, humififiers. Common Hospital AI100,0000% 89,00% 100,0000% 99,99% 0,01%E. Coli 0,15611 m2/J bacteria 0,500 Source:feces. Found in food, meat and water. Causes diarrhea, often deadly.100,0000% 90,00% 100,0000% 99,99% 0,01%Legionella pneumophila 0,44613 m2/J bacteria 0,520 Legionnaire's disease. Pontiac fever, pneumonia, deadly in 15% of cases.100,0000% 91,00% 100,0000% 99,99% 0,01%

NoteName k

Custom unit

A proof by example : In-Vitro Fertilization Clinics

IVF clinics with best HEPA filtration

Fertilization success rate stagnated at 20 to 30%

When UV was added to HEPA

Success rate jumped at 70 to 85% ! !

Independent Studies

Published by : THE LANCET Medical Journal

“Impact of Ultraviolet Germicidal Lights Installed in the Ventilation Systems of Office Buildings on Workers Health and

Well Being”

Richard Menzies MD MSc1,2, Julia Popa BEng MEng1, James A Hanley PhD2, Thomas Rand PhD3, Don Milton MD Dr.

PhD4.

From :1.Respiratory Epidemiology and Clinical Research Unit, Montreal

Chest Institute, 2.Department of Epidemiology and Biostatistics of McGill University3.Dep’t of Biology, St. Mary’s University, Halifax, Nova Scotia, 4.Department of Environmental Health, Harvard School of Public

Health, Boston.

The LANCET paper highlights

771 Employees from 3 office buildings participated in the study. UV ON for 4 weeks UV OFF for 12 weeks 3 cycles totalling 48 weeks. Repeated twice, over 2 years.

When UV were ON :

• 40% reduction in respiratory symptoms

• 20% overall reduction in all symptoms

• 30% reduction in mucosal symptoms

These benefits were greatest for those with known allergies.

Conclusions When properly engineered with adequate

software, UV eliminates coil biofilms and

saves Energy $$$

UV improves overall performance of filters

Just like for Filtration, UV Fundamentals

are also well defined in ASHRAE Handbook

Working hand in hand with

good filtration practice,

a well engineered

Ultraviolet system

brings a boost to

building hygiene and

energy efficiency.

Thank you !