Dynamic Commercial Image
Dynamic Commercial News
November 2009
Inside This Issue
More on H1N1
Solutions from Dynamic
Visit Dynamic at Greenbuild International
Sales Engineers
IAQ Links
Join Our Mailing List
Swine flu concerns and outbreaks are in the news everyday.  As air cleaning experts we are constantly asked what can/should be done to help mitigate the risks of transmission.  Last month, we focused on personal practices and what can be done in the home.  This month the focus will be commercial buildings.  With more and more news and scientific evidence about H1N1 surfacing every day, we thought we would keep you apprised of information from the latest published reports from ASHRAE and the EPA.  Newer data suggests that HVAC systems may contribute far more both to transmission of disease and, potentially, to the reduction of transmission risk.

Carl Mitchell, Vice-President Sales
More on H1N1

ASHRAE Offers Position Documents

According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), in a position document dated June 24, 2009: 
  • Many infectious diseases are transmitted through inhalation of airborne infectious particles termed droplet nuclei
  • Airborne infectious particles can be disseminated through buildings including ventilation systems
  • Airborne infectious disease transmission can be reduced using dilution ventilation, specific in-room flow regimes, room pressure differentials, personalized and source capture ventilation, filtration, and ultraviolet germicidal irradiation (UVGI)
They go on to state that ASHRAE should commit to improving the health of individuals who occupy buildings and should support further research on engineering controls to reduce infectious disease transmission.
Implications for Engineers
According to ASHRAE, there are three pertinent issues for engineers:
1) the impact of ventilation on disease transmission,
2) the disease for which ventilation is important for either transmission or control,
3) the control strategies that are available for implementation in the buildings of interest.
Some infectious agents are secreted in large droplets, such as may be coughed or sneezed. These droplets usually fall to the ground within three feet, and transmission via the airborne route to persons greater than three feet distant is considered unlikely so that a six-foot protection ring is considered needed. Many diseases transmitted from person-to-person follow this pathway.
Because (large) particles are quite heavy and drop quickly, general dilution and even enclosures and exhaust ventilation will not significantly influence airborne particle concentrations and the potential for transmission. Although some of the moisture content may evaporate, this does not happen quickly enough to change large droplets (>10 microns) into droplet nuclei (<10 microns). Droplet nuclei particles may be transported through ventilation systems, as has been documented for tuberculosis, Q-fever, and measles. If influenza transmission occurs not only through direct contact or large droplets, as is the long-standing public health tradition, but also through the airborne route, as newer data suggest, HVAC systems may contribute far more both to transmission of disease and, potentially, to reduction of transmission risk. Some biological agents potentially used in terrorist attacks may be purposefully transmitted through HVAC systems, such as small pox, plague pneumonia, and hemorrhagic viruses.  The following technical solutions are of interest: dilution ventilation, laminar and other in-room flow regimes, differential room pressurization, personalized ventilation, source capture ventilation, filtration (central or unitary), and ultraviolet germicidal irradiation (upper room, in-room and in the air stream).
Ventilation represents a primary infectious disease control strategy through dilution of room air around a source (CDC 2005).  Directed supply and/or exhaust ventilation such as laminar flow and displacement is important in several settings including operating rooms (AIA 2006).
Room pressure differentials are important for controlling airflow between areas in a building (Garner et al. 1996).  For example, TB isolation rooms are kept at negative pressure with respect to the surrounding areas to keep potential infectious agents within the rooms; hospital rooms with immuno-compromised individuals are kept at positive pressure to keep potential infectious agents out of the rooms.
Another strategy from an exposure control perspective could be the use of personalized ventilation systems that supply 100% outdoor air, highly-filtered, or UV disinfected air, (i.e., the ventilation provision per person) directly to the occupant-breathing zone (Cermak et al. 2006; Sekhar et al. 2005).
Additionally, providing supplemental (either general dilution or exhaust/capture in a specific location) ventilation in locations in which infectious sources are located will reduce exposure potential, such as what is done in TB isolation rooms (CDC 2005). The value of these strategies is unproven and individual case study may be required to justify their application.
The addition of highly efficient particle filtration to central ventilating systems is likely to reduce the airborne load of infectious particles. This control strategy may prevent the transport of infectious agents from one area, such as patient rooms in hospitals or lobbies in public access buildings, to other occupied spaces, when these areas share the same central ventilation system. Such systems are common in buildings in the U.S.  Additionally, local efficient filtration units (either ceiling mounted or portable) reduce local airborne loads and may serve purposes in specific areas such as healthcare facilities or high-traffic public occupancies (Miller-Leiden et al 1996; Kujundzic et al. 2006).
Filter efficiency varies with particle size, so the type of filtration required in order to be effective will vary with the type of organism and the aerosol that carries it. ASHRAE Standard 52.2 describes a minimum efficiency reporting value (MERV) for filter efficiency at various particle sizes and HEPA filtration may not be necessary. Specific personnel safety procedures may be required when changing filters, depending on the types of organisms and other contaminants that have been collected on the used media.
There are three general UVGI strategies: installation into ventilating ducts, irradiation of the upper zones of occupied spaces, and in-room irradiation after one occupant and before the next. All depend upon inactivation of viable agents carried in droplet nuclei. In both the duct and in-room UVGI, the amount of radiation applied can be much higher compared to what can be used for upper-zone UVGI, resulting in higher exposures and quicker inactivation. When effectively applied, duct-mounted UVGI functions similarly to filtration. Upper-zone UVGI, when effectively applied, inactivates infectious agents locally and can be considered in public access and high-traffic areas such as cafeterias, waiting rooms, and other public spaces. In-room UVGI can be considered as a kind of disinfection between successive occupants of a room. There is research that shows UVGI in both the upper-room and in-duct configuration can inactivate some disease transmitting organisms and that it can affect disease transmission rates. Additional research is needed showing clinical efficacy specifically in occupancies with high-risk sources (such as jails, homeless shelters, and health-care facilities) and facilities where high-risk susceptible individuals congregate, such as nursing homes and healthcare facilities. Such research may lead to other recommended changes in HVAC system design.
To review the entire ASHRAE position paper on Airborne Infectious Diseases,
click here.
From the EPA

The following information has been excerpted from a June 3, 2009 presentation published by the Federal Interagency Committee for Indoor Air Quality on the EPA website entitled Swine H1N1 Influenza A: Transmission of Viruses in Indoor Air HVAC System Protection Options.  To view the entire paper, click here.
  • Influenza A causes disease primarily in the lungs as it loves to infect the lower respiratory system.
  • It is not a rhinovirus which primarily causes infection in the nose and upper respiratory system.
  • Since your fingers can't touch your lungs, washing your hands won't likely prevent flu viruses from entering deep into your lungs.
  • NO matter how sterile your hands are, you'll still be fully exposed to airborne Influenza viruses entering and depositing into your lungs to cause disease.
Influenza A likes to multiply at 98.6°which is the temperature of the lower respiratory system. The upper respiratory system-nasal cavity & pharynx-are approximately 93° which rhinoviruses favor for multiplication.  Influenza A infects and destroys its victim's lung tissue. Damaged lung tissue has compromised its protective layers which can lead to pneumonia or massive bacterial infection.
Public Health Officials are offering this advice on preventing the Swine Flu Contagion:
1. Wash your hands, 2.Cover your mouth when you cough, and 3.If you're sick, stay home. This advice ignores studies showing that 30-50% of infected influenza carriers have NO symptoms. It also ignores both human airway and toilet water viral aerosolization. These both are critical modes of airborne contagion within indoor spaces.
Airborne Transmission depends on people to launch viruses into the air. People can shed this many Flu Viruses into the air:
1. Coughing 3,000+
2. Sneezing 3,000+
3. Breathing (Nose) = None, Breathing (Mouth) = Varies
4. Talking/Singing 1,000+
5. Vomiting 1,000+
6. Diarrhea 20,000+   (via Toilet Water Aerosolization)

Toilet Water Viral Aerosolization has drawn increased attention since the SARS outbreak in 2005, although studies dating back as far as 1959 have documented how a toilet flush aerosolizes bacteria and viruses into the air above the bowl.  In 2005 British scientist John Barker replicated the viral load and consistency of diarrhea.  Added to toilet water and flushed, air samples were taken to capture the aerosolized droplets. They were full of thousands of viruses.  But what surprised him was the fact that for 30 minutes afterwards every flush aerosolized additional viruses. It turns out that porcelain is porous enough to harbor viruses (and bacteria).
Impact of Humidity on Droplet Nuclei
Viruses evaporate faster in low humidity (winter) conditions thus
creating more droplet nuclei.  Low humidity allows droplet nuclei to stay airborne longer as the droplets do not absorb water weight which would cause them to fall to the ground. Indoor air currents both created by HVAC systems and people movement assure that droplet nuclei will remain airborne indefinitely. This allows the potential for HVAC systems to redistribute droplet nuclei throughout the building to infect more occupants. 
MERV Rated Filters
To capture significant levels of airborne droplet nuclei, filters must be MERV 13 or greater.
Ultraviolet Germicidal Light 
Ultraviolet Germicidal light is UV light in the "C" band (254 nanometers). It is invisible and is mostly filtered out of sunlight before it reaches earth's surface.  UV-C light sterilizes germs by destroying the A to T bond in their DNA. This prevents them from reproducing and they soon die.  UV-C light was artificially created in the 1880's and later commercially used to kill waterborne viruses & bacteria in France in 1909. By the 1930's Duke University surgeons were using UV light in operating rooms to reduce airborne bacterial and viral infections. In the 1930's and 1940's UV light was used in schools to successfully prevent airborne measles epidemics.

Ultraviolet Light can "Kill"/Sterilize this % of Flu Viruses: 

UVR Rating                    %Viruses Killed/Sterilized
 6-(75mw)                      4.4%
 7-(100mw)                    5.8%
 8-(150mw)                    8.5%
10-(500mw)                  25.7%
13-(2000mw)                69.5%
15-(4000mw)                90.7%
16-(5000mw)                94.9% 
Filters with Ultraviolet Light
Airborne Flu viruses can be captured & sterilized with a combination of MERV Filter & URV rated UV-C Light.  Adding filters and UV together in successive layers can provide a lethal force to prevent distribution of airborne viruses into occupied spaces.  A MERV 10 filter alone captures only 10% or flu whereas adding an ultraviolet rating of 10 triples that total single pass capture/sterilize to 35%.  With a MERV 13 filter, the capture/sterilize rate jumps
to 84% with the addition of UV light. That is a very achievable goal for any indoor space.  Adding additional UV lamps can achieve a total single pass capture/sterilize of 99.9%. 
Combined UV Light & Filtration can Kill or Sterilize Flu this % of Viruses:

MERV & UVR Combined           %Viruses Killed/Sterilized 
      6                                        10%
      7                                        12%
      8                                        19%
     10                                       35%
     13                                       84%
     15                                       97%
     16                                       98.8%  

Photocatalytic Oxidation and Bi-Polar Ionization
Photocatalytic Oxidation is created when Ultraviolet light photons strike Titanium Di-Oxide to create hydroxyl radicals. These newly liberated airborne hydroxyl radicals can rupture and destroy
the cellular material of any germs which they encounter.  Bi-Polar Ionization creates positively and negatively charged oxygen molecules which act like hydroxyl radicals and destroy the cell wall and inner cellular material.
Why Schools are Havens for Flu and Viral Transmission
  • Dry environments - Many schools have 15-25% relative humidity levels indoors! This is the perfect environment for airborne viral transmission. 
  • Low filter efficiency - Many schools have low MERV rated filters like MERV 4-6. You need a MERV 13 or higher to have any real effect on airborne viral capture.
  • No Ultraviolet Lights - Few schools in the U.S. use ultraviolet lights.  Schools with UV lights have enjoyed lower airborne viral transmission rates and higher indoor air quality.
  • Bathrooms with ceiling exhaust fans - Floor level exhaust vents have been shown to reduce virus transmission by toilet water aerosolization.

1. Seal filter racks & HVAC systems.
2. Get the highest MERV rated filter that your filter rack and air handling fan can tolerate.
3. Put as much UV light within your coil plenum to achieve a 99.9% single pass kill rate.
4. Consider Bi-Polar Ionization, Photocatalytic Oxidation and Magnetized Filtration Media Technologies for additional viral sterilization.
5. Install bathroom exhausts 1-12"above the floor.
6. Coughing/sneezing occupants stay at home or wear a mask.
To view the presentation entitled Swine H1N1 Influenza A: Transmission of Viruses in Indoor Air HVAC System Protection Options in its entirety,
click here.

Solutions from Dynamic

Dynamic offers solutions that meet or exceed suggested recommendations

Dynamic V8 Air Cleaning Systems provides MERV 13-16 performance without ionizing or Ozone generation- plus the agglomeration and VOC reduction that you have come to rely on from Dynamic Air Cleaners. The Dynamic V8 can be configured and fine-tuned for a wide range of applications and meets USGBC requirements for LEED points. Read more.

Dynamic 1" V-Bank Air Cleaners and 2" "Super-V"  V-Bank Air Cleaners, Dynamic V-Banks offer an equivalent efficiency of MERV 13 -14 and provide an alternative to bulky bag and cartridge filters.  In addition to improved air quality, Dynamic V-Banks yield substantial operational savings with lower energy costs, lower replacement costs, longer maintenance intervals and lower maintenance costs.  Read more.

2" and 2" Tandem Polarized-Media Electronic Air Cleaners, provide an equivalent efficiency of MERV 13-14 and are designed to fit most commercial applications  Available in 2" individual panels that wire to a single power supply or control panels (optional), air cleaners slide directly into 2" filter tracks in most self-contained package rooftop units. Read more.

Dynamic Sterile Sweep™ Germicidal Systems combine two patented technologies---active polarized-media air cleaning, and traversing UV-C light rays, to capture and inactivate airborne pathogens.

Developed primarily for use in medical and food preparation applications, the Dynamic G375 Germicidal System (pictured above) is self-contained and enclosed in a stainless steel cabinet.  The model GDM1000 is a duct-mounted unit and can be installed inside plenums or ductwork.

The Dynamic Advanced PCO System consists of a high intensity UV-C ultraviolet lamp (254nm) and a Titanium Dioxide PCO catalyst module. Photo-catalytic oxidation (PCO) is an efficient means of eliminating airborne gas-phase contaminants.  Destruction of bacteria and viruses takes place through reactions with hydroxyl radicals and super-oxide ions.  Photo-catalysis does not require extreme temperatures to be effective, and the titanium dioxide material used in many PCO reactors can be incorporated into existing HVAC systems without adversely impacting the system static pressure.  Odors and VOCs are vaporized by the UV light in much the same way that a drop of cold water is vaporized when it drops into a hot skillet. Read more.
Visit Dynamic at Greenbuild International
Dynamic Air Quality Solutions Booth # 5248
This year's USGBC Greenbuild International Conference and Expo promises to be the largest ever.  Sheryl Crow and Al Gore will deliver the keynote on Wednesday, November 11.  Visit Dynamic Air Quality Solutions at booth #5248 on the upper level at the Phoenix Convention Center, November 10-12, 2009. For more information, visit www.greenbuildexpo.org. 
Sales Engineers - Do you have clients that would benefit from this newsletter?

DynamicAQS.com has a wealth of information for Engineers
As you probably already know, registered users at http://www.dynamicaqs.com/commercial/ have access to detailed information such as Dynamic Air Cleaner specifications, drawings and dimensions, logos, artwork & images, the Dynamic Air Q™ Program, and the Dynamic ROI Payback Calculator.
On the homepage, in the lower left-hand margin, there is also a place to sign up engineers for this monthly newsletter.  Sign up your key clients today!
About Dynamic Air Quality Solutions
Since 1982, Dynamic Air Quality Solutions' mission to its customers has been to develop and bring to market innovative, technologically advanced and affordable solutions to help clients optimize air quality, energy consumption, and the environment. For more information, visit our website at www.DynamicAQS.com/commercial/.