EXP COVID-19 Offices White Paper

RISK REDUCTION | 27

COSATRON Particles in a room vary in size, concentration and settling time. What happens to these particles depends greatly on their size. Two primary forces at work affect particle movement. One is air movement created by the HVAC system and the second is the naturally occurring electrical fields that exist in all rooms. Large droplets settle out fast while smaller droplets do not. A very large percentage of indoor air particles are three microns or smaller in size. The very small particles are not affected by air currents. Particles of this size are influenced to a much larger degree by the naturally occurring electrical fields in and around the space they are in. CosaTron creates an atmosphere where the natural process of coagulation is increased using a “non- homogeneous in-duct electrical field” in the air handling system. (29 . The non-homogeneous electrical field used in this system is comprised of two grids mounted a small distance apart from one another. One grid is a high voltage (HV) field and the other is a high frequency (HF) field. The rate of particle collisions is increased by this field which results in a rapid decrease in small particles (submicron) and a rapid increase in particle size. Generically, this process is called “excitation technology.” As particles increase in size; they can then be picked up by the HVAC system and moved through ducts and trapped by the filters to be removed. CosaTron does not affect the virus, however, it will create an environment where the smaller particles in a room collide and become larger causing them to “fall out” of the air as they grow in size or be caught in air currents to allow them to travel back to the air handling system where other technologies can work. NIST EVALUATION TOOL Researchers at the National Institute of Standards and Technology (NIST) have built an online tool - The Fate and Transport of Indoor Microbiological Aerosols (FaTIMA) tool that considers factors including ventilation, filtration and aerosol properties to estimate the concentration of aerosols a person might encounter in a room. This tool can be used to evaluate options for reducing occupant exposure to the novel coronavirus. The following chart indicates how modifying an HVAC system by increasing the outside air amount or changing the efficiency of the filter reduces the airborne integrated exposure level.

Figure 32. Possible terminal application of far UV (28)

Figure 33. NIST Airflow Model could help reduce indoor exposure to aerosols carrying coronavirus (45)

Figure 34. FaTIMA Tool Input Form (NIST Multizone Modeling) (46)

AIRBORNE INTEGRATED EXPOSURE

AVERAGE AIRBORNE CONCENTRATION

12,000 10,000 8,000 6,000 4,000 2,000 0

0% -10% -20% -30% -40% -50% -60%

2.50 2.00 1.50 1.00 0.50 0.00

0% -20% -40% -60% -80%

Figure 35. FaTIMA results for options for typical private office

Current MERV 8 FILTERS

MERV 8 + 100% OA

MERV 13 Filters + 10% OA

Current MERV 8 FILTERS

MERV 8 + 100% OA

MERV 13 Filters + 10% OA

Integrated Exposure (# s/m 3 )

Airborne Concentration Average (9h) % Reduction

Airborne Concentration Average (9h) (# s/m 3 )

% Reduction