Other Air Treatments

The technical expertise of ASHRAE is concentrated in its Technical Committees (TCs), Task Groups (TGs), and Technical Resource Groups (TRGs). Find a TC list here.

Bill Bahnfleth, PhD, PE to discuss the new ASHRAE Pandemic Task Force and Mechanical Systems and COVID-19. Dr. Bahnfleth is the Chair of th…

"Our results show that installing an air purifier may increase the droplet spread,"

Sterilox fog is safe and simple to use, and can reduce levels of nosocomial pathogens by a factor of almost 10(7).

*******

Absolute Ventilation vs ACH. Wells-Riley equation: C=S(1-e –Iqpt/Q). In models of airborne infection, it is absolute ventilation that is a major determinant of disease transmission

A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs ar...

***!!!!***** "Air change rates were calculated by periodically injecting a tracer gas" "Monthly average air change rates varied from 0.44 h−1 in October and November to 1.30 h−1 in July.... The mean overnight (midnight to noon) air change rate was 0.56 h−1 (0.42 SD, N=2439); mean daytime (noon to midnight) value was 0.73 h−1 (0.65 SD, N=2012). Yearly mean tracer gas decay rates were nearly identical in all rooms of the house, varying only from 0.63 to 0.68 h−1. The mean relative SD of the hourly average air change rates across all rooms (not including the attic) was 15% (SE=0.2%). The air change rate fell below 0.35 h−1 on 1087 occasions out of 4451 measurements; thus, the home fell below the recommended value (ASHRAE Standard 62) about 24% of the time." "Indoor–outdoor temperature differences had a clear effect on air change rates, with extreme temperature differences of 30°C resulting in an increase of about 0.5–0.6 air changes per hour." "experiments with keeping multiple windows open... Although higher rates of 3–4 h−1 were achieved for a brief time, the average over 12–36 h was never more than 2 h−1"

Effects of ACH on particle removal compared with on particle size

The VF Cumulus atomized fogging machine efficiently and safely applies disinfectant to the targeted areas. The VF Cumulus Triple-Atomizer Fogger is ready to disinfect your rooms with clean, even coverage right out of the box. It is easy to set-up and requires no clean-up. AS A BONUS we are including a bottle of EfferSan Disinfecting tablets which turn any water you add to the fogger into pathogen fighting Hypochlorous Acid (HOCL), perfect for disinfecting your spaces of all viruses and bacteria. HOCL is the least toxic and safest disinfectant on the market maintaining 99.9% effectivity on s...

Many airborne viruses have been shown to be sensitive to ambient humidity, yet the mechanisms responsible for this phenomenon remain elusive. We review multiple hypotheses, including water activity, surface inactivation, and salt toxicity, that may account for the association between humidity and vi …

****!!!!****

Humidity can have a large effect on the dispersion of virus particles, pointing to heightened coronavirus contagion risks in dry, indoor conditions during the winter months.

{Excellent simple explanation of important topics}

Recommended rates of outdoor make up air in some common types of rooms - banks, assembly halls, hotels and many more. Smoking and air supply rates

Area method, Air change method, Occupancy Method, Heat removal method--in cubic feet per minute

{Calcs with example air purifiers} ACH or Air Changes Per Hour is a metric that tells us how many times an HVAC device can fill up the full volume of a room with air.

Innovating for a Safer World. TOMI™ Environmental Solutions, Inc. is a global decontamination and infectious disease control company, providing environmental solutions for indoor/outdoor surface disinfection through manufacturing, sales and licensing of our premier product SteraMist™ BIT™. Learn more!

Occupational Safety and Health Administration methods to measure Chlorine Dioxide concentrations using various sampling methods

Standards for requirements for air exchange rate in rooms (relating to air flow)

The role of relative humidity in the aerosol transmission of influenza was examined in a simulated examination room containing coughing and breathing manikins.Nebulized influenza was coughed into the examination room and Bioaerosol samplers collected ...

"If a gaseous emission sample is analyzed and found to contain water vapor and a pollutant concentration of say 40 ppmv, then 40 ppmv should be designated as the "wet basis" pollutant concentration. "

10L Backpack Disinfectant Fogger and one case of COVID-19 PureroxTM disinfectant.PureroxTM is a proven, proprietary disinfectant that is being used to kill 99.99% of viruses. Can easily be applied with the electric sprayer and is on the EPA List N for use against COVID-19 (87518-1 (hsp2O)). It has the shortest contact time of any HOCL disinfectants of 1 minute and is 100...

Heating and Humidifying in relation with infiltration of outside air

"ABS plastic is used in the production of diffusers because they are made out of oil-based resources and boast of a much higher melting point (more temperature resistant) than PP plastic. As such, they cannot be broken down or corroded by the acidic chemical composition of some essential oils." "Plastic aside, other components of a diffuser like the metal atomizer and absorption rings are specifically designed to withstand the corrosiveness of essential oils." "Diffusers are much more powerful than humidifiers. They break down essential oils into an ultra-thin fragranced mist that's easily dispersed over a wider distance for longer periods. The cool or warm mist generated by humidifiers from the vaporization of water molecules is only able to travel over shorter distances. This low dispersion range is because humidifiers usually have larger atomizer, which subsequently produces bigger, thicker, and heavier mist concentration."

Made with ethyl alcohol

Water diffusion is a system that makes the water last longer and can produce finer water vapor. The quiet operation works much like a wicking cloth. The membrane is waterproof, so there is no moisture on the outside, but the water vapor passes through without a problem. These additions to humidifiers are optional, but work better to maintain humidity levels and moisture in the air.

Classroom ventilation rates often do not meet building standards, although it is considered to be important to improve indoor air quality. Poor indoor air quality is thought to influence both children’s health and performance. Poor ventilation ...