To calculate people outdoor airflow rate in breathing zone

TO CALCULATE PEOPLE OUTDOOR AIRFLOW RATE IN BREATHING ZONE PDF
TO CALCULATE PEOPLE OUTDOOR AIRFLOW RATE IN BREATHING ZONE WINDOWS

Open windows and doors, when weather conditions allow, to increase outdoor air flow.

However, this may be difficult to do in cold, hot, or humid weather, and may require consultation with an experienced HVAC professional. In mild weather, this will not affect thermal comfort or humidity.

Open outdoor air dampers beyond minimum settings to reduce or eliminate HVAC air recirculation.

Increase the introduction of outdoor air:.

The following tools identify ways to improve ventilation: Use caution in highly polluted areas when increasing outdoor air ventilation. Not all interventions will work in all scenarios.

TO CALCULATE PEOPLE OUTDOOR AIRFLOW RATE IN BREATHING ZONE PDF

Some of the following interventions are based on the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Guidance for Building Operations During the COVID-19 Pandemic pdf icon external icon. In addition to buildings, vehicles вЂ“ including public transportation such as buses, subways, trains, school buses, carpools, and rideshares вЂ“ are also areas where ventilation improvements can be applied to reduce the spread of the virus and lower the risk of exposure. It will be up to the building owner or operator (with expert consultation as needed) to identify which tools are appropriate for each building throughout the year.

The specific combination of tools chosen for use at any point in time can change. While the list of tools can be universally applied across indoor environments, applying them to different building types, occupancies, and activities under environmental and seasonal changes can be challenging. These ventilation interventions can reduce the risk of exposure to the virus and reduce the spread of disease, but they will not eliminate risk completely. Implementing multiple tools at the same time is consistent with CDCвЂ™s layered approach and will increase overall effectiveness of ventilation interventions. They represent a list of вЂњtools in the mitigation toolbox,вЂќ each of which can contribute towards a reduction in risk. Below is a list of ventilation interventions that can help reduce the concentration of virus particles in the air. Buildings that provided healthy, code-compliant indoor air quality prior to the pandemic can be improved for pandemic occupancy using less costly interventions. Consult experienced heating, ventilation, and air conditioning (HVAC) professionals when considering changes to HVAC systems and equipment. However, ventilation system upgrades or improvements can increase the delivery of clean air and dilute potential contaminants. Reoccupying a building during the COVID-19 pandemic should not, in most cases, require new building ventilation systems. Protective ventilation practices and interventions can reduce the airborne concentrations and reduce the overall viral dose to occupants. The lower the concentration, the less likely viral particles can be inhaled into the lungs (potentially lowering the inhaled dose) contact eyes, nose, and mouth or fall out of the air to accumulate on surfaces. Indoors, the concentration of viral particles is often higher than outdoors, where even a light wind can rapidly reduce concentrations.В When indoors, ventilation mitigation strategies can help reduce viral particle concentration. SARS-CoV-2 viral particles spread between people more readily indoors than outdoors. In addition to ventilation improvements, the layered approach includes physical distancing, wearing face masks, hand hygiene, and vaccination. This approach includes using multiple mitigation strategies, including improvements to building ventilation, to reduce the spread of disease and lower the risk of exposure.

CDC recommends a layered approach to reduce exposures to SARS-CoV-2, the virus that causes COVID-19.

To calculate people outdoor airflow rate in breathing zone