Interactive Home Ventilation Tool

Interactive Home Ventilation Tool
Updated Feb. 9, 2022

Small particles that people breathe out can contain virus particles, including the virus that causes COVID-19.  If a guest visits your home, improving ventilation (air flow) can help prevent virus particles from accumulating in the air. Good ventilation, along with other preventive actions, like staying 6 feet apart and correctly wearing masks, can help prevent you from getting and spreading COVID-19.

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 after using the tool below.

How can I decrease the level of virus particles during and after a guest visits my home?

Select the options below to see how particle levels change as you adjust ventilation settings.

(To create additional scenarios, including to adjust the length of the visit and size of the home, see the expanded model from the National Institute of Standards and Technology.)

Your Results
End of 4-hour visit

0% particle reduction achieved in your home by using ventilation.

Living room with poor ventilation and with many virus particles in the air.; Image of a closed windowImage of a room
1 Hour Later

0% particle reduction achieved in your home by using ventilation. You can decrease particles even more by continuing to ventilate for an extra hour.

Living room with poor ventilation and with many virus particles in the air an hour later. Image of a closed windowImage of a room

The risk of getting COVID-19 varies according to individual susceptibility and the number of virus particles to which a person is exposed. The fewer virus particles in the air, the better.


Image of a room
Image of a closed window











Living room with poor ventilation and with many virus particles in the air.










Living room with poor ventilation and with many virus particles in the air an hour later.