HOLT Architects Simulates COVID-19 Spread Indoors – No Mask vs. Mask

MariaHOLT News

With global news outlets such as New York Times, CNN, ABC, and Bloomberg, and more locally the SyracuseCoE discussing the airborne transmission of Coronavirus indoors, we wanted to share some studies simulating the spread of COVID-19 droplets in our Ithaca, NY office. We used Computational Fluid Dynamic (CFD) technology, with ME Engineering, to create the simulations, adapting it from its primary use (modeling the spread of smoke particles), to study the spread of the virus.

Part 1: Simulation of Three Coughs | No Mask | 10 Minutes

The first study modeled one person, with no mask, coughing three times over the course of 10 minutes.  The results, which you can view below, show the person’s cough dispersing droplets throughout our entire open studio space – with a very small percentage making it to our mechanical system (HOLT’s Ithaca office has a heat pump system).


Part 2: Simulation of Four Coughs | With Mask | 10 Minutes

Our second video (below), simulates the same one person coughing, but while wearing a mask. The model shows that the mask is extremely effective in containing the highly infectious red cloud to the person’s immediate workstation, but the cloud containing 100%-300% of the human infectious dose can travel 20 feet or more. While the mask is extremely effective in containing a droplet cloud, in an environment where people sit for hours, six feet and a mask may not be enough protection. 


There are ways of reducing the risk of transmission further such as more air changes, diluting the indoor air, compartmentalization of space, and light sterilization. We will begin to discuss some ideas around this, as well as other simulated scenarios (unmasked sneeze, and unmasked talking (in progress)) in our next videos.

FAQ Regarding HOLT COVID-19 Simulations

We put together an FAQ that provides answers to the most commonly asked questions regarding our simulations. Click here to access it.

Let us know what you think of this, and if you’d like to hear more.

You can contact Steve Hugo, Principal at sh@holt.com or 607.273.7600.

Thank you!

PS – Here are two links that you may want to check out: HOLT’s YouTube channel showing more angles of the above simulations and photos of HOLT’s Ithaca office where the simulation was modeled.