Combating COVID-19 Airborne Transmission with Intelligent HVAC Simulations

By Boris Marovic

This year has been a challenge for all of us and as mentioned in my blog in March about “What Engineers Can Do About COVID-19”, one of our customers is working hard on helping people to face this challenging time. This major HVAC system manufacturer is looking into ways of bringing people back to work, making re-opening schools and restaurants possible again.

Although vaccines had received FDA approval, it will take probably several months for everyone to be vaccinated and things getting back to normal. And even then traveling might be still challenging, especially to other countries as we know from many other diseases that there will be pockets in the world where medical care is not as well established. Not to mention any mutated strain of the virus that might be immune to the vaccines or is more dangerous. Such circumstances will require a continued higher alert for some time. We still know too little about the virus to become careless.

But I think everyone can agree, we need to get the economy and public life going again. People need to be able to be safe at their workplace, when shopping for clothes or groceries, and students need to be able to participate at classes again. Our customer is now working with a cloud solution driven by Mendix, to be able to automate HVAC and Ultra Violet Germicidal Irradiation (UVGI) simulations with Simcenter FLOEFD and optimize the positioning of HVAC ducts and UV lights intelligently with the help of Simcenter HEEDS, as other solutions to reduce the virus spread are also being developed.

You might be wondering why optimization of some lights and air vents is so important. Well, every room is different in size and layout. Therefore the same location of the vents and UV lights that might have the best performance in the one room might be causing a bad airflow in another room or not allow for efficient irradiation with the sterilizing UV lights. Some rooms need special treatments after they’ve been used, such as in hospitals and doctor’s offices.

I think we all heard about good venting of the room is important, however, recirculating HVAC systems can be dangerous when the contaminants are only recirculated with the air over and over and potentially spread the virus throughout the indoor space. UVGI is used to kill off germs, viruses and other harmful biological pathogens. Bringing UV lamps into HVAC systems helps to kill off these pathogens and allows for the air to be recirculated safely. But the UVGI efficiency is important as these pathogens have to be exposed for a certain duration with a certain irradiation dose. So simply putting some UV light somewhere is not having the right effect.

A UV lamp position optimization study in hospital room.

Simcenter FLOEFD simulations can help to optimize the UVGI efficiency in rooms by playing with the position of the UV lamp. Running tens of simulations varying the position with the help of Simcenter HEEDS, which uses a proprietary algorithm to intelligently optimizing the position.
The video shows such a model setup with wide coordinate ranges for the 3 UV lamps at the 3 walls. Simcenter HEEDS is then moving them around from simulation to simulation and is searching for the optimum location at these walls that reaches the highest UVGI efficiency.

This optimization can be run with multiple parameters. Mendix can be used quickly and easily to create a web or app interface with its low coding capability, for the customers to define rough criteria such as room dimensions, number of occupants, and other parameters needed for the simulation. Simulation tasks are automatically controlled by Simcenter HEEDS and provide potential solutions back to the customer via their mobile device.

Such a service, provided by our customer to his clients, can help schools, companies and other institutions to allow for a safe way to get back to normal operation faster and safer.

If you like to know more, feel free to contact us and if you are based in the US, feel free to contact my colleague Ted Lin and let us help also you to improve your products and services in this difficult time.

Also I would like to thank Adil Ali who created the Simulation of the hospital room in the video.

This article first appeared on the Siemens Digital Industries Software blog at