HVAC SYST EM STRAT EG I ES F o r A i r b o r n e D i s e a s e s
E XECUT I VE SUMMARY
Suggested Solutions: Improvements can be made to HVAC equipment, controls programing and facility operations. The following options are discussed in more detail throughout this document.
Situation : The Transmission of airborne disease is a concern in commercial buildings. There are many uncertainties with the current Covid-19 pandemic which is not confirmed to be airborne yet. However, the World Health Organization continues to recommend airborne precautions for circumstances and settings according to risk assessment. Objective : To reduce the risk of transmitting airborne diseases from infected individuals who may or may not have symptoms through specific modifications to both the operation of and equipment for HVAC.
• Increased Ventilation • Air Filtration • Air Disinfection (UVGI) • Temperature & Humidity Control • Air Direction & Space Pressurization Control • Restroom Exhaust Control
• Sequence of Operations Updates • Facility Operations & Maintenance
Conclusion: These recommendations should be followed based on building risk assessment, and in conjunction with the Building Pandemic Management Plan. Impacts of these suggestions on the occupant comfort, building pressure control, energy usage and other systems should be considered and analyzed before implementation.
H V A C S Y S T E M S T R A T E G I E S F o r A i r b o r n e D i s e a s e s
AIRBORNE DISEASES AND COVID -19
• Large droplets (around 100 m) released from an infected person
will not move further than 2 meters (6.5 feet).
• “Droplet nuclei” is less than 5 m in diameter and small enough to
be transported by air motion, including HVAC systems.
• It is known that the main routes of Covid-19 transmission are
through droplets and physical contact.
• It has not been confirmed if the virus transmits through small
airborne particles and aerosols. However there has been a case in
a restaurant where the HVAC system is in question.* There is also
a study on the aerodynamic analysis of the virus suggesting that
Sars-CoV-2 can be airborne and aerosol concentration is relatively