Reducing Airborne Pathogens with humidification

How can humidification keep people healthy in offices and schools?

Dry indoor air is linked to various health issues, such as dry skin, irritated eyes, and respiratory problems. In offices and schools, where shared spaces and frequent face-to-face interactions create ideal conditions for the spread of airborne viruses, maintaining proper humidity levels is crucial.

A pivotal study from 1986 established that the optimal conditions for human health fall within the 40-60% relative humidity (RH) range at normal room temperatures. This study continues to guide HVAC professionals and sets the standards for healthy built environments by organizations like the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE).

Maintaining relative humidity within the 40-60% RH range reduces the risk of virus transmission and enhances the comfort of building occupants. Adequately humidified spaces also increase productivity, improve concentration, and reduce fatigue.

What should schools and businesses do right now to help protect employees?

To ensure healthy humidity levels, the first step is to use an inexpensive hygrometer to measure relative humidity (RH). This quick assessment will reveal whether a facility is optimizing indoor air quality.

Supplementary humidification systems can be quickly installed on a wall and add moisture to rooms immediately. Larger humidification systems can be incorporated into a facility’s HVAC system, in the mechanical room, or on the roof, and keep an entire building humidified.

What technologies should they look for to be implemented in HVAC systems to avoid the threat of airborne illnesses and improve our ability to curb the spread of viruses?

While other protections like mask-wearing and hand sanitizer helped keep us healthy during the pandemic and the annual flu season, these methods rely on individual actions. However, indoor air quality can be improved with little day-to-day effort by making simple improvements to building HVAC systems that can significantly impact the health of all occupants. 

Air filters are commonly the first thing people consider when searching for a solution to improve indoor air quality. They are an excellent first line of defense and contribute to improving the air as it enters indoor spaces. However, they do not directly impact the air within a given space. This is where ensuring that indoor air is properly humidified becomes equally important.

Two types of humidification systems are used in commercial buildings – steam (isothermal) and evaporative (adiabatic). Steam humidifiers produce humidity by boiling water and releasing the steam into the air. Evaporative humidifiers operate on the principle of natural evaporation, using heat already present in the air to evaporate tiny water droplets dispersed by the system. 

While there is a short-term, day-to-day “set it and forget it” benefit to a commercial humidification system, there is also a long-term “get it and keep it” benefit, as the system can last up to 20 years. With health benefits beyond reducing the transmission of viruses, that long-term benefit delivers a valuable return on investment year after year.

Should the installation of these systems become a public health priority?

Installing advanced HVAC systems and technologies like commercial humidification systems should be considered a public health priority, especially in offices and schools where many people gather daily. Improving indoor air quality can help mitigate the spread of airborne viruses and reduce illness transmission. Investing in these systems as part of broader public health strategies to create safer and healthier indoor environments is crucial.