The Benefits of Humidity Control


Many factors go into designing an effective building control system, and many environmental influences that help guide the decisions made.

Too often, humidification is the last control measure considered, or the first measure removed when designing an environmental control solution. Perhaps because it is harder to perceive and quantify its value when compared with temperature, it can often be dismissed in the effort to reduce a budget.

While consideration of relative humidity’s impact on conditioned spaces is not always prioritized, maintaining relative humidity levels between 40 and 60% has been proven to provide many significant benefits. It contributes toward minimizing health threats, increasing wellness, increasing thermal comfort, and better managing energy usage in a facility.


Humidity plays a surprising role in the prevalence of airborne threats in a building. High humidity levels contribute to the growth and spread of certain threats like mold, bacteria, and VOCs. Low humidity levels increase the prevalence of pathogens like viruses, bacteria, and other allergens.

A significant aspect of the threat of airborne pathogens is the length of time that they can remain airborne. The smaller and lighter the particles, the longer they remain a threat. Viruses need low humidity to remain airborne and viable for extended periods. In dry air, viruses remain small and light and develop a protective crust around them which allows them to remain dormant for long periods while waiting for a viable host. As humans breathe, these dormant viruses are inhaled, introduced to a moist environment, and reactivated. Human cells become infected, and the virus can spread.

In properly humidified air, the lifecycle of viruses is significantly shortened and the number of dormant airborne viral threats is reduced.

During the summer months, high humidity becomes a problem. Prolonged exposure to high humidity levels can create breeding grounds for bacteria, fungi, and can increase additional viral threats. Elevated humidity levels can also promote emissions of VOCs from materials in a building. Maintaining optimal humidity levels removes the environmental influences which allow many of these threats to persist, and helps improve indoor air quality.


Health threats are constantly present, and even the best disinfecting processes will not remove 100% of the threats present in any environment. As building environment control specialists, we make every effort to eliminate threats and create environments where the growth of ongoing threats is diminished or eliminated, but because of the multitude of factors that can contribute toward the creation and spread of environmental threats, there will always be the potential for exposure to a health threat in any building.

Since threats cannot be 100% eliminated, and wearing personal protective equipment (PPE) at all times is not a viable long term option, the last line of defense is our body’s natural ability to combat potential threats. Many factors can influence the human body’s ability to combat threats. The majority of those factors can only be controlled or influenced by the individual. There are, however, environmental influences that are within our control, and can contribute toward enhancing a body’s ability to fight threats. Relative humidity levels are a key influencer that can be controlled.

Proper humidity levels allow the human body to remain better hydrated and respond to threats more effectively. The human body develops a natural barrier to bacterial and viral threats in the lungs as long as the ambient air provides enough moisture for the body to retain its proper hydration levels. Low humidity draws more moisture from our bodies and lungs and diminishes its ability to combat threats.

It is not just low humidity levels that diminish the body’s ability to fight off threats. The ability of the human body to combat threats is also impacted by the number of threats present in the environment. High humidity levels can create higher densities of airborne threats which can overwhelm our natural defenses and cause illnesses.

Maintaining 40-60% relative humidity provides an ideal environment for the human body to combat threats while minimizing the number of potential threats present in an indoor environment.


Maintaining optimal humidity levels in a building isn’t simply about reducing potential health threats. The human body also feels better in humidity levels between 40 and 60%. There are physiological benefits to maintaining optimal humidity levels that not only help us combat threats but which improve our mood and can drive increased productivity levels.

Some of the physical impacts of low humidity are dry noses, sore throats, sore eyes, headaches, and irritated skin. As we consider the impact of productivity on the bottom line of a business, it is important to consider not just the significant productivity losses due to illness, but soft losses due to discomfort and irritations. Eye soreness and itchiness can lead to screen fatigue and the need for more regular breaks from daily responsibilities. Sore throats and headaches can cause more frequent breaks and unplanned absences as occupants respond to symptoms of sicknesses brought on by nothing more than dry air.

Maintaining the relative humidity between 40-60% also helps the human body better absorb and transfer oxygen into the blood supply. This reduces fatigue, increases concentration, and allows building occupants to remain more productive for longer periods. Greater productivity not only contributes toward an improved bottom line for an organization, but it also increases the overall sense of wellness among building occupants which can help reduce attrition in an organization.

Properly humidifying the building environment allows occupants to experience fewer physical irritations, reduces illness symptoms, and helps them remain more attentive throughout their day. Health issues and absenteeism is reduced, and general wellness among building occupants is increased.


The perception of thermal comfort is impacted by humidity levels in the environment. Low humidity in cold air gives the impression that temperatures are lower than they are. Conversely, High humidity in warm air gives the impression that temperatures are warmer than they truly are.

Providing increased humidity during cold months can create the perception that lower building temperatures are more comfortable. Decreased building humidity during warm, humid months also provides the perception of greater thermal comfort at higher building temperatures. Thermal comfort is a significant contributor to occupant productivity. Fewer complaints due to thermal comfort mean fewer distractions throughout the day for building occupants, and fewer questionable issues for the maintenance staff to address.

The ability to influence thermal comfort allows facility operators to maintain higher building temperatures in the summer and lower temperatures in the winter without negatively impacting the thermal comfort of occupants. These temperature adjustments contribute to reductions in energy use by the temperature control equipment. They also increase the lifecycle of the HVAC equipment by reducing their ongoing demand.

While humidity control may not be a top priority when designing a building, there are many benefits to maintaining optimal relative humidity levels. Humidity Control can improve the indoor air quality in a building, improve the health and wellness of building occupants, and improve the energy usage and equipment lifecycle in a building.

As you proceed with your next building construction or renovation project, consider how humidity control can help contribute toward your health, wellness, safety, and operational efficiency goals.

Contact CM3 today to discuss how we can help you integrate humidity control into your next project, and help you achieve your goals.