May 3, 2021 Improving Commercial Indoor Air Quality
As more businesses welcome employees back to the office, commercial indoor air quality is of high concern. To address these concerns and help maintain a healthy environment, building owners can implement several HVAC system modifications and green building design strategies.
HVAC Modifications Can Help Protect a Building’s Occupants
Even before COVID-19, the negative effects of poor indoor air quality were vastly documented. In fact, the EPA states that indoor air can be 2 to 5 times more polluted than outdoor air. So, it comes as no surprise that many individuals are even more concerned about the quality of air in their workspace.
The challenge of improving indoor spaces over the past year has prompted a range of approaches. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), “changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.”
Although all buildings require different measures, HVAC modifications, in combination with other safety strategies, can go a long way toward protecting a building’s occupants from infectious disease. Here are 5 general recommendations to help improve commercial indoor air quality.
1. Increase Air Filtration To Meet MERV Requirements
Upgrading and replacing air filters is a cost-effective strategy to implement first. The MERV (Minimum Efficiency Reporting Value) scale defines the ability of filters to trap particles. The higher a MERV rating is, the more particles that filter can capture.
ASHRAE Standards 62.1 and 62.2, Ventilation for Acceptable Indoor Air Quality, requires that filters in HVAC systems meet a minimum rating of MERV 13, but a MERV 14 (or better) filter is preferred.
2. Implement Maintenance Checks
In addition to implementing appropriate air filtration, proper cleaning and maintenance of air handling systems is also a critical step to improve air quality. If you are only doing annual or semi-annual inspections, consider adding a more frequent maintenance interval. Remember to consider PPE when maintaining ventilation materials, including filters and condensate. ASHRAE recommends that all building owners and service professionals follow the requirements of ASHRAE Standard 180-2018 “Standard Practice for the Inspection and Maintenance of Commercial HVAC Systems” which has tables to show the typical maintenance on equipment that has been in operation.
3. Improve Air Exchange Rate
Another strategy that can help reduce the spread of contaminants indoors is through increasing the building’s air exchange rate. When evaluating the amount of outside air, the more fresh air, the better. When increasing outside air, it’s important to also keep exhaust and relief air systems as designed.
ASHRAE provides the following as a pre- or post- occupancy flushing strategy, “Flush the spaces for a duration sufficient to reduce concentration of airborne infectious particles by 95%. For a well-mixed space, this would require 3 changes of space volume using outdoor air (or equivalent outdoor air including the effect of filtration and air cleaners) as detailed in the calculation methodology.”
But, how do you know if the building has enough fresh air circulation? CO2 sensors can be a helpful tool to measure the amount of CO2 levels in an indoor environment.
4. Maintain Humidity Levels Between 40%-60%
Relative humidity can have a large impact on the ability of pathogens to spread in an indoor environment. Research indicates that maintaining relative humidity between 40% and 60% decreases the bio-burden of infectious particles in the space and decreases the infectivity of many viruses in the air. However, hot and humid climates may struggle to keep their space below acceptable temperature and relative humidity for comfort. And, cold climates may struggle to keep the space above acceptable space temperature and relative humidity for comfort. Consider adjusting the space comfort setpoints to increase the system’s ability to use more outside air.
5. Utilize Ultraviolet Light Germicidal Irradiation and Other Emerging Technologies
UV germicidal irradiation (UVGI) can be used as a supplemental strategy in effort to inactivate airborne viruses in indoor commercial spaces. Ultraviolet C (UVC) provides the most germicidal effect. Although the CDC and ASHRAE do not have a position for or against UVGI, some research shows that this form of ultraviolet light can effectively inactivate >95% of aerosolized influenza viruses.
Improve The Indoor Air Quality at Your Facility
The rapid spread of SARS-CoV-2 forced many corporate entities, government buildings, universities, health care facilities, and other commercial building owners to take the necessary steps to reduce the potential for indoor transmission.
Considering most efforts to improve air quality involve modifications to HVAC systems, it’s important that the changes must also coordinate with building services, electrical systems and other structural elements. Therefore, it is vital to ensure that renovations and new construction utilize the services of an experienced and trusted MEP engineering company, like KMB.
Get the right solution for your building. Our internal team can evaluate your current systems and provide recommendations to enhance your facility’s air quality and lower the potential for airborne transmission.
Read More: Mechanical and Energy Engineering Strategies to Improving HVAC Efficiency>>