Performance is continuing to monitor the ever-changing circumstances of the coronavirus (COVID-19). The health and welfare of our customers and the occupants of their buildings remain a top priority.
We are making some recommended changes during this unique time in our country’s history. At a time when we all feel a bit powerless to deal with the current Coronavirus pandemic, building owners and operators are actually in a position to take steps to help prevent the spread of this serious infection.
According to experts, one of the most important things that can be done to support a healthy indoor environment and help protect against the spread of flu viruses like COVID-19 is:
Increase the volume of outside air (OSA) to achieve more air changes
HVAC systems are the source of fresh outside air for occupants. Increasing the amount of OSA reduces the amount of recirculated air through the HVAC system. “Ventilation represents a primary infectious disease control strategy through dilution of room air around a source and removal of infectious agents (CDC 2005)." Replacing contaminated indoor air with fresh OSA is an important step in improving occupant health. ASHRAE is the organization that sets the standards for the HVAC industry. It’s most recent advisory guidelines state that now is NOT the time for energy saving techniques like demand control ventilation (DCV) that reduces the amount of OSA.
We recommend increasing outside air levels to at least 20% -50% of the air handling capacity of the HVAC unit where possible. The mild temperatures of spring reduce the energy penalty that this action would otherwise create under more extreme summer or winter outdoor temperatures. Units equipped with the CATALYST can cost-effectively accommodate an increase in ventilation rates.
Demand Control Ventilation (DCV) is normally encouraged by the codes as a mechanism for reducing the energy penalty that results from “over-ventilating” commercial facilities. DCV is included in the CATALYST upgrade of RTUs. It reduces the volume of outside air typically to about 5% of the air handling capacity of the unit. A CO2 sensor is used to detect increases in human occupancy. When CO2 levels increase, the CATALYST logic opens the outside air damper further to provide more outside air.
In light of the ASHRAE guidelines which were just reaffirmed last February, we believe it is wise to increase the minimum outside air volume to assist in reducing the opportunity for airborne transmission of the coronavirus, at least until this pandemic is under control.
Upgrade air filters
High-performance filters (MERV 14-16) can remove particulates down to the size of the COVID-19 virus. Filters come in a variety of ratings. As their rating increases, so does the price. Standard pleated air filters entrap larger particles and are sufficient for most purposes, but they cannot scrub the air of bacteria and viruses. Improved filtration may be worth the investment when concerns about viral transmission are high as they are today. Supply of these filters are limited.
Maintain proper indoor relative humidity (50% RH)
Viral transmission occurs at higher rates when indoor humidity levels are either very low or very high. Studies have shown higher person-to-person transmission levels occur when indoor humidity is lower than 40% RH than occur at 50% RH. This has to do with the evaporation process. In the Seattle area, the average annual outdoor humidity is 79% RH. This is typically much higher than the indoor humidity level. Increasing the reliance on outside air can help increase the humidity in commercial buildings to an optimum level to help inhibit airborne transmission of viruses.
Another consideration is whether changes in the occupancy schedules for your facilities are in order. Many retailers are closed. Various sections of the country have been ordered to work from home or “shelter in place”. This results in closed dining rooms or empty offices, churches, manufacturing facilities, etc. It may be appropriate to make changes in your thermostats or BMS controls to address the actual needs of your facilities.
If you have the Transformative Wave eIQ Platform or Cobalt controls, we can most likely make changes to your outside air settings remotely. If the CATALYST was installed on your HVAC equipment, we can increase the minimum outside air percentage up to 40% without increasing the fan energy cost. If you have standalone (non-connected) applications of the CATALYST, adjustments to the minimum OSA percentage can be modified locally.
IMPORTANT: It is critical that your HVAC assets are in proper working condition and supply fans run continuously whenever the building is occupied. Commercial buildings, retail locations, restaurants, and places of assembly should never run supply fans intermittently or in the “auto” mode (unless steps are taken to periodically “over-ventilate” the building).
It is common for retail and small offices to run fans improperly. Make sure to educate your facility teams and service providers on the importance of running fans continuously. It is established in the building codes and national health standards. Failing to properly ventilate your facilities can have consequences to occupants and potentially create liability to the enterprise. We have long advocated for this and our technologies are designed to cost-effectively allow operators to comply with ventilation standards and still save energy.
Health concerns and fears abound right now. Hopefully soon, employees and customers will be returning, and our facilities will be full again. It can be reassuring to building occupants to learn that you are taking steps to create the healthiest indoor environment possible for them.
We are here to serve you at all times, but particularly during this serious time for our nation.
Here are a few helpful resources related to the topics above:
- CDC: Interim Guidance for Businesses and Employers to Plan and Respond to Coronavirus Disease 2019 (COVID-19)
- ASHRAE: Position Document on Airborne Infectious Diseases (reaffirmed February 2020)