Indoor air quality (IAQ) has become a hot topic lately and as we move closer to a potential return to the workplace, guidelines have been put in place to ensure a safe and healthy environment for occupants. Based on re-entry recommendations from the Federation of European Heating, Ventilation and Air Conditioning Associations (REHVA) and The Chartered Institution of Building Services Engineers (CIBSE), we have put together operational guidelines to assist facility managers and building owners in remaining compliant with IAQ requirements.
Create and monitor re-entry schedules
REHVA guidelines recommend setting ventilation equipment to reach optimal speed 2 hours before occupancy and remain running at optimal speed 2 hours after. At night and during weekends, it is recommended not to switch ventilation off but to keep it running at a slower speed. Exhaust ventilation systems of toilets on the other hand should always be kept on 24/7.
Ventilation: Switch AHUs to 100% fresh air
Many AHUs utilize air recirculation features to improve energy efficiency. Re-entry guidelines recommend disabling this feature as contaminated air can be recirculated.
In order for the AHU to utilize 100% fresh air, any air recirculation needs to be disabled by closing the mixing damper in the AHU. Since the mixer damper is opened or closed based on the CO2 levels of the return air, using a lower value for the CO2 setpoint will ensure that the mixing damper in the AHU will remain closed and return air will not be recirculated.
Use window airing
It is strongly recommended to avoid crowded and poorly ventilated spaces. In the case of buildings with no mechanical ventilation systems, using operable windows is essential to boost air exchange and should be applied even when it causes thermal discomfort. Window airing is also recommended for buildings with mechanical ventilation systems as it further boosts ventilation. However, open windows in toilets should be avoided to assure the right direction of ventilation.
Under some circumstances, air-borne contaminants in extracted air can re-enter the facility. Heat recovery systems may transfer air-borne contaminants from the exhaust air side to the supply air side via leaks.
That is why it is important to manually inspect heat recovery systems to ensure there is not much leakage between return air and supply air – especially thermal wheels which are most likely to have leakages. Also, guidelines suggest replacing filters regularly and performing maintenance work with common protective measures including respiratory protection. Alerts can be set up in the Envio platform to inform maintenance workers when filters need replacing or about malfunctioning ventilation equipment.
To stay compliant with the industry standards, facility managers have to monitor their own indoor air quality at all times. This can be overwhelming and time-consuming. Envio’s remote monitoring solution offers facilities managers a simple and affordable monitoring solution to ensure they are meeting regulatory compliance while operating at peak efficiency. Our solution offers remote control while seamlessly integrating with several third-party air quality sensors to measure key IAQ metrics and integrate them with occupancy, alerts, and alarms, and more so users can have an unmatched level of real-time information at their fingertips.
Contact us for more information.