RACA Journal August 2020 | Page 56

Industry matters INDOOR AIR QUALITY Mousa says that the design and operation of HVAC systems can hinder disease transmission in several ways. HVAC systems supply clean air to susceptible occupants, such as in crowded and closed spaces, thereby helping in reducing the possibility of disease transmission. Johnson Controls offers a complete range of advanced solutions and technologies covering filtration, proper humidification and ultraviolet air purifiers that reduce airborne contaminants to achieve an optimum room temperature and humidity, and a cleaner and healthier IAQ. Air handling units (AHU) show how HVAC units can play an important role in reaching the required levels of IAQ and beyond. These HVAC units supply 100% fresh air by containing contaminated air and exhausting it to the outdoors, and then replacing it with well-treated fresh air, which re-enters the space after a rigorous filtration process; this process cleans the air within the space/room. Air filtration starts with the prefiltration stage to prevent dust particles from passing through air. Some units in the market are equipped with filters that do not allow the passage of big particles to the air-conditioned environment through multiple stages of filtration that can achieve up to 95% filtration efficiency in comfort application, and 99.95% in medical application, thereby increasing the IAQ depending on the application. Another technology applied in the HVAC air side systems is the ultraviolet lights (UV). These lights can help enhance the IAQ as well as eliminate many types of fungi, bacteria, germs, viruses and pathogens. Typically, the UV lights are installed within the air handler, which remains turned on 24/7. The HVAC UV lights are effective at controlling mould growth inside the air handler, as all mould in the line-of-sight of the UV bulb is killed, keeping the coil mould-free. MAINTENANCE IS VITAL Using the right procedure for the maintenance of the equipment has a huge impact in eliminating any potential microbial growth in the HVAC unit and the air delivered by it. Performing preventive maintenance procedures, such as cleaning surfaces, filters and cooling coils, at regular intervals, is key to maintaining decent indoor air quality. RACA