In the past year, the global COVID-19 pandemic has evolved from a short-term emergency requiring quick measures to a long-term crisis that will have implications for years to come. Across the globe, building managers are turning a critical eye on the quality of indoor air supply. What can be done to create indoor spaces that support occupants’ health and wellbeing? The answer can be a combination of innovation and the tried and true.

The power of light to disinfect

Along with measures like traditional chemical cleaning, reducing building occupancy, and behaviours like better hand hygiene, UV-C disinfection is playing an increasingly important role in keeping our spaces safe and healthy.

It may be entering popular awareness for the first time now, but UV-C is not a new technology – in fact, it has been used as a safe and effective disinfectant for more than 40 years.

It is also very well adapted for the threats of today. UV-C disinfection lighting is a proven and effective way to inactivate viruses, including SARS-CoV-2, the virus that causes COVID-19. In a laboratory test, Signify’s Philips UV-C disinfection upper air wall mounted luminaires inactivated 99.99% of SARS-COV-2 in the air of a room within 10 minutes. At 20 minutes, the virus was below detectable levels.

This same technology can be applied in multiple ways, from disinfection carts that can be moved around a building, to self-contained chambers that quickly disinfect small objects. And on the widest end of the scale, UV-C can be deployed within an existing HVAC setup to keep a building’s cooling systems free from biofilm and contaminants that affect both indoor air quality and the efficacy of the system.

Cleaner and more efficient

Quality of air entering the building through the Air Handling Unit (AHU) can have significant health and safety implications. The cooling coil’s dark, moist environment is particularly susceptible to the buildup of mold, bacteria and their by-products. When the cooling coil is dirty, the system recirculates microorganisms, spores and endotoxins produced by the molds along with the cooled air. High-output UV-C lamps cover the entire cooling coil surface, preventing the accumulation of bacteria and mold that could otherwise pass into the air supply.

This approach not only improves the indoor air quality, but also keeps the cooling coil working at maximum efficiency. While this is an area of continued research, trade estimates suggest that a clean cooling coil can lead to a 3-6% improvement in airflow and heat exchange. UV-C also has advantages over traditional cleaning methods. Costly specialist maintenance can be kept to a minimum, and there is a reduced need for mechanical cleaning that can degrade surfaces over time, or the use of chemicals that can contaminate groundwater and produce vapours that go on to enter the building’s air supply.

UV-C disinfection improves indoor air quality and keeps cooling systems running at their best

A one-stop-shop

Signify, the world leader in lighting, has increased UV-C manufacturing capacity as part of its response to the COVID-19 pandemic. We are now able to offer a full UV-C system that includes UV-C lamp, electronic ballasts, control panel along with all mounting and wiring arrangements that can be easily retrofitted into existing AHUs. With the addition of a digital control panel, the UV-C disinfection system can integrate with building management systems and offer additional performance indicators like lamp failure alerts, replacement alerts and lamp life indicators. As a safety feature, the system can be integrated with the AHU door to avoid accidental exposure. These systems can scale from small office buildings right through to large office campuses and airports.

COVID-19 has alerted the world to the importance of air quality in our indoor spaces. This pandemic will pass, but these improvements can remain, if building owners choose to invest in the long-term systems that will keep their indoor spaces healthy and safe.


Sumit Padmakar Joshi is the CEO and MD of Signify – South Asia (Formerly known as Philips Lighting).

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