RACA Journal March 2025 RACA_March2025_digital | Page 44

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Technical
and insufficient ventilation can lead to conditions like sick building syndrome , while inadequate thermal comfort and lighting can affect worker performance and well-being .
The discussion then shifted to various air purification and filtration technologies . LEEP explained that while air purification systems , including advanced filters and activated carbon filters , play a crucial role in improving indoor air quality , they also come with limitations . For instance , activated carbon filters have a limited lifespan and their efficiency can diminish quickly without continuous airflow .
Regarding ventilation standards , the current SANS regulation requires 7.5 litres of air per second per person . However , forthcoming updates are expected to increase this requirement to 10 litres per second per person . This change aims to enhance indoor air quality but will also demand more from HVAC systems , potentially increasing energy consumption and operational costs . One significant topic was the use of HEPA ( high efficiency particulate air ) filters , known for their high efficiency but also for their substantial pressure drop , which can increase system energy consumption . In contrast , the session introduced electrostatic filters as a promising alternative . Electrostatic filters , which charge particles to capture them more effectively , face efficiency issues once they become loaded with particulates . Despite this , they offer the advantage of reduced pressure drop compared to HEPA filters , making them a viable option for managing air quality with lower operational costs .
The presentation also highlighted advancements in UV-C technology . UV-C lamps , integrated into air handling units , are particularly effective at eliminating microbes , viruses , and bacteria . LEEP illustrated how UV-C light can be applied to heat exchanger coils and cooling coils to prevent the buildup of biofilms and maintain system efficiency . By breaking down biofilms , UV-C light helps improve airflow and overall performance of HVAC systems .
The discussion included a detailed explanation of ultraviolet ( UV ) light bands : UVA , UVB , and UVC . The UVC band , specifically around 254 nanometers , is noted for its germicidal properties , effectively disrupting the DNA ( deoxyribonucleic acid ) and RNA ( ribonucleic acid ) of microorganisms . This spectrum is critical for effective UV-C applications in air filtration systems .
Moreover , LEEP introduced electrostatic filter screens as a modern solution that combines the benefits of traditional filters with reduced pressure drop . These screens are designed to efficiently capture charged particles , including bacteria and viruses , while allowing for improved airflow . This technology can be integrated into existing air handling units to enhance air quality without significantly increasing energy consumption .
They overviewed the importance of integrating new technologies with conventional systems to ensure optimal indoor air quality . The advancements discussed , including electrostatic filters and UV-C lamps , represent significant steps forward in air purification , offering more efficient and effective solutions for maintaining healthy indoor environments .
A key point made was the importance of using quartz glass to protect UV-C lamps . The quartz glass acts as a shield against dust and other particles , ensuring that the UV-C lamp remains

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RACA Journal I March 2025 www . refrigerationandaircon . co . za