www . refrigerationandaircon . co . za RACA Journal I March 2025 43
Technical effective over time . They stressed that the choice of quartz glass is critical , as the wrong type can diminish the lamp ’ s irradiance , reducing its efficiency in killing pathogens . The effectiveness of UV-C light in killing viruses and bacteria is determined by the dosage , which is a product of UV irradiance and exposure time . The dosage required to inactivate various pathogens was discussed , referencing pre-coronavirus studies . For instance , while the dosage required to neutralise Legionella was the highest , at 0.01 minutes , the dosage for the coronavirus was 0.33 minutes .
A notable aspect of the talk was the A well-attended in person Tech Talk at Cape Town . emphasis on proper installation techniques for are prevalent , as it helps purify the air before it circulates
UV-C lamps . They advised against installing UV lamps exposed through the space . directly to the air stream . Instead , they should be enclosed in • Photo-hydro ionisation ( PHI ) is an advanced air purification quartz glass to protect against damage and ensure consistent technology developed in America that has met the strictest performance . The optimal placement of UV-C lamps is crucial for air quality guidelines in California . This technology involves effective disinfection ; they should be installed where air speed is a reaction between UV light and a specialized catalyst to lower to increase the contact time with the UV light . produce hydrogen peroxide . Similar to PCO , PHI mimics
They highlighted the benefits of precise UV-C lamp selection . natural processes to purify the air . The hydrogen peroxide
For environments requiring stringent cleanliness , such as generated helps break down pollutants , including viruses hospitals or clean rooms , careful selection and placement of and bacteria , into harmless molecules . PHI units are
UV lamps are necessary to ensure adequate coverage and compact and easy to install , making them a versatile option effectiveness . This involves calculating the distance between for various applications . lamps and their placement relative to the coils to ensure that all • Odour control solutions : Addressing persistent odours in areas are sufficiently exposed to UV-C light . commercial spaces , particularly in restrooms , is a common
Typically , UV-C lamps have a lifespan of between 8 000 to challenge for building managers and contractors . To
9 000 hours , depending on factors such as the cleanliness of combat this , portable odour control units are now available . the quartz glass and moisture levels in the environment . The These units , which can be installed near problem areas installation of a control box , similar to those used for LEDs , is like restroom doors , use UV lamps and airflow to eliminate recommended to manage and monitor the UV lamps effectively . unpleasant smells . The design of these units includes a small
• Photocatalytic Oxidation ( PCO ) is a technology that fan that draws air through the UV lamp , where odours are combines UV light with a catalyst to purify the air . neutralised . These systems are plug-and-play , making them
The process involves a reaction between UV light and easy to deploy without extensive modifications to existing a catalyst , producing hydrogen peroxide ( H₂O₂ ) as a infrastructure . They have been successfully implemented byproduct . Hydrogen peroxide , a natural element found in high-traffic areas , such as shopping malls , where they in Earth ' s atmosphere , is known for its disinfectant have significantly reduced odour complaints . In one case , properties . It breaks down into water and oxygen , installation led to a noticeable decrease in odours within the effectively neutralising air pollutants such as bacteria , first hour of operation , improving the overall environment viruses , mold , volatile organic compounds ( VOCs ), and for customers and staff . odours . PCO technology has been around for some time but is only now gaining traction in many regions . These advancements underscore a broader trend towards It involves placing a PCO unit in the air handling unit or smarter , more responsive air purification technologies that main air duct system . As air flows through the system , improve both system performance and occupant well-being . As the UV light reacts with the catalyst , creating hydrogen the industry continues to evolve , the adoption of these cuttingedge solutions will play a crucial role in creating healthier , more peroxide that cleans the air . This method is particularly effective in environments where pathogens or pollutants efficient built environments . RACA
www . refrigerationandaircon . co . za RACA Journal I March 2025 43