Ratchaprasong Square Trade Association (RSTA), Research & Innovation for Sustainability Center (RISC), and Dees Supreme are protecting Ratchaprasong with FAHSAI Mini, a city-level air purifier developed by RISC to tackle air pollution and toxic dust.
Air pollution and PM2.5 have become more severe in 2025. The crisis is set to last almost the entire year. Air pollution in Bangkok and many Thai provinces is among the world’s worst. This dust affects daily life and can cause long-term health problems such as chronic obstructive pulmonary disease, lung cancer, asthma, cardiovascular disease, and heart failure.
Mr. Chai Srivikorn, President of RSTA, said: “RSTA is aware of the problem and is committed to working together to create a good environment for people who live and work in the heart of Ratchaprasong. We’re concerned about air pollution’s impact on health and especially PM2.5, which has become more severe in recent years.
“We’ve worked with expert partners in technology and innovation. Research & Innovation for Sustainability Center (RISC) by MQDC and Dees Supreme have piloted the installation of FAHSAI Mini air-purifier towers in key areas of Ratchaprasong to help reduce dust and air pollution.
“We believe this collaboration will help set a new standard for improving urban air quality and promote Ratchaprasong as a safe and livable area for everyone of all ages, both Thais and tourists from around the world. The Ratchaprasong district attracts over 500,000 visitors daily, reinforcing its position as a prime commercial hub. The Ratchaprasong Walk (R-Walk) skywalk has a usual average foot traffic of 80,000 – 100,000 people per day, but during the festive season, it peaks at 100,000 – 150,000 people per day.”
Mr. Chai Srivikorn, President of RSTA
RSTA looked for innovative technologies for clean and safe air at the Ratchaprasong intersection in front of Gaysorn Village and Gaysorn Amarin. Many Thais and foreigners visit these tourist attractions, especially in the morning and evening.
FAHSAI Mini is an innovative urban air purification tower by RISC, which has researched and developed several city air purifiers. FAHSAI Mini can be used outside buildings to effectively reduce small dust particles such as PM2.5.
RISC has been researching in various fields since 2019 to find technology to remove PM2.5 and achieve safe air, said Assoc. Prof. Dr. Singh Intrachooto, Chief Executive Officer of RISC.
FAHSAI air purifiers use jet venturi scrubbers. A fan draws in air that then goes through a 2-layer high-speed water spray nozzle and a dust-trapping structure. By raising the water’s surface tension, the system can capture particles as small as 0.3 microns. A UVGI system sterilizes the air. The cleaned air is released at a breathable height and the desired volume as driven by the fan.
The device uses only 50 liters of water each day to remove dust and airborne contaminants. A water circulation system allows some to be reused. The water is sterilized with ozone technology and filtered.
FAHSAI Mini is RISC’s latest model and appropriately sized for Ratchaprasong. The air purifier cleans up to 60,000 cubic meters of air each hour. The device protects an area about 50 meters in radius, equivalent to a large football field, to a height of about 5 meters (about 12,500 cubic meters).
FAHSAI Mini’s efficiency has been constantly monitored and the device reduced dust by up to 60% in January.
“FAHSAI Mini can provide a model for Thailand to deal effectively with PM2.5,” said Dr. Singh. “We hope that the project will be expanded to other areas so people can breathe clean air and enjoy a better quality of life.”
Dees Supreme holds the patent for FAHSAI Mini and aims to further develop its commercial use as its official distributor.
FAHSAI Mini has been cleaning the air at Ratchaprasong since 14 February. The collaboration aims to tackle air pollution, including PM 2.5, and to improve the quality of life and respiratory health. Ratchaprasong continues to solidify its status as a premier landmark in Bangkok, further enhancing its image as a vibrant commercial district. This development reinforces its position as a dynamic hub that seamlessly caters to modern urban lifestyles, offering an exceptional blend of business, shopping, and lifestyle experiences.