Evaporative cooling and mist-based systems are attracting attention in a diversity of applications, including providing thermal comfort for construction workers in hot ambient conditions
Current estimates of the outdoor cooling market in the countries that constitute the GCC (Gulf Cooperation Council) region place it as nudging toward USD 50 million. Indeed, outdoor cooling – which was regarded as an outlandish concept, given the fact that air, cooled by electro-mechanical means, would be dissipated by harsh hot winds blowing – has found a footing in the GCC region, thanks to growing awareness and innovations in technology, according to industry players. And mega-events, like the World EXPO 2020 in Dubai and the FIFA World Cup in Qatar in 2022, are providing additional opportunities for growth.
People enjoy being outdoors as a social necessity. Also, as prescribed by doctors, exposure to sunlight is necessary to maintain an optimum level of Vitamin D. The oppressive heat in the Gulf countries has traditionally proven to be a challenge. The situation is changing, though, with more and more cafeteria and pool bar owners and beach and landscaping projects installing outdoor cooling units to lure customers and visitors even in summer climes.
Evaporative cooler system and mist-based technology are commonly used in areas where conventional air conditioning approaches are viewed as unviable. Evaporative cooling is believed to have low energy consumption and operating expenses. It purportedly can be used for a bouquet of applications, including residential, commercial and industrial and, in best-case scenarios, offer 25 degrees cooling comfort and a cooling capacity of nearly 400 square meters.
A misting system, which makes use of nozzles or orifices to stream out micro-fine mist, is based on the flash evaporation process involving water and heat. It involves the spraying of diffused water into the air. Like evaporative cooling, it is believed to consume less energy and has lower operating expenses. Questions are raised, though, when it comes to using a mist-based system in restaurants. People have expressed concern that the spraying of water can lead to a proliferation of bacteria, which could be a matter of deep concern when it involves the serving and the eating of food. Another concern is that misting can lead to exposing people to the possibility of Legionnaire’s Disease. Purveyors of misting technology, though, vehemently disagree with the prevalent view, saying the technology is not at fault and that the problem is owing to poor quality of the products supplied by some vendors. A vendor following best practices, they argue, would ensure a water treatment and delivery mechanism that would meet international HSE standards.
The general belief is that the evaporative cooling and misting technologies have a use where traditional air conditioning systems are unviable. For the past 4-5 years, misting, in conjunction with adiabatic cooling, is being used in the GCC region to cool the air in a cost-effective manner in industrial settings. Yet another use is to provide thermal comfort to construction workers laboring away in the hot sun. This is true of the construction work involving the 2022 FIFA World Cup, in Qatar. The general belief is that as the construction deadlines for different World Cup-related projects get closer, the demand for outdoor cooling in construction sites will increase, keeping worker health and safety in mind.
Till the World Cup was moved to the winter, a key concern was how to cool the stadia and the fan zones. With FIFA moving the mega-tournament to winter, the concern has been mitigated. All the same, the technology is available, should the need arise, post World Cup, to conduct matches in summer or to hold concerts in outdoor areas and general entertainment performances in open-air theatres.
Typically, outdoor airstreams when blowing across expansive stadia projects can cause unanticipated temperature variations and high turbulence. Technology has evolved to deflect and minimise the invasion of the hot airstreams. Based on measurements taken on-field to ascertain wind-flow patterns and the aerodynamics in playing fields, it has reportedly become possible to erect systems that would shield the stadia by creating high-pressure regions that essentially act as barriers for the hot air streams. Many believe this system, if sufficiently tested and deployed, could lead to a paradigm shift in the way we interact with hot spaces in high-ambient countries.