A cutting-edge synthetic grass can naturally cool itself by harnessing rainwater and utilizing capillary action to decrease surface temperatures, offering a more sustainable and secure option for urban sports venues.
In city parks and sports facilities, real grass has frequently been substituted with more robust synthetic grass, enabling extended and vigorous usage. Nevertheless, artificial grass comes with its own drawbacks, impacting individuals and urban centers alike. It reduces rainwater absorption into the soil and can attain dangerously high surface temperatures, exacerbating the urban heat island phenomenon.
Revolutionary Cooling Mechanism in Synthetic Grass
Researchers from the Netherlands have now designed synthetic grass incorporating an underground water retention and capillary watering system. This innovation, elucidated in a recent analysis featured in Frontiers in Sustainable Cities, presents a cooler, safer, and more sustainable alternative to traditional synthetic grass.
“Our research highlights that integrating an underground water storage and capillary watering system in synthetic grass fields can result in considerably lower surface temperatures compared to conventional synthetic grass fields,” stated lead author Dr. Marjolein van Huijgevoort, a hydrologist at KWR Water Research Institute. “By implementing circular on-site water management beneath the field, we achieve a notable evaporative cooling effect.”
Mitigating Heat on Synthetic Fields
The synthetic grass and subbase system feature an open water retention layer directly beneath the synthetic grass and shockpad. In this water stratum, rainfall is stored. This water retention setup includes cylinders that ferry the stored water back to the synthetic grass surface for evaporation.
“The interplay of evaporative cooling and capillary ascent is regulated by natural mechanisms and weather conditions, ensuring water evaporates solely when cooling is required,” elaborated van Huijgevoort.
Experiments and Outcomes
Typical synthetic grass can attain surface temperatures of up to 70°C on sunny days. These temperatures are elevated enough to cause burns and provoke heat-related illnesses, spanning from mild skin irritations to possibly life-threatening conditions like heat stroke.
In a field study carried out in Amsterdam, the scientists observed that after replacing conventional grass with the self-cooling variety, temperatures dropped significantly. On a particularly scorching day in June 2020, the cooled synthetic grass registered a surface temperature of 37°C – merely 1.7°C higher than real grass – while traditional synthetic grass surfaces reached 62.5°C.
Air temperatures above the sections also exhibited variations. “We noted lower air temperatures at 75cm above the cooled sections in comparison to conventional synthetic grass fields, particularly at nighttime,” van Huijgevoort mentioned. “This preliminary evidence suggests that the cooled sections contribute less to the urban heat island effect.”
Environmental and Operational Benefits
The cooling synthetic grass amalgamates the perks of synthetic and real grass: it is long-lasting, self-cooling, and fosters a healthy sports environment. It can also retain nearly as much rainwater as natural grass. The field’s rainwater retention capacity additionally diminishes stormwater runoff, aiding in urban flood mitigation. During dry spells, supplementary water can be directly introduced into the system, or it could be irrigated akin to real grass.
Economic and Investigational Aspects
Installation expenditures, albeit, might be twice as costly compared to traditional synthetic grass. The scientists recommended a comprehensive cost-benefit appraisal be conducted to ascertain the genuine value of the investment.
Further research is imperative to gauge how cooling synthetic grass might influence the local vicinity and urban centers at large. Delving into the turf’s benefits under diverse climates and with varying storage capacities, materials, and infills is also crucial to pinpoint the optimal configuration, the researchers emphasized.
Initial findings, nonetheless, are encouraging. “Urban residents, particularly children, are increasingly seeking sports and recreational facilities,” van Huijgevoort concluded. “Through this study, we spotlight the benefits of the subsurface water retention and capillary watering system sans the drawbacks associated with synthetic grass fields.”
Reference: “Climate adaptive solution for artificial turf in cities: integrated rainwater storage and evaporative cooling” by Marjolein H. J. van Huijgevoort, Dirk Gijsbert Cirkel and Joris G. W. F. Voeten, 23 May 2024, Frontiers in Sustainable Cities.
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