In the last one decade, India has witnessed an increase in frequency as well intensity of Urban Heat Islands. This phenomenon is caused by converting natural ground surfaces such as bare soil, vegetation, water bodies , etc to build areas mainly composed of asphalt, cement, bitumen, concrete, brick, rock etc. These materials absorb a large portion of the incoming solar radiation and retain it for long periods thereby increasing the land surface temperature of the area. In cities, buildings with dark surfaces have lower reflecting capacity (thus lower albedo) , thereby absorbing more heat and causing temperature rise. The concentration of these built up areas and population in limited spaces have grave implications.
Urban Heat Islands(UHI) are known to exacerbate heat, deteriorate air and water quality, alter agriculture patterns, land use dynamics ultimately leading to resource crises in the future. Although our cities expand spatially and seem to take up a lot of land, only about 1% of the total global land surface is covered by built up areas.
India’s Census Report 2011 found approximately 30% of the population living in urban areas which is set to grow to 50% in the next decade. On top of that, already over urbanized spaces like Bengaluru, Hyderabad , Delhi, Kolkata are facing pressure of increasing demand for more built up areas to accommodate the rising population. The average UHI intensity for the past two decades in Bangalore and Hyderabad is found to be increasing at the rate of 0.040 °C and 0.033 ° C per year , respectively. Delhi’s Mungeshpur, located in the suburbs, breached the 50°C threshold for the first time in its history. Over 300 lives have been lost this summer due to heat related complications such as heat strokes, dehydration etc across the country. Moreover, the heat exacerbates air pollution levels, as rising temperatures contribute to the formation of ground level ozone, a potent greenhouse gas and harmful pollutant. Energy demands also spike up as a consequence, increased air conditioning requirements drive more electricity generation, more fossil fuel usage for running thermal power generation stations. Air conditioners themselves contribute to the UHI effect by releasing hot air into the environment thereby setting a vicious cycle in motion. According to a study by Resources for the Future, each 1°C increase in temperature raises energy demand by 0.5-5%, depending on the level of air conditioning penetration in the area.The rising temperatures also have a bearing on the economy: heat related stress causes worker exhaustion, directly hampering their productivity. According to the Lancet journal, India lost close to 164 billion work hours due to the UHI phenomenon.
Countering UHI effect in India requires a multi faceted approach. Greenery is a useful deterrent, through the use of urban forestry, green roofing etc. IISC suggests an ideal human to tree ratio to be 7 trees/ person , a stark contrast to the current reality in the majority of the cities. However, land use dynamics makes it difficult to plant trees in affected areas and trees usually have longer gestation periods to show its effects. Urban planning and building design needs to be prioritized for heat mitigation.Roofs comprise 20-25 percent of total surface in urban landscapes. In the immediate term, innovations like cool roofs and HRC Heat reflective coatings can play a critical role in combating UHI effects. A cool roof is one that reflects most of the incident sunlight and efficiently emits the absorbed solar heat back into the atmosphere, instead of conducting it to the building below. As a result the roof literally stays cooler, with lower surface temperature, keeping the building at a cooler and comfortable temperature with high Solar Reflective Index(SRI). A high SRI value of a coating indicates a high degree of cooling effect by acting as a shield for the roof allowing minimal solar penetration into the roof hence helps in saving energy.
SRI value incorporates both solar reflectance and thermal emissivity in a single value. SRI measures the roof’s ability to reject solar heat, defined such that a standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 100.
Innovative products like LuminX have been at the forefront of the battle against the UHI phenomenon.
Role of LuminX in countering UHI
LuminX is a water-based acrylic cross-linked elastomeric Cool roof coating. Its innovative advanced nanotechnology-based formulation offers high solar reflectivity and thermal emittance which significantly reduces the roof temperature even in the extreme weather conditions. LuminX works on the cool roof coating technology principle. Its high SRI value 111 ensures that it reflects the maximum amount of heat. Its unique formulation forms a strong chemical bond with the surface and offers complete protection with a promise to keep the building roof cool by up to 40% reduction in the roof temperature. The Solar reflective coating can be applied on a variety of installations ranging from residential homes to manufacturing industries, from sheds to public buildings in countering UHI’s effects. LuminX as a brand,has already made its footprint as a top rated product with > 1200 reviews on Amazon
Figure: LuminX coated cool roof for IGBC Green Building certification – Mumbai – Panvel – Residential Apartment project.
Figure: application of LuminX on a Garments Manufacturing Unit.
Why choose LuminX over others?
Choice of reputed brands and market leaders: the company strives to provide the best product in its category.
Economical: although a myriad of other options like green roofs, use of reflective tiles, creation of shades etc are available to counter UHI and its effects, LuminX provides the cheapest and most effective alternative. The cost incurred is less than Rs 25 per square feet of coating. This is more lucrative than any other solution in the market.
Longevity: the product has an average lifespan of more than 5 years, easily washable striving to add more value to customers for every penny spent. Product is resistant to dirt pickup, has crack bridging properties abilities to the roof surface.
Easy to apply : the product is a waste-based. It can be easily applied by oneself without requiring much expertise and has a Do it yourself ( DIY) feature.
Increased savings : it has been found to reduce electricity consumption by 20% during peak demand months by keeping the surface underneath the coat-cooler with reduced relative humidity and increased thermal comfort , thereby reducing Air Conditioner’s usage.
Ease of orders and supply: available on all leading e-commerce sites with pan India delivery options
Quality assurance:LuminX is tested as per ASTM and EN standards , certified by GRIHA council on meeting the specified norms. GRIHA is India’s national rating system for sustainable habitats.
