Jatin Sachdeva, GM, Au Pure IAQ Solutions

Dubai, UAE, 13 January 2019: Urban Heat Island (UHI) is a well-accepted phenomenon within city areas, especially in places with a high amount of concrete concentration per square km of area, said Jatin Sachdeva, General Manager, Au Pure IAQ Solutions. Elaborating, he said, “The compounding effect is the population density in such areas, which leads to a high cooling requirement.” In addition to high temperatures, the compounding effects of UHI also include reduced fresh air availability and also a high concentration of human generated contaminants, he said. “In order to mitigate the effect of UHI, one can use applications such as green roofs and reflective ceilings,” Sachdeva said. “It is imperative,” he added, “that the choice of HVAC systems have a balance between energy savings and occupant comfort.”

Pointing to a few suggestions on how the risks related to UHI can be averted, Sachdeva said there should be a special focus on increasing fresh air intake during cooler months to reduce cooling loads and ensure that contaminant levels are kept under check, much below the permissible levels. In addition, he said, “Employing systems like bi-polar ionisation (on the supply side) and UV systems (on the return side) to negate the contaminants and the circulation of air conditioned air also proves to be beneficial.” Speaking specifically with regard to negating UHI and maintaining good IAQ at events, such as the World Expo 2020, in Dubai, he said, “The World Expo 2020 is expected to see approximately 25 million visitors.” With regard to IAQ in the pavilions, he said, the effects of high occupancy in large buildings with exposure to high temperature and climate leads to additional body contaminants being generated, like perspiration and microbial contaminants, which impact a building significantly.

Elaborating, Sachdeva said, additional stressors such as light and noise play a crucial role in impacting occupant comfort within an occupied building. From a heating and ventilation perspective, he added, having proper acoustic balancing and a well-lit area helps in significantly enhancing occupant comfort. “One of the biggest challenges with reference to measuring IEQ,” he asserted, “is the absence of stressors like contaminants, noise and bad lighting.”

One of the main challenges with maintaining IAQ is that it is ‘invisible’ in nature and the ‘symptoms’ of bad IAQ are visible on its occupants, Sachdeva said. “Unless proactively measured,” he added, “IAQ is dependent on the proactive and inclusive approach of the operators and facility managers to ensure long-term air quality and comfort of the occupants.” A modular approach for HVAC design and scope for segmentation, paired with an additional air conditioning setup, he said, is crucial for the long-term availability of the buildings.