New Delhi, Sept. 11 -- During a recent webinar on the importance of indoor air quality in the times of covid-19, Liam Bates, founder of air quality monitoring and solutions company Kaiterra, summed up the current conundrum when it comes to air-conditioning systems. "HVAC (heating, ventilation and air conditioning) is like a double-edged sword. It can be your best friend or it can be your worst enemy," Bates said. "The key here is ventilation." If your building's HVAC unit takes the air from a room, cools it down or heats it up, and then mixes it with a little amount of outside air before redistributing it, that is not great news. If it follows the same process, but mixes a substantial amount of outside air and then passes the air flow throu...