New Delhi: In a bid to contain the spread of coronavirus, the Centre on Saturday asked everyone to maintain AC temperatures between 24 and 30 degrees Celsius, and relative humidity between 40 and 70 per cent.
The Indian Society of Heating, Refrigerating and Air Conditioner Engineers (ISHRAE) said that re-circulation of cool air by room ACs “must be accompanied by outdoor air intake through slightly open windows and exhaust by natural exfiltration”, implying that this can be done more effectively in room air conditioners than central AC systems.
In low humid places, the humidity can be maintained at 40 per cent minimum with a water-filled pan in the room, the guideline said.
“In humid climates, set temperature closer to 24°C for de-humidification and in dry climates, closer to or at 30°C and use fans to increase air movement.”
Air filters should be cleaned periodically. Buildings that don’t have enough fresh air, should be provided with an additional fresh air duct. The guidelines also highlighted the need to sanitize air-conditioned spaces that have remained closed during the lockdown. There could be fungus and molds in ducts, it said.
A study in China indicated that the coronavirus tends to thrive in low temperatures (7-8 degrees Celcius) and its survival reduces progressively from 20 to 30 degrees. The SARS-COV-2 virus survived 14 days at 4 degrees Celcius on a surface while it died in 24 hours at 37 degrees Celcius and 30 minutes at 56 degrees Celcius.
Evaporative coolers should have clean and disinfected water tanks and placed at a window to draw in fresh air, the guideline noted. Windows should be kept open while using these coolers as the cooling reduces with increase in humidity levels inside the room.
ISHRAE also recommended using exhaust fans in kitchens and bathrooms.
