The Centre, in an advisory, said the ideal temperature to maintain an air conditioner during the COVID-19 pandemic was between 24-30 degree celsius, with a relative humidity between 40 and 70 per cent. "The conditioners must be accompanied by outdoor air intake through slightly open windows and exhaust," according to the advisory. "In dry climates, do not allow the relative humidity to fall below 40 per cent. Water evaporating from a pan kept in the room will increase humidity if it falls below 40 per cent."
The rooms should be well-ventilated and exhaust fans can be used for the purpose, according to the advisory. "The mechanical exhaust air shall be 70-80 percent of the fresh air quantity to maintain necessary positive pressure in the space," according to the advisory.
NDTV quoted the document: "Most commercial establishments have remained closed during the lockdown. These establishments will need maintenance for both engineering and health safety. The air-conditioned spaces of establishments under prolonged lockdown will pose health hazards due to fungus and molds in the ducts and open spaces depending on the humidity and temperature prevailing within. Further there may be bird droppings, and excreta of rodents as well increased level of insects."