Amid public concerns associated with air conditioning, ventilation and the spread of coronavirus, the government has issued guidelines compiled by the Indian Society of Heating Refrigerating and Air Conditioner Engineers (ISHRAE).

The ISHRAE guidelines on the use of air conditioners at homes and workplaces were shared by the Central Public Works Department (CPWD).

As per the guidelines, it is ideal to operate the air-conditioner between 24-30 degree centigrade at home amid the coronavirus pandemic. The humidity levels must be maintained between 40-70% and rooms must be well-ventilated.

“The best action to limit risk of COVID-19 infection by air is to ventilate indoor environments with outdoor air as much as possible. Mechanical ventilation systems and air conditioning systems, which provide ventilation, can perform this function more effectively than simply opening the windows, because they improve the quality of the outdoor air with filtration,” ISHRAE guidelines read.

Here’s what the guidelines suggest:

For homes

It is suggested to keep rooms ventilated when the AC is not running, too much humidity should be avoided.

“Too much humidity leads to higher levels of dust mites and fungi, two of the worst culprits for indoor allergy sufferers. Mold and fungi are known to exacerbate respiratory conditions such as asthma,” the statement read.

In the case of ceiling fans, they should be operated with windows kept partly open. “If an exhaust fan is located at a nearby location then it must be kept running to exhaust air for better ventilation.”

“Evaporative coolers must draw air from outside to ensure good ventilation,” the document read.

For commercial, industrial facilities

Ventilation with outdoor air is suggested as much as possible. “The mechanical exhaust air shall be 70-80 percent of the fresh air quantity to maintain necessary positive pressure in the space,” the document read.

Amid the lockdown, most commercial establishments have remained shut and will require maintenance. In such a scenario, the air-conditioned spaces of locked down establishments will pose health hazards.

It states that fungus and molds could develop 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. The system not be designed for sufficient fresh air intake and ventilation.,” the release stated.

The document was prepared by a Covid-19 taskforce set up by ISHRAE comprising experts, academics, manufacturers and people related to sciences such as filtration, healthcare facility design, and indoor air quality safety.

The guidelines were formed after examining and analysing information pertaining to the climatic regions of the Indian Subcontinent.