<p>Whether we like it or not, air conditioners are here to stay. While they cool our homes and offices, air conditioners can also help in curbing the transmission of Covid-19 virus.</p>.<p>The size of a coronavirus particle is in the range of 80-160 nanometres, and can be transferred by infected microscopic airborne particles and contaminated aerosol droplets. In fact, high relative humidity, which implies higher moisture content in the air, has been found to slow down the effect of the virus. In such situations, the moisture settles down the particulate matter and does not provide the virus a nucleus to settle on and remain airborne for long.</p>.<p>The human body has excellent protection systems. The moisture in the air helps in trapping foreign particles in the nasal passage. In fact, research has shown that high relative humidity of 80% and above can significantly neutralise the Covid-19 virus. However, high humid conditions can be uncomfortable for most people if the ambient temperature is high.</p>.<p>Taking all this into consideration, the Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE) has recently issued guidelines that recommend setting the room temperature between 24°C and 30°C, while keeping the humidity level between 40% and 70%. It’s also recommended that natural or mechanical ventilation be provided to have good outside air inflow which helps in air changes which is critical in multi-occupant public spaces.</p>.<p>Air conditioning is categorised based on the types of indoor units installed: (these indoor units may be connected via refrigerant or chilled water pipes to the outdoor units. Thus, to limit risk of Covid-19 infection by air, ventilate indoor environments with outdoor air as much as possible. Mechanical ventilation systems and air conditioning systems are better as compared to opening the windows because they improve the quality of the outdoor air with constant filtration. </p>.<p><br /><em><span class="italic">(The author is executive secretary, ISHRAE)</span></em></p>
<p>Whether we like it or not, air conditioners are here to stay. While they cool our homes and offices, air conditioners can also help in curbing the transmission of Covid-19 virus.</p>.<p>The size of a coronavirus particle is in the range of 80-160 nanometres, and can be transferred by infected microscopic airborne particles and contaminated aerosol droplets. In fact, high relative humidity, which implies higher moisture content in the air, has been found to slow down the effect of the virus. In such situations, the moisture settles down the particulate matter and does not provide the virus a nucleus to settle on and remain airborne for long.</p>.<p>The human body has excellent protection systems. The moisture in the air helps in trapping foreign particles in the nasal passage. In fact, research has shown that high relative humidity of 80% and above can significantly neutralise the Covid-19 virus. However, high humid conditions can be uncomfortable for most people if the ambient temperature is high.</p>.<p>Taking all this into consideration, the Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE) has recently issued guidelines that recommend setting the room temperature between 24°C and 30°C, while keeping the humidity level between 40% and 70%. It’s also recommended that natural or mechanical ventilation be provided to have good outside air inflow which helps in air changes which is critical in multi-occupant public spaces.</p>.<p>Air conditioning is categorised based on the types of indoor units installed: (these indoor units may be connected via refrigerant or chilled water pipes to the outdoor units. Thus, to limit risk of Covid-19 infection by air, ventilate indoor environments with outdoor air as much as possible. Mechanical ventilation systems and air conditioning systems are better as compared to opening the windows because they improve the quality of the outdoor air with constant filtration. </p>.<p><br /><em><span class="italic">(The author is executive secretary, ISHRAE)</span></em></p>