A guidance document for operation of HVAC (heating, ventilation and air conditioning) systems in the residences, commercial buildings and hospitals was issued by Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE). The Guidance covers standalone and central air-conditioning systems. The Concerns related to temperature humidity, ventilation and filtration are clearly addressed in the ISHRAE COVID-19 guidance document.
ISHRAE President message on COVID-19
YouTube Link: youtu.be/ZIVZJkjlTqE
ISHRAE’s COVID-19 guidance document refers to studies conducted at various RH levels showing that using viral culture methods, low temperatures (7-8 Deg C) were optimal for airborne influenza survival with virus survival decreasing progressively at moderate temperature (20.5-24 Deg C) and further decreases at higher (greater than 30 Deg C) temperatures.
ISHRAE recommends safe operation of air conditioning & cooling systems with indoor air temperature and humidity set between 24 Deg C – 30 Deg C and 40%-70% respectively. Dry climates can set temperature closer to 30 Deg C and operate fans to improve air movement for comfort.
Commercial buildings have multiple occupants and transient visitors and thus the need for additional precautions, especially in the operation of their air conditioning systems. Hence, it would be prudent for all commercial buildings to limit risk by ventilating the indoor environment with outdoor air as much as possible. As per this document Mechanical ventilation and filtration provided by a Central Air conditioning system, can perform this function most effectively compared to simply opening the windows, because they correctly ventilate the space and improve the indoor air quality with prescribed outdoor air filtration.
In the healthcare sector, ISHRAE recommends converting general patient rooms and ICUs into COVID-19 patient areas with specific considerations pertaining to the HVAC systems in use. According to the guideline, the conversion of the rooms would first require changing the room into a non-recirculatory system. This can be achieved by blanking-off the return air vents in the COVID-19 patient rooms. It is important to make sure that the air handling unit has the provision to receive adequate outdoor air supply and the exhaust air from the room is treated as per the methodology recommended.
Mr. Richie Mittal, President ISHRAE said, “While the world continues to fight this global pandemic of COVID-19, we, at ISHRAE, have launched a guidance documents that shall reduce the impact of the virus in residences, offices and hospitals. The documents includes a section for operation and maintenance and safety guidelines for service technicians.”
The Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE), was founded in 1981 at New Delhi by a group of eminent HVAC&R professionals. ISHRAE today has more than 28,000 HVAC&R professionals and Student-members. ISHRAE operates from 43 Chapters and sub Chapters spread all over India, with HQ in Delhi. It is led by a team of elected officers, who are members of the Society, working on a voluntary basis, and collectively called the Board of Governors.
At this time of Lockdown, the Wheels of ISHRAE keep turning through online Meetings and Webinars. ISHRAE’s key Technical deliveries are Research, Standards, Education and Publications. Visit www.ishrae.in to be updated.