An HVAC system is necessary to perform the functions of air filtration, cooling, heating, humidification, dehumidification, etc. These functions determine Indoor Air Quality (IAQ) in a building. IAQ can be defined as the nature or quality of air as it affects the health and well-being of building occupants. As per National Institute for Occupational Safety & Health (NIOSH) shows indoor pollutant level may be 10 to 100 higher than outdoors.

Poor indoor air quality can manifest respiratory diseases such as asthma and COPD. The burden of COPD in India has been estimated to about 15 million cases, causing about 5,00,000 deaths per year. Several large studies suggest that pollutants exert significant effects on the cardiovascular system. It has been shown that for any increase in mortality caused by pollutants, two-thirds of the effect was accounted for by cardiovascular diseases.

If the air inside a room is not cooled or heated as per the occupant’s satisfaction level, he or she may experience thermal discomfort. Further, proper dehumidification is also necessary for occupant’s heath otherwise it may accelerate microbial growth. Similarly, proper air pressure in patient isolation rooms is necessary to prohibit unwanted circulation of airborne pathogenic bacteria. Moreover, it is prudent to exhaust unnecessary chemicals properly from laboratories as these chemicals may travel in nonlaboratory spaces through air.

For these reasons, hospitals or healthcare facilities or clinics need to be more alert in ensuring proper IAQ in order to protect patients and staff from infections and occupational diseases.

The WHO data also shows that 9 out of 10 people breathe air containing high levels of pollutants. This has certainly created a huge amount of fear in the minds of people. The new data further reveals a stronger link between indoor and outdoor air pollution which can cause harm to many critical healthcare industries. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming, informs Ashwin Satish Bhadri, CEO, Equinox Labs.

Surendra Shah, Founder Chairman, Panasia Engineers, says, “Other than medical and physiological remedies, healthcare facilities are also required to take maximum care to provide a clean and pathogen free environment with controlled temperature, humidity and extremely efficient air filtration. Quantity and direction of air flow and the fresh air percentage are also controlled. There are strict standards that must be followed without exception. All this is not possible without a modern HVAC System specially designed for the purpose.

According to a survey, every 100 hospitalised patients, seven in developed and ten in developing countries acquire at least one healthcare-associated infection. Medical entities have to bear a huge cost due to the healthcare infections. It has been surveyed that Europe alone had to face 37,000 unnecessary deaths and extra days of hospital stays due to HAI. There’s a huge misconception that outdoor air is dangerous and indoor air isn’t. Whereas indoor air is much more harmful and can cause many uncertainties to human lives, Bhadri further adds.

Maintaining IAQ in Healthcare

The enrichment of air quality in hospitals, clinics, and other healthcare settings is an imperative factor of modern airborne hygiene procedures. Its value also extends to the occupational health and safety requirements in medical institutions. An enhanced air quality provides a healthier and pleasant atmosphere for patients, staff and visitors. This also leads in saving huge costs as it acts as a preventive infection control measure.

In healthcare facilities, the air quality levels in healthcare settings differ from department to department. Some areas require high-efficiency filtration of airborne microorganisms to protect patients, staff and visitors e.g. in operation suites, ICU and TB isolation rooms, whereas other areas require the filtration of gaseous contaminants, chemicals and odours to provide a safer and more pleasant working environment e.g., in laboratories, autopsy rooms, dental surgery rooms, pharmacies.

In laboratories, air quality is a vital factor in achieving production and research quality. Impure air can, at worst, lead to product recalls, expensive investigations and moreover a lower image and credibility. It is important that the authorities protect the staff from the particles by enforcing air filtration devices. The control of airborne microorganisms such as bacteria, viruses and fungal spores is of major importance in medical settings due to the fact that a number of diseases and infections can be transmitted by airborne pathogens. Due to the presence of such air pathogens, off lately HEPA filtrations have become quite popular in the medical facilities to dissolve these issues. Several areas within the medical and healthcare industries use HEPA filtration, some of which are obvious and some of which are less so, according to Bhadri from Equinox Labs.

Bhadri mentions that the neonatal department, the most sensitive department should be safe from any bacteria or virus that can harm the newborns. The use of HEPA filters on the incubators ensure that the air passing in and out is of a higher quality. HEPA filters are also used for daily cleaning purposes that helps to improve the air quality. With an antimicrobial coating, HEPA kills microbes and bacteria on contact ensuring these are off the sensitive surfaces. The HEPA filters are used for a number of things such as for cleaning equipment, industrial vacuum systems, medical laboratories in order to keep the air and surfaces clean.

Apart from patients, doctors and the entire staff can face the consequences of indoor air pollution health effects. The safety of healthcare staff can be ensured through efficient air filters that help to reduce particulate matter and allergens.

Shah from Panasia Engineers enlists the following new and stricter criteria for hospitals:

  • Lower temperature – Between 18- and 22 Degrees C.
  • Lower Humidity – Between 20 and 45 per cent
  • Better filtration – Down to 0.3 microns
  • Higher fresh air percentage – Up to per cent in some cases
  • Air distribution – Low velocity laminar unidirectional flow
  • Pressurisation – Positive, to prevent infiltration of untreated air from passages. However, it must be negative during fumigation to prevent pungent smell from leaking out.
  • All walls, floor and ceiling must be impervious to moisture.
  • Frequent and thorough cleaning including the filters and coils.

It is obvious that the HVAC equipment must be specially designed to meet these criteria. Given below is a drawing of a typical AHU for Operation Theaters.

The increasing awareness of poor IAQ has led the healthcare sector to be cautious and take preventive steps whilst mending the existing conditions. The sector thus cannot risk the health of thousands of patients and the faculty that are an integral part. Hospitals and other medical facilities thus will find its way to superior indoor air quality by working with the air impurities removal systems enrich a good living, concludes Bhadri of Equinox Labs.


Supriya A Oundhakar, Associate Editor