Limit the spread

Paul Lucas, MD at Artic Constructing Services discusses how HVAC techniques can promote infection manage inside a healthcare environment

With airborne transmitting accounting for more than a third of most hospital-obtained infections, it is very important explore ways of limiting the distribute of contagious infections and respiratory system infections. Airborne infections are usually transmitted from a person to some other through droplets of humidity released from top of the respiratory system through coughing and sneezing. Some virus droplets, like COVID-19, stay in the air for three hours and will end up being carried by the airflow because of their size. That is why, if taken care of and optimised properly, HVAC systems enjoy a pivotal function in preventing hospital-acquired bacterial infections.

Research have consistently proven that ventilation is among the key elements that influence airborne tranny, highlighting the significance of HVAC techniques in reducing the chance of healthcare sufferers and staff getting infectious viruses. As a total result, maintaining good quality of air is a critical technique in decreasing infection prices in healthcare conditions. But what actions could be taken to assist HVAC systems manage the spread of disease in healthcare conditions?


With the planet Health Organisation(we) reporting that bad ventilation increases the threat of transmitting COVID-19, the safest indoor space is one which is receiving oxygen which replaces the stale indoor air constantly. Changing stagnant air with oxygen from outside dilutes the contaminants that linger in the indoor air and decreases the chance of airborne transmission.

The air exchange rate represents the amount of times fresh outdoor air replaces indoor air within an hour. A study(ii) right into a hospital in Hong Kong suggested that throughout a pandemic, the new air exchange rate ought to be nine times within an hour. These findings highlight the significance of adjusting the HVAC system’s settings to circulate more oxygen round the hospital every hour.


Surroundings filtration plays an essential role in avoiding the distribute of infection, with research showing a confident correlation between top quality filters and decreased airborne transmission risks. Made to filtration system 99.97% of contaminants with a size of 0.3 microns, Higher Performance Particulate Air (HEPA) filters are generally found in healthcare environments and also have demonstrated great performance filtering COVID-19 droplets along with other airborne contaminants. Health care guidelines around air flow filtration claim that HEPA filters work in most patient treatment areas, lowering the chance of infection.

To sustain the performance of the HVAC program, air filters ought to be regularly changed or even cleaned to make sure that they don’t become clogged and much less effective. The kind of filter and its particular MERV ranking will indicate how usually it must be changed, however in a healthcare establishing, filters ought to be changed more often because of the higher risk of infections presented by the healthcare environment.

DEEP Thoroughly clean THE HVAC SYSTEM

With industry specialists arguing that unclean HVAC systems tend to be less efficient, cleansing the complete HVAC system will be another strategy applied to reduce the chance of airborne infection within hospitals. An intensive HVAC clean can boost indoor quality of air, lower the chance of airborne infection, expand the longevity of the machine, and offer energy savings.

To improve the performance of an HVAC program, the following must become cleaned:

  • Condensate drain
  • Evaporator coils
  • AC ducts
  • Air flow filters
  • The external of the device

When it involves infection control, cleansing the evaporator coils is essential because dirty coils will be the perfect location for mould particularly, bacteria, along with other contaminants to develop. The atmosphere moving through the coils offers been filtered already, meaning any bacterias in the coils could be dispersed throughout the medical center. Unclean AC ducts bring a similar risk and really should end up being routinely cleaned to mitigate the chance of infectious droplets getting carried by airflow through the machine and into medical center wards.


Within healthcare environments, planned preventative maintenance (PPM) is essential because it means that HVAC techniques are compliant with safe practices legislation while enhancing infection control. A stringent PPM plan reduces the regularity of unplanned fixes and guarantees the operational program is working at peak efficiency, reducing the transmission associated with airborne droplets thereby.

In accordance to the Section of Energy(iii), 25 to 40 % of surroundings flowing through HVAC techniques is lost because of leaky ductwork, producing checking the duct system very important. To further assistance the circulation of oxygen around the hospital, some type of manual intervention could be required to raise the oxygen exchange rate, fully open dampers, and recirculation paths to boost airflow close.

Additional PPM tasks that enhance the performance of an HVAC program include:

  • Recharge refrigerant and repair refrigerant leakages
  • Verify and lubricate belts, bearings, along with other moving parts
  • Check and calibrate system controls and thermostats
  • Inspect heat exchanger and operation of the fan