Camfil sustainability and efficiency specialist, Philipp Schluter, explains why maintaining good Indoor Air Quality (IAQ) is crucial for overall health and well-being.
Good IAQ is associated with better overall physical health, improved mental health and better productivity and problem-solving abilities.
Conversely, when a building has poor IAQ, it can have a detrimental effect on occupants. Indoor pollutants such as particulate matter and volatile organic compounds are responsible for a variety of health issues, including respiratory problems, and can exacerbate existing conditions.
In fact, in 1983, the World Health Organisation (WHO) coined the term ‘sick building syndrome’ (SBS) to refer to situations where building occupants exhibit a number of symptoms that appear to be linked to time spent in that building, but where no specific illness or cause is identified.
Indoor air pollution has also been linked to a number of serious, non-communicable diseases such as lung cancer, stroke, ischaemic heart disease and chronic obstructive pulmonary disease (COPD).
One 2017 study found that women living in highly polluted environments were almost twice as likely to develop dementia.
Identifying IAQ Issues
Dust buildup, visible mould or mildew, hot and cold spots and unpleasant odours are some of the common signs of poor IAQ.
Building occupants may also exhibit symptoms such as irritated eyes, nasal congestion, fatigue or even forgetfulness.
Delving into the root causes, some of the most common indoor air pollutants include:
Particulate Matter
Includes dust, smoke and tobacco smoke, pollen, dander, particles generated from combustion appliances such as cooking stoves, and particles associated with tiny organisms such as dust mites, mould and bacteria.
Gaseous pollutants
From building materials, furnishings, adhesives, paint and varnish, cleaning products and pesticides and combustion processes such as solid fuel heating sources with insufficient venting, gas cooking stoves, garaged vehicle exhaust, and tobacco smoke.
Environmental pollution
Outside contaminants such as vehicle fumes and industrial pollution can seep into buildings, but there is also a risk from naturally occurring gases such as radon. Bush fires and pollen storms can add severe environmental pollution and cost many lives every year.
Disease
Insufficient ventilation of enclosed spaces is the primary contamination vector of respiratory infections including COVID 19. These viruses can remain airborne as aerosols and spread through the air we breathe even without direct contact.
There are a number of other sources that can contribute to substandard IAQ, from asbestos-containing building materials to VOCs emanating from office equipment. This further underscores the importance of identifying and addressing IAQ issues.
Ventilation strategies
Natural ventilation is one of the most cost effective, sustainable ways to achieve better IAQ, taking advantage of natural airflow and windows to create opportunities for fresh air to circulate. However, it also brings the risk of allowing outdoor pollutants to migrate indoors.
Common outdoor pollutants that enter buildings include those emitted from vehicles, emissions from industrial facilities and outdoor allergens like pollen.
This is where mechanical ventilation comes into play. Well implemented mechanical ventilation includes filtration of ultrafine particulates, effectively removing indoor and outdoor pollutants, allergens, contaminants and extracting stale air for healthier IAQ.
Mechanical ventilation is an active ventilation system that uses fans, ducts and vents to ensure continuous healthy air supply to the occupants of buildings.
Reducing indoor contaminants where mechanical ventilation is unavailable or inadequate. Air cleaners or air purifiers are often used where mechanical ventilation is lacking to help improve the indoor air quality within the building.
Air cleaners work to reduce particulate levels, eliminate nuisance odours and remove airborne particles such as viruses.
However, air cleaners do not introduce ‘fresh’ outside air, and are more costly to operate than well designed mechanical ventilation.
Things to look for in an air cleaner:
- Make sure the air cleaner uses filters that qualify as a HEPA filter according to the Australian Standard AS4260:1997
- For the removal of odours or noxious gases (such as formaldehyde) the use of a combination molecular filter is necessary.
- Adequate sizing to your room requirements is advised. A small air cleaner in a big room will not have the desired effect. Know your airflow rate.
- Low noise levels are key. In many environments noisy air cleaners are a distraction. Choose air cleaners that maintain the required airflow rate with a low noise level.
Monitoring and testing IAQ
Keeping an eye on IAQ is easy through the use of monitoring devices and sensors. Through real-time insights into humidity, temperature, carbon dioxide levels and the presence of particulate matter and VOC pollutants, building owners and occupants can identify and address potential issues promptly.
Conducting periodic testing for pollutant levels also helps identify specific pollutants and their concentrations, enabling the implementation of targeted strategies that ensure a consistently high standard of IAQ.
Compliance with IAQ standards and regulations
While there are no specific legislated standards for IAQ in Australia, there are various guidelines and standards related to maintaining HVAC hygiene and ensuring IAQ.
These standards cover various aspects, including mechanical ventilation (AS 1668.2:2024), microbial control in air-handling and water systems (AS/NZS 3666:2011), air filters for general ventilation and air conditioning (AS1324 and AS/ISO16890) and ductwork for air-handling systems (AS4254).
Specific requirements and standards may vary depending on the type of building (residential, commercial, industrial) and its use.
Local and state regulations may also play a role, so it is important to check with relevant authorities and consult the most recent documents for up-to[1]date information.
When assessing the efficiency of air filters used in general ventilation equipment, AS/ISO16890 provides a uniform method for testing and classifying air filters based on their particle removal efficiency.
Improving indoor air quality is the single most important step to creating healthy buildings. Ensuring IAQ requires a multifaceted approach, starting with identifying the sources of indoor pollution.
From there, building owners and operators can implement effective ventilation strategies. This might involve selecting and maintaining appropriate filters and monitoring IAQ parameters.
By embracing the pursuit of IAQ, individuals and organisations can create healthier indoor environments, enhancing the well-being and productivity of occupants.