Breathing fresh, indoor & outdoor

Understanding and controlling common pollutants can help reduce your risk of health concerns

Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns. Here, industry experts share their opinions and suggestions on improving IAQ and minimising air pollutants, indoors and outdoors.

Indoor air quality in buildings
According to the ASHRAE Standard, IAQ is defined as “air in which are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80 per cent or more) of the people exposed do not express dissatisfaction”.

Kenneth Gong, BSc, MBA, MASHRAE, Technical Manager, TROX Malaysia Sdn Bhd, says, “Good IAQ is important to ensure healthy and comfortable indoor working or living environment for building occupants. If IAQ is poor, this could lead to Sick Building Syndrome (SBS), which can reduce productivity due to poor health or sickness affecting the building occupants.”

He further states that to maintain good IAQ in buildings, one has to evaluate the quality of outdoor air that is brought into the building via the Heating, Ventilation and Air-Conditioning (HVAC) system, which includes any form of mechanical ventilation systems.

“It is mandatory to supply sufficient outdoor air to the building for respiration purpose and to effectively remove contaminated air in the building to outdoor. Poorly designed and maintained HVAC system could lead to poor air distribution, dampness in the building which will encourage fungal and/or dust build-up in ventilation ductwork that will give rise to dust mites,” Gong suggests.

Other sources of air contaminants that are commonly generated in the building includes gaseous pollutants such as carbon dioxide, body odour and cigarette smoke generated by the building occupants and volatile organic compounds that are emitted from building furniture and materials such as carpet glue and paints for example, including any pollutants that are generated by office or production equipment within the buildings.

Maintenance of filters
Usually the most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions.
Some sources, like those that contain asbestos, can be sealed or enclosed; others, like gas stoves, can be adjusted to decrease the amount of emissions. In many cases, source control is also a more cost-efficient approach to protecting indoor air quality than increasing ventilation because increasing ventilation can increase energy costs.

Frank Taaning Grundholm, Vice President – Global HVACR Sales – Drives, ABB, says, “We do need ventilation, but we need to apply the relevant filtering, so that we can prevent the particles from entering the building.” He further adds that more automation is required to monitor the filters from getting clogged up. “So we need to make sure that filters get replaced on the building at the right time. That’s something we’re integrating into our drives where we can get information about the filter clogging and then alert the customers when it’s time to change.”

Ventilation improvements to improve air quality
The local by-laws including established engineering standards would determine the minimum outdoor air to be supplied, ranging between 5 to 20 litres per second per person. According to ASHRAE, “Many studies have found that occupants of office buildings with higher ventilation rates have fewer sick building syndromes.”

“Such recommendations, however, do vary from one country to another. Therefore, it is important to determine what the recommended local statutory ventilation requirement is for the relevant building,” says Gong. It is also important to take note that the positioning of the fresh intake for the HVAC system should not be compromised by any local source of pollutant.

For example, one should not position the fresh air intake next to a cooling tower. Failing that, if the outdoor air quality is generally poor, then special air filtration other than what is commonly used in a HVAC system should be employed to remove the outdoor air contaminants.

Gong also states that generally, most air handling units (AHUs) will have a primary and secondary air filtration system. “The course filter will act as the first stage air filtration, which is a disposable or washable type air filter for removing course airborne particles. Then follow with a fine filter with efficiencies ranging from 40-95 per cent as the second stage air filtration system depending on the building location and intended application. High Efficiency Air Particulate (HEPA) filters will only be needed as a third stage air filtration system where exceptionally high IAQ is required,” he adds.

However, Frank says that most people put up a schedule for maintenance of filters. “But, if the air is actually clean, there’s no clogging of the filter. And, if you still exchange the filter based on the schedule, you’re wasting resources. Of course, you’re still getting the energy saving because you have a clean filter, but you already replaced a clean filter. For this reason, we’re looking at how we could optimise energy consumption as well as material usage in the buildings,” he suggests.

More outdoor air to curb indoor air pollutants
According to United States Environmental Protection Agency, another approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming indoors.

Ventilation and shading can help control indoor temperatures. Ventilation also helps remove or dilute indoor airborne pollutants coming from indoor sources. This reduces the level of contaminants and improves IAQ. Carefully evaluate using ventilation to reduce indoor air pollutants where there may be outdoor sources of pollutants, such as smoke or refuse, nearby.

The introduction of outdoor air is one important factor in promoting good air quality. Air may enter a home in several different ways, including:
through natural ventilation, such as through windows and doors
through mechanical means, such as through outdoor air intakes associated with the heating, ventilation and air conditioning (HVAC) system through infiltration, a process by which outdoor air flows into the house through openings, joints and cracks in walls, floors and ceilings, and around windows and doors.

Natural ventilation describes air movement through open windows and doors. If used properly natural ventilation can at times help moderate the indoor air temperature, which may become too hot in homes without air-conditioning systems or when power outages or brownouts limit or make the use of air conditioning impossible.

Natural ventilation can also improve indoor air quality by reducing pollutants that are indoors. Examples of natural ventilation are opening windows and doors, and window shading such as closing the blinds.

Effectiveness of air cleaners
There several different air cleaners available in the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems. Some air cleaners are highly effective at particle removal, while others, including most table-top models, are much less so. However, they are generally not designed to remove gaseous pollutants.

According to United States Environmental Protection Agency, the effectiveness of an air cleaner depends on how well it collects pollutants from indoor air and how much air it draws through the cleaning or filtering element.

A very efficient collector with a low air-circulation rate will not be effective, nor will a cleaner with a high air-circulation rate but a less efficient collector. The long-term performance of any air cleaner depends on maintaining it according to the manufacturer’s directions.

Air conditioning efficiencies
Meanwhile, Kulwant Singh, Entrepreneur and Founder, Kleanwave Solutions, says that the alarming effects of global warming have resulted in urgent call for action and innovation in HVAC industry. “The solution will be an efficient and climate-friendly cooling technology with less impact on climate, and it is within our reach. The giants of HVAC&R industry can make it possible.”

Singh feels that consumers care more about price, brand and looks more than anything else. “Although regulatory authorities are trying their best, they are not able to apply much pressure with regard to efficiency standards.” He suggests that companies should spend more on research and development, and should come up with high-efficiency units with cheapest cost rather than spending on advertising and aesthetics.

Good IAQ is important to ensure healthy and comfortable indoor working or living environment for building occupants
Kenneth Gong, BSc, MBA, MASHRAE, Technical Manager, TROX Malaysia Sdn Bhd

We do need ventilation, but we need to apply the relevant filtering, so that we can prevent the particles from entering the building
Frank Taaning Grundholm, Vice President – Global HVACR Sales – Drives, ABB

Companies should spend more on research and development, and should come up with high- efficiency units with cheapest cost rather than spending on advertising and aesthetics
Kulwant Singh, Entrepreneur and Founder, Kleanwave Solutions