Indoor AIr Quality

How clean is the air we breathe indoors?

Indoor air can be five times more polluted than outside air. For a generation that spends most of our time indoors, not to mention our now locked down reality, a better understanding of indoor air quality (IAQ) and healthy lifestyle changes can make all the difference.

by Christoff Van Wyk

Why do we need fresh air in a building? Fresh air dilutes the CO2 levels, reduces the concentration of airborne diseases, acute syndromes and other indoor air pollution.

Insufficient cleaning, poor ventilation, pollutants from inside sources, pollutants from outside sources and contamination due to inadequate moisture control are the main causes of poor IAQ.

Poor indoor air can result in a whole range of illnesses including allergies and asthma. People are 40% more likely to have asthma when living in a damp and mouldy home. It is often difficult to detect the cause of many of these illnesses as they usually make a gradual appearance. Children and the elderly are especially susceptible.

What can be done?

We can start by becoming aware of the problem, re-thinking our lifestyles and building differently.

1. Open up the windows more often

In South Africa our SANS (South African National Standards) regulation gives us a minimum total external openable windows or doors sizes to be 5% of the floor area of the room. For adequate natural ventilation to take place, it is recommended to open more than one window 3 to 4 times a day for at least 10 minutes at a time.

2. Mechanical ventilation

A well-ventilated office can double cognitive ability, according to the Building the Business Case: Health, Wellbeing and Productivity in Green Offices report, released by the World Green Building Council in October 2016.  Opening some windows is a very effective way of ventilation but the disadvantage is that it is not constant as the windows are not always open. Or if the wind is blowing too strong or cold and the windows are kept close, it results in no ventilation. For the same reason natural ventilation is not allowed for areas with air conditioning and forced mechanical ventilation is needed in such rooms. Air conditioning is just circulating the same air in the room and cool or heat it, it is not diluting the CO2 or airborne disease levels.

Forced mechanical ventilation is fresh air with a fan and ducting. The SANS regulations also prescribes the l/s or airchange rate to use for different applications. Case studies from office spaces and school classrooms also confirm that proper mechanical ventilation can drastically reduce the amount of sick days taken.

There are various affordable air quality monitoring devices available on the market. Existing buildings with poor IAQ can easily be upgraded with mechanical ventilation systems, while new buildings should be designed with these system from the get start.

3. Green principle

In South Africa, Green buildings are required to provide 1.5 times the amount of fresh air prescribed by SANS. Although this increases the heat load and power consumption of the building, the increase in IAQ creates a much healthier work environment. This increase in heat load and power consumption can be reduced by the use of enthalpy wheels or similar solid plate heat exchange systems.

Several case studies across the globe has proven that the increased fresh air rates in green buildings lead to much lower sick leave taken by employees than those in occupying traditionally built buildings.

4. Purify with plants

Indoor plants are not merely decorative, but according to NASA’s Clean Air Study there are numerous plants that are effective in detoxifying the indoor air we breathe.

The Building the Business Case: Health, Wellbeing and Productivity in Green Offices report, released by the World Green Building Council in October 2016, reveals stōk’s headquarters in San Francisco managed to decrease hours of problematic CO2 levels by 39% by installing a portable green wall in a their main conference room.

Stōk installed an air quality sensor to examine CO2, VOC (volatile organic compounds), and Particulate Matter (PM) concentrations and see if pollutant levels were above recommended ranges. Before installing the green wall, 15% of work hours had problematic CO2 concentrations above 1,000 ppm (parts per million).

5. Let the light in

Natural light is another vital contributor to our indoor health. Exposure to sunlight increases the brain’s production of serotonin (a hormone associated with an elevated mood).  Lack of direct sunlight causes health issues such as vitamin D deficiency, which can contribute to feelings of tiredness, fatigue and low mood. Several case studies have proven that patients in hospital rooms with more natural light, make a quicker recovery than those in rooms with low levels of natural scenery and light.

Letting some natural light in, lowers the need for artificial light and electrical appliances that emit harmful chemicals. All while creating plant-friendly spaces that also increase the IAQ.

6. Limit the use of carpets & upholstery items

Carpets and upholstered furniture are known for trapping particles and pollutants. Vacuuming frequently with an effective device can help keep carpets clean, but not even hot-water extraction can get rid of all contaminants.

Carpets are also an ideal environment for dust mites that leave highly allergenic excrement. When carpets get wet, it becomes a breeding ground for mould and mildew. In fact, most experts recommend that any carpet that has been wet for over 24 hours be removed, because there is no effective way to eliminate the mildew growth.

7. Limit the use of chemicals, electronic devices & plastics

Since many conventional cleaning products are high in harmful chemicals, it is important to choose safer low-VOC (volatile organic compounds) products or try out some natural recipes and make your own.

It is a good idea to make a habit of switching off electrical appliances like the TV, computers and copy machines when not in use as they also emit chemicals that contribute to a poor indoor climate.

Warmed up plastics is another source of chemicals indoors. Plastic items like toys on a heated floor or placed in direct sunlight can give off toxic fumes.

Paying attention to the IAQ in our buildings and ensuring there is proper ventilation can tremendously contribute to increased productivity, improved employee satisfaction, lower sick leave days and reduced health costs. There are many ways to create healthier indoor air. Some are quick and easy, others take more time but will be well worth the effort.

NWE Consulting Engineers

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