‘More than half of the air you’ll breathe in your lifetime is inhaled inside your home’
An article from World Green Building Council states that ‘An estimated 5.5 million lives were lost in 2013 to diseases associated with outdoor and household air pollution. These deaths cost the global economy about US$225 billion in lost workforce productivity and over US$5 trillion in welfare losses. China has lost substantial chunks of national GDP due to lower productivity from pollution – 6.5% in 2016. The annual cost of asthma and pulmonary disease is 82 billion Euros across Europe and CAN$8 billion in Canada, which we know is being worsened by air pollution’.
The major indoor air pollutants that affects the health of the occupants are pollutants released from cooking and heating with traditional biomass coal stoves, as well as toxic chemicals, such as Volatile Organic Compounds (VOCs), emitted from cleaning products, furnishings, and paints in your home.
Know the Basics: ‘Air Quality and Ventilation’
Indoor air quality is governed, to a large extent, by the materials and finishes that go into a building, as well as the activities of its occupants (cooking etc). The idea to minimise or eliminate the presence of toxins in the internal atmosphere through a combination of good ventilation and well-informed product selection.
A report by the Royal College of Physicians and the Royal College of Paediatrics and Child Health suggests that those susceptible to indoor air pollutants are at risk of major health conditions, such as cancer, heart disease and respiratory related illnesses.
With modern construction, some of the key culprits are the goods containing VOCs (volatile organic compounds) such as formaldehyde, which can off-gas low levels of toxins over the long term. VOCs are present in many conventional paints and adhesives, in addition to a range of common building materials such as treated timber, OSB (oriented strand board), MDF (medium density fiberboard) and plasterboard. Other common air quality issues include condensation and mold. This can be arrested by ensuring the building envelope is airtight.
The air quality issues can be mitigated by selecting robust yet chemical-free structural materials and finishes, as far as is practicable, and to ensure that adequate ventilation is provided in the design and best indoor air quality management practices are followed during the construction.
Adequate ventilation shall be provided by following the local regulatory requirements and the international standards. But it should be noted that if effective ventilation is not in place to remove harmful contaminants, it may create adverse effects on the overall Air Quality of the living space.
It is recommended to design a proper mechanical ventilation system to deal with the outdoor / fresh air supply. Nowadays, most of the international design standards recommends a high-quality filter in the ventilation systems to ensure a fresh, filtered and safe incoming air supplied into the space.
In addition to the ventilation and materials, it is important to build your home airtight because through the gaps in the envelope, the hot outdoor air can enter the building making mechanical systems inefficient and supports mold growth inside the living space.
It is to be noted that ‘Over five million people in the UK are thought to suffer from asthma, and this can be triggered by poor internal environment’. Mold growth is one of the major indoor environment pollutants, and it is one of the most complicated processes to remove or stop mold growth in a space once it is established or developed.
‘Envelope Airtightness’ is currently a major requirement that has to be addressed from design to construction of any building, mainly in the very hot and cold climates. Envelope airtightness can be ensured by conducting air leakage tests as per the ASTM or ISO standards. However, to ensure the integrity of the leakage tests; the tests shall be conducted by certified professionals from organisations like ATTMA, ABAA…etc. Also, to ensure the continuity of envelope insulation, thermographic tests can be carried out.
How a healthy home can be defined?
A healthy home can be defined as an airtight, highly insulated, energy efficient home that costs very little to operate and supports the occupant’s health and lifestyle.