Indoor Air Quality and Its Significance

What Is Indoor Air Quality and How Does It Affect Us?

Having good indoor air quality (IAQ) must be a top priority in any building. Indoor air quality refers to the air quality within our homes and it is related to the comfort and health of building occupants. It is the depiction of pollutant concentrations and thermal conditions that may negatively affect the health, comfort, and performance of a building’s residents. To reduce your risk of indoor health concerns, you need to understand and eliminate common indoor pollutants. Indoor pollution sources release particles and harmful gasses in the air, resulting in poor indoor air quality.

Poor indoor air quality can have a detrimental effect on your short and long-term health. Headaches, irritation of the throat, nose and eyes, fatigue, and dizziness are some of the immediate effects of exposure to indoor pollutants. Lung disorders such as asthma, COPD, and lung cancer have been related to poor indoor air quality. It’s been seen in studies to contribute to an elevated risk of heart disease and stroke as well.

Sources of Indoor Air Pollution

Indoor air pollution can be generated by a variety of factors. Unfortunately, most conventional homes are built with materials containing toxic chemicals that pollute the indoor air quality and negatively impact your health. One such common toxic material is formaldehyde, which can be found in most pressed wood products that are used to make furniture, countertops, shelves, and cabinets. Other known sources of indoor air pollution include wood preservatives, oil-based paints, stains, carpet glue, and other adhesives. These materials emit harmful fumes that contain volatile organic compounds (VOCs). 

Construction and furnishing materials emit volatile organic compounds (VOCs) over weeks or years, which can lead to poor indoor air quality. The release of volatile organic compounds (VOCs) from consumer products, such as computers and printers, as well as cleaning products and air fresheners, is gaining popularity.

Outdoor air, fuel combustion, and human and animal respiration are the main sources of inorganic pollution gases in indoor air. Space heating (particularly open-flued gas and paraffin heaters), water heating, and cooking are the principal sources of combustion gases in buildings. Tobacco smoke and automobiles (in attached garages) are two other culprits. One of the biggest contributors to poor indoor air quality in a building is an attached garage. Carcinogenic contaminants and carbon monoxide present in car exhaust make its way into living spaces through doors and cracks in walls and ceilings adjacent to the garage. Prolonged exposure to the toxic garage air can negatively impact your health.

Heath issues related to indoor air pollution may show up years later, or soon after exposure. Some serious health conditions due to prolonged exposure to indoor air pollutants include respiratory diseases, cancer, and heart disease. These can be fatal or severely debilitating. Indoor air pollution has the potential to harm anyone. You’re more likely to be affected by poor indoor air quality if you have a lung ailment like COPD, asthma, or bronchiectasis. However, not everyone reacts the same way to the dust, debris, and gases in our houses. This is why it is imperative to have in place a solid indoor air quality management system to prevent the worsening of such pre-existing health conditions.

CO2 is a natural component of air, and it is only in rare conditions that it is present in significant proportions to pose a health risk. It can be found in buildings as a by-product of human and animal respiration, as a by-product of combustion, and as a component of soil gas. However, if it rises above the permissible levels, it can be severely detrimental to your overall health.

High Humidity and Damage It Does to Your Home and Health

If the relative humidity in your home routinely surpasses 60%, it can cause problems. Mould and mildew begin to form when the air contains water vapour over that level, and excess moisture can lead to structural decay, causing damage to your home and valuable items. Moisture in the insulation can reduce a building’s energy efficiency and lead to a loss of thermal performance.

Homes that lack proper ventilation trap indoor air pollutants and facilitate a favourable environment for mould growth. Prolonged exposure to mould can lead to asthma, allergic reactions and other respiratory diseases. These microscopic fungi can be found all over, but wet areas of the home provide ideal circumstances for them to settle on surfaces and thrive. Mould is black or dark green in appearance and can penetrate deeper into building materials, whereas mildew forms white or grey patches on surfaces such as shower curtains, windowsills, or tiles.

Air/vapour barriers are typically installed on the inside of your home’s walls to prevent warm moist air from accessing the surface, but they are never perfect. Moisture can collect in foundation materials, crawl spaces, and basements, causing structural issues. It causes materials to swell or contract when the moisture level in plaster, joists, or studs is constantly changing. As a result, high humidity can cause cracks, necessitating costly repairs.

Humidity Management

Removing moisture at the source, such as using an extractor fan in the bathroom, a range hood in the kitchen, venting a dryer to the outside, and only utilising externally vented gas heaters. Use passive ventilation, or a mechanical home ventilation system, if your home is tightly sealed. You need to seal air leaks, which allow humidity from outside to infiltrate. Installing a whole-house dehumidifier can remove water vapour from the air. Opening windows wide for just 10–15 minutes each day can lower moisture levels within a house while also increasing indoor temperatures through good insulation. According to the Building Research Association of New Zealand (BRANZ) study, buildings heated to 18°C experience significantly fewer periods of high humidity.

Solutions In Line With the Passivhaus Standards

For optimum indoor air quality, high ventilation and vapour open construction are required. Buildings require a proper ventilation strategy, preferably a controlled ventilation system with heat recovery (MVHR) that provides consistent fresh filtered air. We design our homes on the Passivhaus principles so that the building is airtight and that thermal bridges have been eliminated, or at the very least minimised, and tested to verify that they do not pose a health hazard. The building envelope is encased in a waterproof and vapour-permeable envelope system so that any interstitial condensation (in the insulation layer) does not remain trapped in the wall and can escape to the outside air.

Indoor Air Quality in a Passive House: Heat Recovery Ventilation Is the Key to Healthy Indoor Air

We design and build energy-efficient homes in compliance with Passivhaus (Passive House) standards. Passive houses are well-insulated with no thermal bridges, and have an airtight envelope, high performance windows/doors, and a mechanical ventilation heat recovery system (MVHR). Apart from being very energy efficient, passive houses offer improved and healthy indoor air quality due to continuous mechanical ventilation and filtered incoming air.

We eliminate the use of toxic materials when building passive houses and our biggest line of defence against indoor air pollutants is heat recovery ventilation. We use a mechanical ventilation heat recovery (MVHR) system to ensure the the continuous flow of fresh air throughout the home. The MVHR unit continuously brings in fresh air and exhausts old air while retaining 90% of indoor temperature. It recovers heat while providing fresh filtered air. With the help of the MVHR system, the stale air from the home is replaced with filtered, fresh and clean air every three hours. The heat recovery ventilation system filters out dust, smoke and pollen, allowing all air in the home to be clean.

Call us on 412 550 116 to know more about our services.