Indoor air quality refers to the air quality within our homes. This is important as it relates to our health and comfort as the building occupants. Indoor pollution sources can release gas and particles in the air and are the primary cause of indoor air quality problems in our houses. Inadequate ventilation can lead to an increase in indoor pollution by not removing stale polluted and replacing it with fresh air.
Unseen mould growth behind wall linings and external cladding can be a health risk to the occupants, particularly the young or elderly, or those with asthma. This and also lead to visual deterioration including staining of plasterboard linings as a result of moisture trapped behind the linings leading to ugly stains and swelling. Another little understood issue is the reduction in the building’s energy efficiency due to moisture in the insulation. This results in a loss of thermal performance. Moisture trapped within the structure commonly can also result in long term structural decay including corrosion of metal structures, timber rot, loosening of nails as timber swells, and cladding rot or swelling which can result in costly rectification work.
Outdoor air is not the only source of water vapour. A family of four can easily generate between 7 and 22 kg of water vapour per day. Temperatures above 20 degrees C and water vapour levels over 50% can lead to a rapid expansion of the dust mite population. Above 70% relative humidity moulds and fungus can develop on surfaces in a building. These organisms can produce toxins and irritants which can effect respiratory health
Good ventilation and vapour open construction are essential to good indoor air quality. Buildings need a suitable ventilation strategy preferably a controlled ventilation system with energy recovery (mvhr) supplying consistent fresh filtered air. A key part of this strategy is to ensure that the building is air-tight and that thermal bridges have been eliminated or at least minimized and checked to ensure that they do not create a health risk. The building envelope needs to be wrapped in an envelope system that is waterproof and vapour open so that any interstitial condensation (in the insulation layer) does not stay trapped in the wall and can work its way to the outside air.
Every inch of our homes are not only beautifully designed, they are calculated and built to surpass the World’s most rigorous energy efficiency, comfort and sustainability standards for buildings. Every component, every wall, window and even appliance is taken into consideration when meeting the Passivhaus performance standards
To date there have been over 60,000 Passivhaus units built around the world.
available from 10:00 – 19:00
Heidelberg Village Passivhaus Community, Heidelberg, Germany