Air Quality in Passive Houses

Poor housing gives rise to unhealthy living standards.

The sad thing is that houses built today are the unhealthy houses of tomorrow.

The illness people suffer fall into two categories.

a Sick Building Syndrome in which people are affected by being in the building and recover after they leave.

b Building Related Illness in which illnesses can be diagnosed by reason of living in the building. Such illnesses are normally attributable to building contaminants.

• Home owners have discomforts such as headaches, eye and nose infections.

• They may suffer from dry coughs have itchy skin and in extreme cases nausea and dizziness.

• They will be suffer from fatigue and poor concentration.

• The symptoms are not normally apparent and most people find relief after they leave the building.

Indicators of BRI include:

• Aches pains coughs etc.

• The reason for the complaints are definable.

• The recovery periods are longer.

• Complainants may require prolonged recovery times after leaving the building.

Problems experienced by occupants are compounded by the fact that they feel trapped in an unhealthy environment.

This leads to other problems such are depression etc.

The following have been cited causes of or contributing factors to sick building syndrome:

Inadequate ventilation: Inadequate ventilation is a major contributor to SBS.

Poorly ventilated houses give rise to an increase in air pollutants.

In addition poor ventilation will cause a rise in moisture levels which are a prime contributor of dampness to cold surfaces such as walls and windows.

Poor ventilation reduces the houses ability to remove offensive body odours etc. Chemical contaminants from indoor sources:

Air pollution is normally associated with indoor sources.

Carpets upholstery wood products cleaning agents etc emit pollutants into the air.

Volatile Organic Compounds (VOC) such as formaldehyde, smoking contribute large amounts of VOC’s.

In sufficient concentrations it is responsible for acute health problems.

Combustion associated from fires gas and oil burners produces carbon monoxide, nitrogen dioxide as well as respirable particles.

In an unvented or poorly vented house the above are responsible for many of the problems outlined above.

Biological contaminants: Houses can be affected by dampness pollen bacteria and mould.

In a house with poor ventilation these are compounded by stagnant air and lead to various symptoms such as asthma coughs allergic reactions etc.

Finally Radon gas build up is a real risk in poorly ventilated houses and is a major cause of cancer.

Passive Houses deal with air quality in a specific way.

The heart of any Passive house is the heat recovery system.

The system removes air from the house in a controlled manner.

The air is removed in all rooms which are prone to dampness odours etc and fresh air is supplied to living areas such as living areas bedrooms etc.

The extraction and delivery of fresh air is balanced.

By removing air from the house in this way the optimum use of fresh air is achieved.

By heating the incoming air by way of a heat exchanger with the expelled air the air temperature is maintained.

If the air requires further heating to maintain the ambient temperature the air intake can be heated.

This will occur only infrequently to maintain the heat balance.The incoming air is filtered and removes small particles such as pollens etc.

This leads to a much healthier internal environment.