INDOOR AIR QUALITY IAQ

See also Ventilation >

A building's Indoor Air Quality (IAQ) is a combination of many factors. Materials used in building construction, types of insulation, amount of ventilation and building design are all major contributors to a building's IAQ.

Ionisers (or ionizers) can be used to clean air in interior spaces. These are a very low cost solution as filtered air conditioning can be very expensive. Ionisers (or ionizers) work by sending out streams of negatively charged ions, which cause floating particles to become charged and then stick to surfaces.

They can accumulate dirt behind their mounting which looks nasty. They are advertised as being good to remove pathogens such as SARS or H1N1 flu viruses, but this is of little effect as the ionisers (or ionizers) work with a slow volume method, rather than intercepting sprays of viruses or bacteria from a sneeze.

Mould and allergens affect the IAQ of a building. These are often bought into a building in two main ways. The first is through the moisture built up in a building because of insufficient ventilation systems. The second is by people and animals, clinging to clothing etc.

Moisture can get into a building by various means, including soaking in through the ground, poor roof design/broken tiles, and from human activity (showering, tumble dryers etc.). If this moisture is not removed quickly it encourages mould growth. The spores mould produces have a negative effect on human health, particularly in people with asthma and other respiratory disease.

Carbon Monoxide is perhaps the most dangerous of all indoor pollutants. It is a colourless odourless gas, which is often a by-product of incomplete burning of fossil fuels. Common sources around the home include central heating boilers and tobacco smoke. Anything that can produce fossil fuel should be adequately ventilated (check chimneys, flues, vents etc. for blockages) to ensure Carbon Monoxide does not build up within a property. Symptoms of Carbon Monoxide poisoning include drowsiness, nausea, headaches, and dizziness. When exposed to in high quantities it can be fatal.

See also:

• Air conditioning tips >
• Types of air conditioners >
• Maintenance of air conditioners >

Radon is an invisible radioactive gas that can seep into a property from the ground. Radon is prevalent in North America and Europe. Radon is a heavy gas so accumulates at floor level. Properties with basements can be particularly susceptible.

There is a grading for the amount in different areas, which will appear on a UK Local Government search. Some rocks such as limestone provide higher levels of radon emission.

Radon has been linked to various illnesses including lung cancer. Testing for radon can be done at home using readily available kits and more stringent tests should be done on planned construction sites if a new build is being considered.

'Sick Building Syndrome' (SBS) is a condition that affects people in buildings which suffer from bad IAQ. It is a mix of conditions, including headaches, nausea, sensitivity to odours and tiredness.

Using green building techniques has been found to reduce the likeliness of SBS. For example natural wool insulation traps chemicals such as formaldehyde and sulphur dioxide. Paint with a low VOC (Volatile Organic Compound) quantity release less harmful solvents into the atmosphere.

Ventilation systems should be design to work efficiently to cut down on the amount of pollutants in an indoor atmosphere. Systems should be used which can completely change the air in the building a couple of times an hour.

This prevents air going stale and moist. Filters can be placed on to the intakes of ventilation systems to block out particles that can affect IAQ such as pollen and dust, which acts as food to mould and microscopic life forms.

Passive Air Conditioning

Passive or semi-passive cooling methods such as cross-ventilation (gaps at angles to allow wind flows) and wall, floor or ceiling mounted fans can provide a large amount of cooling.

Air Conditioning

Many people suffer from IC (air conditioning) fatigue such as headaches, sore eyes, itchy skin and other allergy-type reactions.

ICU (air conditioning units) have to be regularly maintained, and often they are not, especially in budget locations such as cheap flats or hotels.

It is more green to cool than heat due to lower energy costs so everyone should move to the tropics.

See also Ventilation >