|
Ventilation is necessary to maintain a healthy and comfortable internal
environment and to rapidly remove pollutants such as moisture, volatile
organic compounds (VOC’s), allergens such as dust, oxides of nitrogen,
carbon monoxide, carbon dioxide, tobacco smoke and unpleasant odours.
Moisture is generally assumed to be the most significant of these
pollutants because of the high rates of generation from cooking, bathing,
washing, drying etc and the consequential condensation and mould growth
problems. It follows that if the ventilation strategy is based on
controlling this principle pollutant by heat recovery input / extract
ventilation then logically the other indoor pollutants will also be
adequately controlled.
Stale air, and air which is hot or humid, should be replaced at a
reasonable rate.
Good ventilation means providing a balance between energy efficient and
healthy indoor air best summed up by the catchphrase ‘Build tight –
ventilate right’.
The fresh air supply rate should not normally fall below 5 to 8 l/s per
occupant. This is best achieved by creating continuous air changes of 0.5
to 1.0 every hour, throughout the entire dwelling as specified in D.E.T.R.
Good Practice Note 268.
Although Building Regulations relate to new buildings, the guidance on
ventilation is applicable to existing dwellings and, most important of
all, the regulations are concerned with minimising the risk to health from
the build up of pollutants. KHRV150 helps to satisfy all of these
criteria.
|
