Abstract:
Revisions of the UK Building Regulations are resulting in changes in the design,
construction, heating and ventilation of new and refurbished homes. There are
concerns that inadequate ventilation of these energy efficient homes could
result in increased levels of indoor pollutants. This study considers the possible
risk to occupant health due to exposure to combustion by-products, such as
carbon monoxide (CO).
Measurements of combustion pollutants during the 2010/11 heating season
were undertaken in 14 homes built/refurbished in accordance with 2006
Building Regulations or to a higher standard of energy efficiency, as well as 5
older homes over a two week period.
No WHO indoor air guidelines for CO were exceeded in any home. It was found
that there was a significant difference between CO and nitrogen dioxide in the
kitchen and the bedroom of the main study homes. Modelling of CO
demonstrated how situations of low ventilation combined with high and also
moderate source emission rates could potentially lead to air quality guidelines
being exceeded. Combustion, heating elements and some aerosols were found
to greatly increase the number of ultrafine particles (UFPs). Currently, no
guidelines for UFPs in air are available and there is limited literature reporting
their measurement.
The air quality measurements do not show that energy efficient homes pose
greater risks to health of occupants from combustion pollutants than other
homes. However, modelling suggests some scenarios could produce exposure
to CO exceeding health based guidelines. The study is considered as a
preliminary investigation, not representative of the wide range of different house
types and occupant behaviours that may influence pollutant levels and
exposure of occupants. It does provide valuable indicative data and identifies a
need for further work as current knowledge about indoor air quality in energy
efficient homes is limited and possible risks to health have not been fully
evaluated.
