Paper 6: Volume 4 No.1 June 2005 Edition
Sound Measurements and Natural
Ventilation in Schools
Alice Andersen1 and Carl Hopkins2
1WindowMaster A/S, Skelstedet 13, 2950
Vedbaek, Denmark
2BRE Acoustics, Bucknalls Lane, Garston, Watford WD25 9XX, UK
Abstract
Natural ventilation using open windows is an energy
efficient and effective method of providing a good indoor air climate in
schools. However, open windows not only let fresh air into the building
but also external noise. The availability of automatically controlled
windows enables precise control over the window opening distance in
comparison with manually operable windows. This paper considers the
benefits of using small opening distances to provide sufficient
ventilation for a good indoor climate as well as attenuation of external
noise. Airborne sound insulation tests on a window with different opening
distances show that the sound insulation varies significantly depending
upon the opening distance; the smaller the opening distance, the higher
the sound insulation. In many cases, an opening distance as small as 1 to
2 cm can not only provide sufficient ventilation for a good indoor
climate, but also adequate sound insulation. The results of sound
attenuation tests, performed at BRE in the United Kingdom, are presented
in this paper. In addition, empirical results from 3 different naturally
ventilated schools, including two in Denmark and one in the UK are
described. These results indicate that often only small opening distances
are required to obtain a comfortable thermal and atmospheric indoor
climate based on measurements during the year.
Key words: natural ventilation, demand control,
automatic control, sound attenuation tests, schools, control and indoor
climate, pulse (purging) ventilation.
Key words: airtightness, natural ventilation, stack
ventilation, CO2 concentration, apartment buildings.
References
BS EN 20140 10:1992:
(1992) “Acoustics Measurement of sound insulation in buildings and of
building elements. Part 10. Laboratory measurement of airborne sound
insulation of small building elements”.
BS EN ISO 717-1:1997:
(1997) “Acoustics Rating of sound insulation in buildings and of
building elements. Part 1. Airborne sound insulation”.
BB93: Building Bulletin
93: (2003) “The Acoustic Design of Schools”, produced by DfEE. (ISBN:
0 11 271105 7).
DS474: (1995) “Code for Thermal Indoor Climate”,
Denmark
.
Heiselberg P, Svidt K and
Nielsen PV: (2001) “Characteristics of airflow from open windows”, Building
and Environment, 36, pp859-869.
Heiselberg P, Bjørn E and
Neilsen PV: (2002) “Impact of open windows on room airflow and thermal
comfort”, International Journal of Ventilation, 1, (2),
pp91-100.
The Education (School Premises) Regulations 1999: (1999) ISBN 0 11
080331 0.
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