Paper 7: Volume 4 No.1 June 2005 Edition
The Reduction in Air Infiltration due
to Window Replacement in UK Dwellings: Results of a Field Study and
Telephone Survey
T Oreszczyn, D Mumovic, I Ridley and M Davies
Bartlett School of Graduate Studies, University College
London, UK
Abstract
This paper reports the findings of a field study and
telephone survey into the impact of window replacement on air infiltration
and moisture problems in UK dwellings. The results of a telephone survey
of 250 UK houses suggested that the installation of tight, well sealed
replacement windows does not appear to be causing a significant increase
in IAQ problems as perceived by the occupants. After having windows
replaced only 2% of respondents (5 households) reported worse problems
with condensation and only 1% (3 households) reported worse problems with
mould. However, the results of "before and after" fan
pressurisation tests on ten dwellings suggested that the installation of
modern replacement windows reduced the predicted heating season mean
background air change rate by an average 0.23 ac/h (standard deviation
0.08 ac/h). Analysis of the results suggests that installation of
replacement windows in UK dwellings significantly reduces background
infiltration rates, and that 65% of dwellings in the UK would have a
predicted heating season mean air change rate below 0.5 ac/h after the
installation of new windows. Houses with high moisture production, and low
ventilation rates are potentially at risk from increased moisture problems
after window replacement and may benefit from the installation of
additional controllable ventilation during window replacement. However,
the telephone survey which indicates that window replacement has not
caused worsening IAQ suggests that occupants are ventilating adequately
for their moisture production rates. If increased occupant venting occurs,
then this may have the detrimental effect of increasing the space heating
energy consumption.
Key words: window replacement, air infiltration,
dwellings, indoor air quality, measurement.
References
British Standard BS 5368 Part 1: “Test Method,
Air permeability”. BSI
UK
.
BS EN 13829: “Thermal performance of buildings – Determination of air
permeability of buildings – Fan pressurization method”.
BSI
,
UK
.
CEN/TC 156: (2002) “Ventilation
for buildings – Performance testing of components/products for
residential ventilation – Part 1: externally and internally mounted air
transfer devices”, prEN 13141-1(e) CEN.
Davies
M, Ucci M, McCarthy M, Oreszczyn T, Ridley I, Mumovic M, Singh J and
Pretlove S: (2004) “A Review of Evidence Linking Ventilation Rates in
Dwellings and Respiratory Health – A Focus on House Dust Mites and
Mould”. International Journal of Ventilation, 3, (2),
pp155-168.
Hong SH, Ridley
I and Oreszczyn T: (2004) The Warm
Front Study Group. “The Impact on Energy Efficient Refurbishment on
Air tightness in English Dwellings”. Proc. Air
Infiltration & Ventilation Centre (AIVC) Conference, September 15-17,
Prague
.
Lowe R., Oreszczyn T and Robinson P: (1999) “Review of Existing Window
Energy Rating Systems and Outline of Possible Systems for the
UK
”. International Conference on the Use of Glass,
Bath
, pp209-220.
ODPM: (2001), “Approved
Document L1 - Conservation of fuel and power in dwellings: 2002
Edition”. The Stationary
Office
,
UK
.
ODPM: (2004) “The
Building Act 1984, The Building Regulations 2000, Review
of Approved Document F- Ventilation: A consultation package”,
ODPM,
London
,
England
.
Oreszczyn T and Pretlove
S: (1999) “Condensation Targeter II: Modelling surface relative humidity
to predict mould growth in dwellings”, Building Serv Res Technol,
20, (3), pp143-153.
Ridley I, Fox J, Oreszczyn
T and Hong SH: (2003) “The
Impact of Replacement Windows on Air Infiltration and Indoor Air Quality
in Dwellings”, International
Journal of Ventilation 1, (3), pp209-218.
Sherman
M: (1998) “The use of Blower Door Data”, Lawrence Berkley Lab Report
35173. LLBL
USA
.
Stephen, RK: (1998)
“Airtightness in
UK
dwellings: BRE’s test results and their significance”, Building
Research Establishment, BRE 359.
UK
.
|
