Literature review: Domestic Ventilation Practices
Lisa Gobio-Lamin, PhD Candidate
10th May 2012
Introduction
•
More energy is used in housing than in any other
sector in the UK.
•
Space heating is responsible for around 65% of the
UK’s total household energy use.
•
Domestic energy consumption rose by 31% from
1970 to 2009 with the largest increase occurring in
heating energy use (DECC, 2011).
•
Increase in energy for space heating can be attributed to the size of dwellings and rooms being
heated, occupants’ comfort preferences, window-opening behaviour and the external
temperature.
•
Householders’ increased standards of comfort have been blamed for home energy use not
declining despite improved dwelling energy efficiency.
•
Study found no statistical evidence for any change in reported thermostat setting between 1984
and 2007 (Shipworth, 2011).
•
If householders are not demanding higher indoor temperatures now than they did twenty years
ago, then what other factors could be influencing domestic heating energy use?
•
A building’s heating energy use is significantly influenced by occupant’s behaviour such as the
opening of windows & doors when the heating is on (Garland, et al. 1993; Anderson, 2009).
•
Window opening behaviour was found to have the largest effect on air change rates which can
significantly influence a building’s energy consumption (Wallace, et al., 2002).
•
This highlights the importance of investigating occupants’ window opening behaviour in winter.
Domestic Ventilation Practices

Direct observation of window opening behaviour was conducted for 120 dwellings in Cambridgeshire in winter
of 2006-07 by Fox, 2008.

Dwellings consisted of detached, semi-detached, terraced houses and flats.

The highest percentage of open windows were in the morning during the breakfast period than at other times
of the day. Result is consistent with the IEA Annex VIII study conducted in the Netherlands (Dubrul, 1988).

A higher proportion of open windows at the weekend than during the week by Fox, 2008 and also in a study in
Netherlands by Jacobs et al., 2010.

In flats and houses, a higher percentage of windows were open during the breakfast period than at other
times (Fox, 2008).

However in flats, bathroom windows were opened most frequently than any other windows during the
breakfast period.

In houses, bedroom and bathroom windows were opened the most during breakfast time. This is consistent
with a study by Brundrett, 1977.

Number of open windows decreased during the rest of the day in houses, with a slight increase occurring after
late afternoon into the evening which decreased overnight (Fox, 2008).

A higher proportion of occupants reported opening their windows in the morning and at night than any other
period of the day (Wouters & De Baets, 1986).
Factors that influence domestic ventilation practices
There are a number of factors that affect ventilation behaviour in dwellings. They include:
 Outdoor Climate
 Indoor climate preference
 Dwelling Type
 Window Design
 Perceived indoor air quality
 Household composition
 Occupancy & Time of Day
 Household Activities
Outdoor climate

Direct linear correlation between window use and external temperature when the outdoor temperature range
was between -10C to +25C was found (Dubrul, 1988).

Direct correlation with the number of opened windows and external air temperature (Fox, 2008 & Jacobs et al.,
2010).

A negative linear correlation between wind velocity and window opening was observed in the German study,
Annex VIII project (Dubrul, 1988).

A slight correlation between wind speed and number of open windows was found by Fox, 2008.
Indoor climate preference
•
Indoor climate preferences had a strong correlation with the way windows were used.
•
The studies from the IEA Annex VIII project showed that the higher the occupants’
preferred thermostat setting, the less windows were opened (Dubrul, 1988).
•
The preferred temperature in the bedrooms was lower than in the living rooms. Bedroom
windows were opened for much longer periods than the windows of other rooms.
•
Some of the windows in the main bedroom were kept open during the night even in cold
winter conditions (Dubrul, 1988).
Dwelling Type
•
Dwelling type influenced the length of time windows were open as well as the width/size of
the opened windows (Wouters & De Baets, 1986).
•
In houses, bedroom windows were open for longer than in flats. Living room and kitchen
windows were found to be open for shorter periods in houses than in flats (Wouters & De
Baets, 1986; Van Dongen, 1986).
•
In flats, the bathroom had the highest proportion of open windows whilst the kitchen had the
lowest number of open windows. The lowest proportion of open windows in houses and flats
were in the kitchen (Fox, 2008).
•
In flats, a higher proportion of windows were reported to be slightly open than wide open,
which was the opposite in houses (Wouters & De Baets, 1986).
Window Design
•
The design of a window, with regard to how it is hung in its frame and the direction of travel of the opening
part, influenced window opening (Dubrul, 1988).
•
Belgian research showed that bottom hung windows which open inwards were opened more frequently than
other types.
•
The German team found that during the winter months there was very little difference in the duration of
opened sash windows in the side-hung or bottom-hung position.
•
During the rest of the year, sash windows were opened in the side-hung position for a longer period than in
the bottom-hung position (Erhorn, 1986).
•
Bedroom windows were opened in the side-hung position for a longer duration of time than in
the bottom-hung position (Dubrul, 1988).
•
Living room windows were opened in the bottom-hung position for a longer duration of time.
This supports the findings that bedrooms are ventilated more than living rooms in winter.
•
Ventilation grilles were opened three times longer than casement/pivot windows in Dutch
dwellings. The duration of open fanlight windows were also twice that of casement/pivot
windows in the whole dwelling (Van Dongen & Phaff, 1989).
•
Reasons for these differences in use could be that different designs offer different areas of
opening and that some window designs are easier to open.
Perceived indoor air quality
•
A high proportion (63%) of occupants reported ‘dry indoor air’ and ‘the air smelling bad’ as the
reasons for opening their windows in winter (Andersen, 2009).
•
Some of the most frequent responses provided by occupants for opening their windows in
winter were to freshen up their dwelling, remove bad smells, avoid stuffiness and to get rid of
smoke (Brundrett, 1977; Wouters & De Baets, 1986).
•
The living room was ventilated for twice as long in dwellings where occupants smoked than in
non-smoking households (Van Dongen, 1986).
•
The need for fresh air in winter, especially in bedrooms was connected with health related
beliefs.
Occupancy & Time of Day
•
Highest proportion of open windows were in the morning during the breakfast period, followed by a large
decrease during the rest of the day in both flats and houses (Fox, 2008).
•
Higher proportion of occupants reported opening their windows in the morning and at night than any other
period of the day (Wouters & De Baets, 1986).
•
Houses where the housewife did not work but stayed home had twice as much windows open than houses
where the housewife was in full-time employment (Brundrett, 1977).
Household composition
•
The Belgian team discovered that households with occupants aged 18-44 years opened their
windows more frequently and for longer than those with occupants aged over 45 years old
(Dubrul, 1987).
•
A possible reason could be that older occupants are more sensitive to cold air.
•
There was no clear trend found in the relationship between household size and window
opening behaviour in the IEA Annex VIII studies.
•
A positive correlation between the number of open windows in dwellings and the household
size was found by Brundrett, 1977.
Household Activities
•
Occupants’ reported opening their windows when did household activities such as
vacuum cleaning and airing bedclothes (Van Dongen, 1986).
•
In kitchens, window opening was related to cooking activities, cooking smells and
vapour problems.
•
In the Belgian and Dutch studies a positive correlation was found between the use of
showers and the use of the bathroom windows (Dubrul, 1988).
•
Amongst occupants’ most popular reasons for opening their windows was to remove
condensation (Andersen, 2009 & Wouters & De Baets, 1986).
References
Andersen, R.V., 2009. Occupant behaviour with regard to the control of indoor environment. PhD. Technical University of Denmark.
Brundrett, G., 1977. Ventilation: A Behavioural Approach, Energy Research, pg 289-298.
DECC, 2011. Domestic energy consumption in the UK since 1970 [pdf], Available
at:<http://www.decc.gov.uk/assets/decc/11/stats/publications/energy-consumption/2323-domestic-energy-consumption
factsheet.pdf> [Accessed 18th February 2012].
Dubrul,C., 1988. Inhabitant Behaviour with Regard to Ventilation, IEA Annex VIII Report.
Erhorn, 1986. Influence of the meteorological conditions on the inhabitants’ behaviour in dwellings with mechanical ventilation. In: 7th
AIC Conference, Occupant interaction with ventilation systems. Stratford-upon-Avon, UK, 29 September – 2 October 1986.
Fox, J., 2008. A Study of occupant controlled ventilation within UK dwellings. PhD. University College London.
Garland, et al., 1993. Residential Energy Usage and the influence of occupant behaviour, Proceedings of the ASME Winter Annual
Meeting, New Orleans, Louisiana, The American Society of Mechanical Engineers.
Jacobs, et al., 2010. Window opening in High Performance Buildings. Department of Energy & Comfort Systems.
Shipworth, M., 2011. Thermostat settings in English Houses: No evidence of change between 1984 and 2007. Building and
Environment, 46(3), pp. 635-642.
Van Dongen & Phaff., 1989. Ventilation behaviour & indoor air problems in different types of newly built dwellings. Environmental
International, 15, pp. 95-106.
Van Dongen, 1986. Inhabitant behaviour with respect to ventilation. Occupant interaction with ventilation systems. Stratford-uponAvon, UK, 29 September – 2 October 1986.
Wallace, et al., 2002. Continuous measurements of air change rates in an occupied house for 1 year: The effect of temperature,
wind, fans, and windows. Journal of Exposure Analysis and Environmental Epidemiology,12, pp.296-306.
Wouters & De Baets.,1986. A detailed statistical analysis of window use and its effect on the ventilation rate in 2400 belgian social
houses. In: 7th AIC Conference, Occupant interaction with ventilation systems. Stratford-upon-Avon,UK, 29 September – 2 October
1986.
THANK YOU!
ANY QUESTIONS?