news from the BRE Group
published: 24/10/2002
This press release is over six months old and the details may have been superseded. Please contact the Press Office for the latest information.
Improving air quality in homes
A BRE-led project aims to demonstrate the use of an innovative low energy ventilation system for homes which will improve air quality and reduce energy use.
The whole house low-energy passive ventilation system uses a “supply air“ window – typically a double glazed window with an extra external pane forming an air path – in conjunction with passive stack vents.Maintaining air quality in new houses can be a challenge because they are being more tightly sealed to avoid heat loss, and so concentrations of indoor pollutants may increase – VOCs, particulates, cigarette smoke and condensation, for example.
Higher volumes of winter background ventilation are therefore needed to disperse these pollutants. But as the standard of insulation in buildings improves, ventilation heat loss becomes an increasing proportion of a building’s energy consumption.
The supply air window draws air from the outside via a vent at the bottom of the outer glazing, through the air path to enter the room via a vent at the top of the inner window. Solar gain pre-heats the ventilation air during the day, and at night a proportion of the heat lost through the inner glazing is recovered in the ventilation air.
The system is made from components that already exist, or that can be readily manufactured, and is easily installed, both in new-build and retrofit applications. “So there are no practical barriers to its implementation,” says Dr Paul Baker of BRE Scotland, who is leading the study.
“The supply air window concept was first tried in Canada and Finland in the 1970s and 1980s, but we have improved the design through a program of testing and computer modelling to optimise the existing window technology," says Dr Baker. "We are installing the system in housing association properties in Norwich, the first time the technique has been applied in Britain – although there are trials of similar systems in Denmark, Ireland and Poland."
“We are making several improvements to the original concept,” explains Dr Baker. “For example, we will use low emissivity coatings to reduce U-values and maximise heat reclaim. The window also uses innovative pressure-controlled vents that improve heat reclaim efficiency and offer a more stable ventilation rate."
The results of the demonstration will be compared with those of the European study and with previous applications of other innovative solutions, as well as established technologies such as trickle vents and MVHR.
The project will publish design guides and best practice reports on completion of this work in 2004.
On-site visits can be arranged for interested parties during the demonstration period next year.
For further information: Paul Baker, 01355 576234, E-mail bakerp@bre.co.uk
Diagrams of the systema are availabe, E-mail harveyt@bre.co.uk
For updates on the project visit the website at www.arct.cam.ac.uk/WholePVS
Funding and partners
The project is being funded under the DTI’s Partners in Innovation scheme.
The partners are:
- The Martin Centre, The University of Cambridge
- Cambridge Architectural Research Ltd
- The National House-Building Council (NHBC)
- Peddars Way Housing Association
- Titon Hardware Ltd
- Whitaker & Co Ltd
Follow BRE Group online:
