Opening windows was not an issue to my grandparents. It was part of a daily routine to air the home.
Modern house building tends to create homes which are small sealed boxes for reasons of cost and energy efficiency. It can lead to poor indoor air quality and researchers say householders should be aware of the potential health impacts.
The Mackintosh Environmental Architecture Research Unit, based at Glasgow School of Art, surveyed householders in the city between September 2011 and May 2012, and discovered that 87% had dried domestic washing indoors, and 64% had done so on or near heat sources. Some (23%) turned the heat up to make clothes dry faster and 37% opened a window while drying.
Whilst Glasgow may not represent the whole of the UK it is certainly common practice to air washing on radiators or on clothes horses over underfloor heating.
Indoor drying increases moisture in the air, encouraging dust mites and leading to increased concentration of mould spores, as well as reducing the indoor air quality. Dust mites and mold spores have been linked with poor health, particularly asthma and other respiratory conditions. To counter this you can open windows and turn the heating up.
The other 2 alternatives are to dry washing outside, which has not been so easy recently, or to use a dryer which is not very environmentally efficient, and to pipe the wet hot air outside.
Alternatively you can accept a lower house temperature.
One of the report’s authors, Professor Colin Porteous, said the findings were a particular problem in Scotland, where the weather limits the opportunities for outdoor drying and air is already frequently moisture laden.
He added: “Levels of fuel poverty in Scotland are already excessive and increasing the domestic heating load during the drying process makes a bad situation worse. It is a catch-22 situation because tumble drying is more energy intensive than open window passive drying.
“People are sealing their homes more tightly to be energy efficient and more comfortable, but this is not accompanied by ventilating them adequately.”
He called for dedicated drying spaces and argues that housing providers could consider returning to the model of tower blocks which were often built with communal laundry facilities on the ground floor, or could explore the use of covered drying areas outside. New homes could be built with drying cupboards, isolating drying from the rest of the house, which contain a heating element and ventilation to remove the moisture safely, while older homes could be retro-fitted with a variety of solutions.
Prof Porteous added: “Building regulations currently require new homes to have a one-metre cubic space for drying which is not enough, and can be above the bath. That is only likely to increase the problem of moisture in bathrooms.”
The report was published with a design guide aimed at government, private and social housing providers and architects, providing technical guidance on design upgrades.
Renewable heating such as biomass boilers or heat pumps can offer a home owner the opportunity of an incentive through the Renewable Heat Incentive. This can help pay for the installation of heating and offer an alternative to oil or other fossil fuels that may well be significantly cheaper to run.
Biomass boilers can heat a home quickly and to a high temperature if needed. In other words for periods of time they can work harder when the windows are open.
What is an issue for us when doing surveys is that the home is surveyed using a methodology that does not take into account different ways of drying and to what extent the home owner likes to open their windows. On all high efficiency homes opening windows and doors is an issue and can affect your quality of life. In addition to drying your washing there are other issues such as:
- opening doors to let children play in the garden (or dogs)
- opening windows to let in fresh air in the morning
- Drying towels after baths or showers
It is clear that there is a compromise that most people work towards and even in the most efficient homes individuals will feel the need to have fresh air and not solely look to conserve heat at all costs. Whilst there are some solutions that home designers can look at that may well be currently overlooked most of us have the homes we live in and may be limited in choices available to both conserve heat and maintain airflow within a home.