The walls and roof are the usual suspects when it comes to energy loss in a home but windows play a significant role too and are often overlooked when it comes to saving on energy bills. However, there are many window treatments available, not only for decoration but for energy-saving and efficiency too. Various treatments are designed to enhance heat gain in the summer and minimise heat loss in the winter, but there are many different methods for you to choose from, some of them more specialised than others.
Window blinds may be either horizontal or vertical and are more effective at reducing heat gain during warm weather than at keeping the heat in during cold snaps. The slats in interior blinds are particularly flexible and, unlike shades, they can be finely adjusted. When they are completely closed they can reduce heat gain in the summer by up to almost half.
How well your curtains reduce heat gain and loss depends on a number of factors, including the colour and fabric type, such as open or closed weave. Heat gain can be reduced by 33 per cent when you use medium-coloured curtains with backings of white plastic. When you draw your curtains in cold weather, most types reduce heat loss by up to 10 per cent. To reduce convection, or heat exchange, hang the curtains very close to the windows. It will help if you install a cornice and seal the curtains at each end and in the centre where they meet.
An insulating panel consists of a core of foam board, which can be clipped to the inside of a window, with the edges sealed against the frame with Velcro or magnetic tape. You do not need latches or hinges and the treatment is relatively cheap. The panels have R-values (a measure of thermal resistance), typically between 4 and 7.
There is a wide range of shutters available to help reduce heat loss and gain in a home. Exterior shutters can be blended in with the architecture. They need to be drilled, mounted and hinged, and they often have a mechanical crank attached. They work best as shading in the summer; solid models are most effective at this and at reducing heat loss in winter.
Insulating shutters incorporate a vapour barrier and usually a decorative covering. When they are fitted snugly against the frame of a window, an insulating space is created between the window and the shutter.
Today there is a wider choice of window treatments than ever before, and they’re not merely just for decoration. The various shutters, shades, films and blinds on the market offer a whole raft of shading and sunning options, and these not only make a room look delightful but can also have a real impact on energy bills. In today’s world of heightened environmental awareness, choosing an energy-efficient window treatment makes sense both for the individual homeowner and for the planet as a whole.