Windows are a notorious point of weakness when it comes to wasted energy. You spend your money running your boiler to heat up the property, and then all that heat flies straight out of the window, then it follows that you’re going to spend even more money making up for the loss.
Of course, there are ways of limiting this damage. Among the most effective is to install new double, or even triple, glazing. You might also supplement an existing window with an additional glass or Perspex panel, called secondary glazing.
But one of the most overlooked energy-saving items are actually the curtains. These long sheets of hanging fabric do more than just look great – they also prevent the warm air inside the room from circulating near to the cooler air beside the window.
How heavy should my curtains be?
The greater the weight of fabric, the more difficult it will be for heat to pass from one side to the other. Thus a light and flimsy voile curtain will do very little to keep the energy in. A heavier one, on the other hand, will form an effective barrier. Look for curtains with a blackout lining; these will not only retain heat – they’ll also exclude light, which makes them great for bedrooms where you’re looking to sleep in, or living rooms where you’ll be watching a movie.
How much energy does closing the curtains save?
Up to a quarter of the thermal loss from your home goes out of the windows. It’s difficult to precisely measure the extent to which drawing curtains saves you money, as it requires careful laboratory conditions. One university in the UK has gone as far as to build an entire house in a sealed chamber in order to test the effects of a number of home improvements. The researchers conclude that drawing curtains at dusk will save around 15-17 per cent.
Of course, the effect of this with be different depending on where your house is, and which direction your windows are facing. North-facing windows in Australia will tend to receive more heat during the daytime, and thus curtains should be kept open throughout the day. But since there’s no possibility of solar gain after dusk, this benefit can be discounted.
Obviously, if you don’t close your curtains at night-time, you won’t save any energy at all – and thus it’s worth getting into the habit of keeping your curtains fully closed when you aren’t in the room. Over the course of months and years, this simple practice could save you hundreds of dollars, depending on how large your house is.
Measuring for Curtains
To get your curtains to hang convincingly, they’ll need to fall below the bottom of the sill, and be wide enough to gather convincingly. Use a tape measure from RS Components to measure the width of your window, and go for a curtain that’s twice as long. Remember, you want to be sure with your measurements, so measure twice and buy once!