Everyone knows that having single glazed windows is a disaster as far as energy usage is concerned. Many houses already have double glazed windows and one of the objectives of the government is to refurbish many more homes in the next five years so that they have more energy efficient windows. But is it always enough to have double glazing? Cold countries such as the Scandinavian countries favour triple glazed windows, with special heat conserving glass – some people in the US believe that the extra expense is also worth if for homes in this country.
Energy Efficiency with Style
The manufacturing processes and the technology involved in making double and triple glazed windows has progressed a lot in the last few years. It’s now possible to get energy efficient multiple glazed windows in any style, suitable for modern, new builds, or traditional Victorian homes or medieval farmhouses. It is crucial that the frames are airtight and let in no drafts – the glass may be energy efficient, but the window overall will be a drain on energy and on finances.
Double or triple glazed glass units for windows can be fitted in any style or material, but the main ones used tend to be wood or UVPC. There are advantages and disadvantages to both; wood may look good and fit in much better in an old house, but it does need regular maintenance to prevent weather damage and to keep it in the best condition. UVPC is available in different colours – you don’t have to have white – and it needs a clean a couple of times a year to keep it looking new.
How Much Can you Save with Double Glazing?
Various studies have been done to illustrate how an individual householder can save money with double glazing – the current estimates say it’s about $135 per year, which represents a reduction on your energy bills. Double glazing costs a lot more than that though, even for one window, so getting new energy efficient windows must also increase the look and appeal and saleability of your home. It takes many years for the windows to pay for themselves.
Triple Glazing is Usually A Rated
Although some double glazed energy efficient windows do carry the A rating, triple glazed windows are always highly rated as they have three layers of glass with internal gas filled spaces to provide much better insulation. The most energy efficient designs have krypton, argon or xenon between the sheets of glass. These are the inert gases – there is little chance that they could leak out but if they did, the gases are completely harmless.
Other rating requirements are now imposed for all new windows fitted in England and Wales as part of the governments drive to reduce energy expenditure and to lower our national carbon footprint. New windows must be rated at least at the level of band D energy efficiency but if you are changing the windows, you want them to last for years, so choosing at least a B rating is sensible.
What is Low Emissivity Glass
Also called Low-E glass, this is the most thermally energy efficient double glazing. When you have this type of glass fitted to a south facing window, you can maximise the heating effect of the sun in winter and minimise the loss of heat through the glass from the inside. The windows are made from glass that has an internal thin coating of a metal oxide, so it lets heat in but stops it getting out again. You are looking through this layer all the time, but it is so fine that your eyes can’t tell the different between low emissivity glass and ordinary glass.
Whatever type of window you choose, the most important thing for energy efficiency and cost effectiveness is to get the windows fitted professionally. They will then look good and you can be assured they will be draft free and will comply with building regulations. It’s best to look for someone who is registered with one of the UK schemes for window installers – either FENSA or Certass. That way you will also get a certificate to show the windows fulfil energy conservation requirements and you can keep this to pass on if you sell your house during the lifetime of the windows.