Double Glazed Windows Improve Energy Ratings from Westech by Certainteed

Find out how the energy efficiency of uPVC frames and double glazed windows significantly improves window energy ratings

While a uPVC window frame looks just like well painted timber, or powder coated aluminium, it outperforms both in many important ways.

The energy efficiency of CertainTeed double glazed windows will reduce home energy consumption by 50 to 80%. Greenhouse gas emissions drop along with your power bills. Expect to reduce your annual emissions by at least 1 ton for the average home.

Most significantly, it is a highly insulating and robust material. It does not gain or lose heat through conduction like metals do - which is why aluminium should be used for cookware and not window frames.

Timber window frames insulate too, however timber requires regular maintenance through painting and will deteriorate without constant care.

The energy efficiency of a window is measured by a combination of factors, mainly thermal transfer - U, solar heat gain coefficient - SHGC, and air infiltration - AI.

The selection and design of frame material influences all factors. Glazing choice mainly impacts U and SHGC.

In Australia both U value and SHGC are important. A well designed home should minimise heat loss in winter while maximising the potential for free passive solar heating from the sun. In summer, heat gain should be minimised.

For these reasons, the most energy efficient windows are those where an insulating frame material like uPVC is used to support the most appropriate double glazing combination for each window according to orientation, size and room function.

An American study showed how, right from the earliest stages of manufacture, uPVC windows have less impact on the environment. *

• uPVC saves 100% of the trees used for timber windows.
• uPVC saves two-thirds of the energy needed to manufacture metal framed windows.
• Readily recycled. Even factory scrap goes back into other uPVC products.
• Because they never need painting, cleanup and disposal of paints and stains are also avoided. (CertainTeed windows are good for you as well as the environment!)