Oct. 17, 2012

Choosing windows to reduce noise and heat transfer...

Most of the time people want better windows to make their house warmer in winter or to stop the heat from coming in during summer. But what about the noise that is coming through the windows? Is it possible to have the best of both worlds - windows that reduce noise and keep you warm/cool? The short answer is yes it is possible, but not all glazing that helps keep your house warmer/cooler is good at keeping it quieter.

 

Keeping noise out

Windows that reduce noise transmission need good sealing, mass and stiffness. For example aluminium-framed windows with thick laminated glass work well. For double glazed windows, it is ideal to have a large (100- 200mm) air gap between the panes. It is also better to use a different thickness or type of material for the second pane.

 

Keeping heat in (or out)

Windows that reduce heat transmission need good sealing, low thermal conductivity frame and glass with Low Emissivity(Low E) coatings. An example is a timber framed window with Low E coated glass. If double glazed it is best to use a small air gap between the panes. (the opposite of what works best for reducing noise transmission) Use a tinted glass with a low E coating if you want to reduce the amount of heat coming in. You can find more information about window thermal performance on the WERS website.

 

The Best of Both

To reduce both noise and heat transmission use at least one pane of laminated glass with a Low E coating in a timber frame. If the window is double glazed use panes of different thickness. Unless noise reduction is the main objective, use a small air gap between the panes. Use a tinted glass with a low E coating if you want to reduce the amount of heat coming in.

 

Retrofitting Existing windows.

What can I do about existing windows? First thing is to make sure that your windows are adequately sealed. There are ways to retrofit seals to most types of windows and this is an effective way of reducing both draughts and noise in your house. These seals are usually available at your local hardware shop. Another option is to retrofit a second pane to the window frame to form double glazing. Barrett House at Randwick has examples of retrofitting and can be visited on regular open days.


Adding a second pane of glass will have the greatest effect on noise reduction if it is different from the first pane. The difference could be thickness, stiffness or material. This could be done with laminated glass as it has extra stiffness, or acrylic which is a better insulator than glass and has a different stiffness. There are commercially available systems to install a second pane inside your existing windows including Magnetite (sheet of acrylic held on with magnetic strip) or Euro Glazing.


Take your time in selecting the right windows for your home as they are an important investment in your house design. Knowing what to look for in windows can ensure that you live in a quieter more comfortable home.


Written by David Winterton and John Caley from Ecological Design - a sustainable building consultancy that provides independent sustainable building design advice and consulting services.

2 comments

  • double glazed window avoid heat and sounds also it is available in low cost coat. this is nice information.http://www.imperialaluminium.com.au/

    jashan sumra
  • Thank you for the excellent article.

    Further to your mention of Retrofitting Existing Windows...

    The alternatives you mention ar Secondary Glazing- provided by adding a second internal pane of glass or acrylic.

    These options are not as good as true double glazing, which provide a vacuum or argon gas-filled gap between the planes.

    There is now a TRUE double glazing retrofit option- a real double glazing unit that retrofits to existing frames.

    Obviously, the existing frames have to be in good condition for this to be viable.See details at twinglaze.com.au

    John Payne

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