How to Use WERS Screened Products
When using the WERS screened products in energy efficiency ratings it is important to utilise them in the correct way to achieve accurate glazing performance outcomes. This page gives a guide to how the simulations were performed and how to use the performance ratings in regulatory tools such as the National Construction Code (NCC) Glazing Claculator, the NatHERS programs and the BASIX tools.
How to use the ratings in regulatory tools.
To ensure that when rating a house with a screened product, using the regulatory tools for each state, you are able achieve accurate results it is important to correctly assign the performance ratings for screened and unscreened window portions. For WERS to rate the screen on specific windows it is necessary to rate the product with complete coverage of the system (pictured below).
If the window system utilised in the building is completely screened the WERS Screen performance rating for that window system can be used for the whole area.
If the window system contains screened and unscreened portions it is important to break the results into two distinct portions. It is important to apply the results of the screened window system to the screened portion of the window only. The image below shows an example of a window system with screened and un-screened portions.
When entering the performance values for the sample window system above the window needs to be broken into two main sections. The screened portion of the window system and the un-screened portion of the windows system. In order to insert these two different performance results into the regulatory tools the window system must be broken into three main sections with three different window performance inputs:
- The screened area of the window system: This portion of the window system can be input as one area with the performance values associated with the installed screen on the specific window that are available from the WERS screened product web page.
- The central unscreened portion of the windows system: This area of window is input with the performance values for the specific window from the WERS Database.
- The low light windows below the screened window area: These areas of window need to be split from the main area of unscreened window due to the different impact that shading can have on the window system. They can be inserted using the same window performance data as the central unscreened portion but if shading is applicable the height above the head will need to be associated with the top of the unscreened portion.