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Independent Testing

Independent Testing

We improve our sash windows using our unique VPSS, which has been proven to provide improved energy efficiency.

British Standards - Independent Testing

We improve the performance of the sash window and/or casement window by installing the unique Ventrolla Perimeter Sealing System (VPSS) , which has been proven through independent testing to provide improved energy efficiency, without altering the appearance of the window.

This process ensures all the gaps around the sashes are filled, creating a fully sealed sash window or casement window. Furthermore, due to the low friction levels of the sealing system, the sliding operation of the sashes is restored to full working order.

The VPSS has been independently tested and its benefits verified by the British Board of Agrément and Acoustic Consultants Hann Tucker.

In addition, our VPSS is manufactured to British Standards (BS) 7386:1900 and is tested to British Standards 6375:1-2009; one of the most demanding European Quality Standards. The Ventrolla system exceeded Class 3, the highest level of 600Pa, which is the equivalent to 71 mph winds.

See our information on Noise Reduction for information on how the Ventrolla system can help towards noise control.

Window Energy Performance

The Ventrolla Perimeter Sealing System has been independently proven to improve the Window Energy Rating (WER) by up to 30%.

A Window's Energy Rating (WER) is made up of:

  • Thermal efficiency of the window (U-value)

  • Air permeability (air-leakage rate or air change rates)

  • Solar Gain (G-value)

View our Green Pack for more information on Home Information Packs (HIPs), Independent Testing, Building Regulations Part L1b & L2b and Energy Comparisons.