Airflow
The diagram above demonstrates that our sealing system exceeds the highest classification of 6375 Part 1 (1989). This standard is used to determin air infiltration of new windows.

The gaps in an average sash window equate to a square of 145mm x 145mm, therefore installing a sealing system is particularly significat in the control of airflow and the elimination of draughts.

Air Changes Per Hour (ach)
Our sealing system achieves the equivalent comforts of double glazing while it achieves 85% of the energy saving. The energy savings made by sealing the gaps and eliminating the draughts are significantly greater than the saving achieved by the reduction of the 'U' value of the glass.

While air changes in a house in an exposed area could range between 2.5 - 3.0 per hour, our perimeter sealing system will reduce this to 0.7 per hour giving greater comfort levels and a large reduction in energy costs.

Sound Reduction
A window with an opening of any kind needs an efficient seal to reduce noise levels. Sash Windows ideally need a gap of 3mm in order to operate correctly. This means that in an average size window the air gap would amount to 1% of the total window area.

BS8233 indicates that a gap of 1% would double the sound ingression. Our sealing system eliminates the air gap and would therefore achieve a 10db improvement in sound insulation, equivalent to a 50% reduction in noise ingression.

The installation of a double glazed 4/12/4 unit does not reduce noise levels, and in some circumstances can increase noise.