Single or multi-glazed sound insulating window - reduces traffic noise to acceptable level with acoustic reduction index of 31 to 36 decibels

摘要

The acoustic window utilises standard frames, incorporates noise-insulating properties developed and tested under laboratory conditions, and is designed to reduce road-traffic noise to an acceptable level. The window has single or multiple glazing, has a superficial mass of not more than 40 kg/m2, and has a thickness of jot more than 30 mm. The acoustic reduction index (A.R.I) relative to road traffic noise and in absolute terms is between 34 and 38 dB (A) and 31 and 36 dB (A) respectively. Specific values for the A.R.I. may be 35 dB (A) and 32 dB (A) respectively. The window may be single-glazed with 10 mm thick glass, or may be doubled glazed with panes of 10 and 4 mm, thickness separated by a 6 mm. cavity. Alternatively triple-glazing may be utilised with two 4 mm. panes (1, 2) separated by a polyvinylbutyl film (3), a 6 mm. cavity (4) and a 5 mm. thik pane (5).