NAP ACOUSTICS SOUTH EAST ASIA PTE LTD
DESIGNERS & MANUFACTURERS OF NOISE AND VIBRATION CONTROL PRODUCTS

FLOWLINE Acoustic Louvres

Introduction

The design of commercial and industrial plant rooms invariably requires the passage of large volumes of air; air that is used for cooling, for consumption by engines or compressors and for ventilation or air conditioning.

In many installations, this air flow is created by noise generating equipment and the designer or engineer is faced with the problem of allowing the air to get in and at the same time preventing the noise from getting out of the plant room.

This criterion is often quite important, particularly when a low pressure drop is required and significant acoustic performance is necessary to minimize noise annoyance. When one also considers that the architect will generally require an attractive, practical solution at low cost, then it is simple to understand why the NAP Flowline Acoustic Louvres are so popular.
Description

NAP Flowline Acoustic Louvres are designed for easy installation and for applications where space is limited and to provide a superior acoustic performance and low regenerated noise levels under a wide range of operating conditions. Aesthetically pleasing, they consist of fabricated metal louvre blades with acoustic infill, alternated with air gaps and fitted into a four sided metal case. The open area of the louvre has been carefully optimised for maximum air flow and acoustic performance and the entry to each airway is streamlined for low resistance. The air flow and pressure drop characteristics, excellent acoustic performance and balanced proportions of NAP Flowline Acoustic Louvres makes them popular with architects and engineers. Long life and freedom from maintenance are assured by the use of galvanised sheet steel or aluminium sheet and inert non-combustible acoustic infill. The acoustic and airflow performance of these louvres are guaranteed and supported by independent test results.

Application

Because of their excellent noise reduction capability, NAP Acoustic Louvres can be used in almost any situation which must permit the flow of air, but control noise. The modular design and wide range of sizes and finishes allows them to be used in most industrial or commercial projects. They are ideal for use in any of the following applications:

  • Plant room ventilation
  • Cooling towers
  • Fresh air intakes
  • Compressor houses
  • Power stations
  • Electrical transformer houses
  • Ventilation exhaust plenum chambers
  • Diesel generator sets
  • Car park fan housings
  • Air conditioning plants
  • Refrigeration plants
  • Process air intakes
  • Naturally ventilated areas

FLOWLINE Models

NAP Acoustic louvres are available in two models, S-Line (Slimline) and H-Line (High performance louvre) and each model is available in depths of 300mm or 600mm.
600 S-Line Louvre
S-Line
The specially designed, low profile blades, are set at a pitch of 150mm and at an angle which prevents line-of-sight through the louvre, resulting in an enhanced high frequency acoustic performance and an extremely low pressure drop.
600 H-Line Louvre
H-Line
The specially designed, substantial blades are set at a pitch of 300mm and provide a superior low frequency acoustic performance in the critical 125 Hz and 250 Hz octave bands.

Standard Construction: The case sides are fabricated from galvanised sheet steel. The specially designed acoustic louvre blades of the "300" models are sheathed with galvanised sheet steel on the top (outward) face for weather protection and incorporates a raised lip which prevents the ingress of water: the bottom (inward) face is sheathed with perforated galvanised steel sheet for maximum sound absorption. The acoustic infill of the louvre blades is inert and non combustible and is retained so that particle fatigue or corrosion does not occur. A bird guard, manufactured from 25mm square galvanised wire, can be supplied fitted to the rear face of all models, if required.

Aluminium Construction: S-Line and H-Line louvres can be supplies manufactured from aluminium sheet, although the perforated metal bottom of the louvre blades remains in galvanised sheet steel.

Finish: NAP Acoustic louvres are usually supplied unpainted, but, if requested they can be supplied prime painted, ready for finishing on site, Special projects often require special finishes and the NAP aluminium acoustic louvres can be supplied in plain or anodised aluminium finishes, including Bronze, Grey, Gold, Navy Blue, Black and Pillar Box red. These are fast non-fade Australian standard grade colours that have particularly good corrosion resistance.

Acoustic Performance

The acoustic performance of NAP flowline acoustic louvres has been measured in accordance with the American Standard ASTM E336-67T, section A2.3 "Test procedure for measuring transmission loss in non laboratory like configurations" by an independent Australian test laboratory. Performance graph

Noise Reduction

Noise Reduction (dB)
  Octave Band Centre Frequency (Hz)
Model 63 125 250 500 1k 2k 4k 8k
300 S-Line 7 9 11 16 19 23 24 21
600 S-Line 7 11 14 23 33 43 44 40
300 H-Line 9 13 15 17 20 19 21 21
600 H-Line 9 14 22 27 33 33 30 27

Copyright © 1999 NAP Acoustics South East Asia Pte Ltd. All rights reserved.
Information in this document is subject to change without notice