## Calculation method and database for insulation against external noise.

Sigurd Hveem

MSc - Senior Scientist

SINTEF Building and Infrastructure

Materials and Structures

P.O. Box 124, Blindern, NO - 0314 Oslo, Norway

Phone: +47 22 96 57 23, Fax: +47 22 96 57 25

E-mail: sigurd.hveem@sintef.no

Web: www.sintef.no/byggfors k

SINTEF Building and Infrastructure has since 2008 worked on a large R&D project for a group consisting of the Norwegian pollution control autority (Statens forurensningstilsyn, SFT), the Norwegian public roads administration (Vegdirektoratet), the Norwegian national rail administration (Jernbaneverket), the Civil Aviation Administration (Avinor)/ Oslo Airport (OSL) and the Norwegian Defence States Agency (Forsvarsbygg).

The project is dealing with further development and quality assurance of the database connected to the calculation method in SINTEF Building and Infrastructure Handbook 47 “Insulation against external noise – Calculation method and database”. This is all a part of a process for transition of the Handbook 47 into an electronic, internet version where we at the same time update and qualify all the input data for the exposed parts of the building. This will be electronically published through SINTEF Building Knowledge System (BKS) / SINTEF Building Research Design Guides and, the series which is the most used planning and design tool amongst Norwegian architects and engineers. In parallel we cooperate with SINTEF Information and Communication Technology (ICT) where construction data from our database shall be accessible for their additional calculation program “Støybygg”. This program makes it possible when using prediction tools for estimating external noise levels from road traffic, railroad traffic, airports and industry plants, also to calculate indoor noise levels as an additional program module.

The database in Handbook 47 (mainly from 1999) consists of data for outer walls, windows, ventilation outlets and roofs. The calculation method was originally developedin 1988 by SINTEF Building and Infrastructure and is accordance with NS-EN 12354-3 (2000) Building acoustics - Estimation of acoustic performance of buildings from the performance of elements - Part 3: Airborne sound insulation against outdoor sound.

We are now in a middle of a process where we are performing a number of new laboratory tests in order to secure that the data in the database are of a good quality. At the same time we are completing the database with data for constructions that are not sufficiently covered up to day. The selection of need for new data has been done in cooperation with the acoustic consultants in Norway. One of the reasons for focusing on an “official” database with qualified data is that the authorities being responsible for financing rehabilitation of buildings exposed to high noise levels, wants to secure that all are evaluated in an equal manner.

We have now completed the measurements for windows and ventilation outlets. Later we hope to get financial support for the measurements of outer walls and roofs. In this presentation we will give an overview of the calculation method including some standard reference noise spectra for road traffic, railroad traffic and aircraft traffic. We will also focus on some interesting results from the latest measurements of windows and of ventilating outlets.

Concerning the windows, one main target in this project has been to establish data for typically windows with different degree of air leakages. This is especially important when one shall estimate the indoor noise levels for existing building and further evaluate the need for renovation.

Concerning the ventilating outlets we have found errors in some product data for sound reduction of common used products, overestimating the high-frequency damping due to wrong mounting in the test laboratories. We have during the last years also completed the data for ordinary, un-dampened ventilation outlets for the same reason as mentioned above for the windows. At the same time we have focused on data both for closed and open ventilator outlets because the procedure for estimating indoor noise level of existing building according to the requirements by the authorities assumes closed ventilation outlets.