Author: Haroon Khalil

It is a granulated insulation material mixed with cement. The quantity of cement used in such materials is to provide enough strength and have sufficient pores. The coefficient of absorption varies from 0.15 to 0.30.

Common building materials are absorbents of different levels. Such materials are called as absorbent materials. Table 28.3 Acoustics level and reverberation time Table 28.4 Optimum reverberation time for closed area Qualities of a good acoustical materials are as follows: Some of the acoustical materials are discussed below.

The acoustical design of an enclosed space is basically depend on the behaviour of the reflected sound. Due to the reflection of sound two main defects are developed, viz., echoes and reverberation. 1. Echoes Echo is said to be produced when a reflected sound wave reaches the ear just when the original sound from the…

The behaviour of sound plays an effective role in the acoustical design of different types of buildings and in the sound insulation process. A sound originating from a source, such as music or operation of machine, is transmitted through the medium in all directions. The transmitted sound strikes on some surface, like wall, ceiling, floor…

Sound can travel through some medium like air. It can not travel in vacuum. Thus for the sound to be audible to the ears, the sound source and ear must be connected by an elastic medium like air. The characteristics of audible sound are discussed below. 1. Frequency of Sound Frequency of pitch of sound…

Sound is produced when part of the atmosphere is compressed suddenly. It is transmitted in the form of waves. The waves are a series of compressions and rare factions created in the air medium. The average sound travels at a speed of 340 m/s at ordinary temperature. It depends on the medium through which it…

Based on the causes of heat transfer, the areas to be concentrated for heat insulation accordingly the methods to be adopted are: 1. Thermal Insulation of Roofs The insulation can be done on outside or inside of a roof. Generally it is better to put a thermal insulation above the slab. Following methods may be…

Good insulating material should possess the properties such as adequate fire-resistant, termite resistant, moisture-resistant, adequate strength and stability and long life. Some of the insulting materials which are in use are: 1. Blanket Insulation Blanket insulators are flexible fibrous materials supplied in rolls or otherwise. They are made out of mineral wool, processed wood fibre,…

Based on the causes identified for heat transfer, the following general principles govern the thermal insulation:

Following are the factors which contribute for transfer of heat: