Sound attenuation, or the limiting of sound propagation from one area to another, requires the application of special and standard insulation materials to encase or enclose the noise generating source, forming a sound barrier between the source and the surrounding area.

The purposes of applying sound attenuation materials are to:

Reduce obnoxious noise levels emitting from machines, equipment, pipe lines or enclosures.
Reduce general noise level in plant areas.
Provide for better work conditions.
Comply with noise level standards of OSHA and EPA.

There are insulations specially designed for high temperature systems – and selecting the right one should be based on the unique requirements of the system you are insulating. Be sure to examine the insulation thermal values and other performance values carefully. In addition, you may want to ask the following questions before providing an insulation recommendation:

1. What is the process?
2. What are the process temperatures?
3. What’s the process and in the exterior environment?
4. Is the piping located around people?
5. Is fire an issue?

Cold water systems require special attention because one must design for protection against condensation and consider the affect of moisture of water vapor transmission (WVT) on the insulation system.

WVT tells you how much water will be transmitted through an insulation system under certain conditions. Different insulation systems, vapor retarders and installation methods will affect the WVT of the system.

Condensation control and process control are two major reasons for insulating low temperature systems. When equipment or piping operates at temperatures lower than the ambient air, moistures in the air will condense or freeze on, or within, the insulation surface - or on the cold pipe surface. Unless the system is protected by sufficient thickness and by adequate vapor retarders, the insulation may become wet, causing corrosion, and causing it to become ineffective.

NIA has developed a comprehensive program to train certified appraisers who will have the required expertise to conduct an insulation energy appraisal and make specific recommendations to plant management.

Insulation materials usually have K-Factors less than one and are reported at what is called Mean Temperature. To determine the mean temperature, measure the surface temperatures on both sides of the insulation, add them together and divide by two.

When comparing the insulating value of different types of insulations, it's important to look at K-Factor and the mean temperature. As mean temperatures rise, so does the K-Factor.

C-Factor (Thermal Conductance Factor) - C-Factor is the number of Btus which will pass through square foot of material with 1°F temperature difference for a specified thickness. The C-Factor is the K-Factor divided by the thickness of the insulation. The formula is the reciprocal of the R-Factor formula. The lower the C, the better the insulator.

R-Factor ( Thermal Resistance Factor) - The National Commercial & Industrial Insulation Standards Manual defines R-Value as - a measure of the ability to retard heat flow rather than to transmit heat. "R" is the numerical reciprocal of C thus R=1/C. Thermal resistance designates thermal resistance values: R-11 equals 11 resistance units. The higher the "R", the higher (better) the insulating value.