Insulation for buildings facilitates retention of energy to make it energy efficient and cost saving. Types, Materials and methods of building insulation is discussed.
During earlier periods, the buildings were constructed tremendously with no consideration for insulation mainly because of the reason of cheaper cost of energy. But now the condition is different. Buildings with no kind of insulation results in the waste of energy. This concern is now not a factor of economy alone but the need for sustainability.
An estimation from the studies conducted proves that the use of insulation in buildings helps to save the building energy costs by 10 to 20%. But the actual cost also depends on the extent of insulation the building possesses initially, how much more is to be added, the number of openings, say doors and windows. The efficiency of insulation also depends on the weather stripping.
Different Types of Insulation for BuildingsThere are different types of insulation materials available for the insulation of buildings. These includes:
- Mineral Wool
- Reflective Foils
- Various types of Foam Insulation
Fig.1: Loose Ceramic Fiber for Insulation
Fig.2: Blanket form of Ceramic fiber used as insulation
Fig.3: Modular form of Insulation
Fig.4: Industrial Insulation Boards
Fig.5: Textile form of Insulation
Considerations in the Provision of InsulationThere are certain considerations that need to be considered while providing insulation for the building. Proper insulation is an important factor for a building. The main objective of insulation is to resist the escape of building heat. The quality of insulation under consideration is represented by a parameter called as the thermal resistance factor (R). The sum of thermal resistance of entire structural elements of the building including the wood, concrete, insulations etc will provide the total thermal resistance of the building. The inverse of thermal resistance is called as the coefficient of heat transfer (U). Coefficient of heat transfer is an expression that defined the amount of heat flow through an area. This is expressed in Btu per square foot per hour per degree Fahrenheit (Btu/ft2/hr/oF). Below are the formulas used for the conversion of R to u to watts i.e. electrical units.
Thermal resistance (R) = 1 / coefficient of heat transfer = 1/ U
Watts (W) = coefficient of heat transfer / 1 = U / 3.4
Watts (W) = 0.29 x UVarious tables and formulas are provided by the manufacturers of the insulations that can be used to estimate the heat loss that is occurring in the building for different concentration. The building must be provided with enough insulation so that it will help in Reduction of heat loss. If this is not the case, the electrical heating and the air conditioning systems will be very inefficient and become uneconomical. The basic building construction and the amount of insulation used in the building will define the heat loss of the building. A concrete building has different amount of heat loss compared to a building completely made of wood material.
Installation of Insulation in BuildingsThe exterior walls and the interior walls that is located in between heated or cooler area or unheated areas must be provided with insulation. These are the common areas of a building for which the installation of insulation is necessary. The ceilings constructed in cold space regions must also own a proper insulation. The floors areas and walkways constructed above the cold space must be provided with proper insulation. The determination of thermal resistance of the building or the R-value is very essential. This valued helps in knowing how well performing is the insulation within the building. This provides an idea on how extent it resists the flow of heat within the building under consideration. The thickness at which the insulation is provided affects the R-value. Now the mineral wood batts that have a specification of R19 are 6 inches in thickness. At the same time, this is R-13 for a thickness of 3 to ½ inches. The insulation materials have specification marked on the top based on the R value in such a way that it is easily seen. General specification of insulations for different areas of the building is mentioned below:
- Floors: R-11 TO R-19 (Mainly chosen based on the climate conditions)
- Attics: R –22
- Walls: R – 13
Insulation for Duct and Pipe Area in BuildingsAnother area that is more prone to heat loss is around the heating ducts and the pipes present in the building. The installation of the insulation must be done around the heating ducts and the pipes so that the excessive heat loss can be avoided. The figure-6 below shows some of the insulation material types that are used for the insulation of ducts and the pipes.
Fig.6. (a) Insulation Wrap for Ductwork (b) Flexible Ductwork Insulation (c) Different pipe insulation sizes (d)Installed pipe installation example