The energy consumption of a building is widely dependent on the characteristics of its envelope. Thermal insulation is a system that maintains the required temperature inside the building. The amount and kind of insulation depending on the site surroundings, geographical location & need of the project.
The theory of insulation depends on the proportion of heat loss. This occurs due to the processes of conduction, convection, radiation, or evaporation. In Buildings, Thermal insulation helps control this transfer of heat and to maintain thermal comfort.
“The goal is to minimize the heat transfer between inside and outside of building thereby reducing energy costs”
Along with the need for insulation, materials of insulation play a crucial role. Selection of material and thickness allows obtaining good indoor thermal comfort conditions and adequate energy savings. The materials used for insulation vary in Types, Forms, Applications & Materials.
Types of insulation
This type works by trapping tiny pockets of still air within its structure. This air creates provides a barrier or resistance to the heat flow.
This works by a combination of reflecting heat away from its polished metallic surface and/or by reducing the radiant heat being emitted from the surface. Because reflective insulation works by reflecting the radiant energy. Effective at higher temperatures.
Forms of Insulation:
- Slab or Block Insulation
These are in the form of boards or blocks which are made of mineral wool, corkboard, cellular glass, vermiculite, cellular rubber or sawdust, etc. It is applied to the walls and roofs to stop heat loss and keep the required temperature. They are known as blocks or boards in thickness of 2.5 cm and 60 cm x 120 cm in area.
- Batt Insulation
Insulation of walls, floors, attics, and ceilings is possible with this type as it has more thickness. It is available in pre-cut, fiberglass, or rock wool insulation form.
- Blanket Insulation
It is a widely available type of insulation. It comes in a blanket shape or paper roll. These are made up of animal hair or cotton or wood fibers etc.
- Reflective Sheet Materials
It has high heat resistance as materials used in making these sheets are aluminum, steel sheets. This is preferably outside of the structure to prevent heat from coming inside.
- Loose Fill Insulation
This is available in the form of rock wool, wood fiber wool, cellulose, etc. It is to be filled loosely in the studying spaces
- Insulating Boards
These are used for the interior lining of walls, and also for partition walls. Structural insulating boards are manufactured by first making pulp of materials like wood, cane, etc. and then pressing them in the form of boards by adding suitable adhesives. Insulation Boards are available in different sizes and thicknesses.
Commonly used Insulation Materials:
Made mostly from recycled glass, it is used in both commercial as well as residential markets. Fine strands of glass are weaved into an insulation material making it proficient at reducing heat transfer. The R-values range from R-2.9 to R-3.8 per inch.
- Easy installation
- Moisture resistant
- Non Combustibility
- Presence of Carcinogens
- Reduced lifespan of material due to settling over time
- The manufacturing process of fiberglass is energy consuming
Made from recycled newsprint, primarily available in the loose-fill form. It is used for insulating attics and can be used for walls and floors when installed with a binder, netting, or covering. With the use of recycled paper products, it is one of the top eco-friendly insulation materials in the industry today. This insulator contains almost very less oxygen lowering potential fire damage. The R-values range from R-3.1 to R-3.7.
- Treated cellulose increases fire resistance, resists mold, and makes it unpalatable to insects.
- Cellulose is generally up to 25% cheaper than fiberglass insulation
- The R-value of cellulose is higher than standard fiberglass
- Best environmentally-conscious option
- Installation costs for cellulose is higher comparatively
- Cellulose insulation creates dust when it is installed, so a certified breathing mask is mandatory.
- Cellulose insulation absorbs moisture, which not only reduces long-term efficiency
- Dry- and wet-blown cellulose need a vapor barrier.
Mineral wool is categorized into two insulation materials: rock wool, made from basalt, and slag wool from steel mills. Mineral wool is non-flammable in nature and it doesn’t require additives to make it fire-resistant. This insulation material has an R-value ranging from R-2.8 to R-3.5 and is considered as environment friendly.
- Mineral wool is naturally moisture-resistant.
- Majorly preferred for sound insulation. Sound is blocked much more by mineral wool than other materials
- Mineral wool will not burn until temperatures reach beyond 1,000°C.
- The insulation performs as a fire barrier, slowing down house fires and giving the fire services more time to get things under control.
- Protective gear must be worn when installing mineral wool insulation: the tiny slivers will lodge in the skin and are small enough to be inhaled.
- Inhaled slivers of mineral wool can cause lung disease.
- Expensive option compared to other materials of insulation
Polyurethane foams are fire-resistant and make an effective insulation material. These foams help in minimizing the risks to the ozone layer. It is used primarily to seal air leaks. These foams have an R-value of R-6.3 per inch.
- Lower cost of heating
- Quicker and easier application
- Highly adhesive to the ground, resistant to damage, and are lightweight
- It does not create any form of dust or contain allergens or harmful gases
- Expensive compared to other materials of insulation
Polystyrene is a transparent, waterproof thermoplastic insulation material. It has a distinctively smooth surface and can be cut into blocks. Being flammable, it is generally coated with a fireproofing chemical.
- Easily cut to fit into walls and ceilings
- Relatively inexpensive
- Ease of installation
- Poor chemical resistance especially to organics.
- Susceptible to UV degradation.
- Harmful to environment
- Breaks easily
A sufficiently insulated building has lower heating and cooling expenses since effective insulation minimizes heat gain during summer and heat loss during winter. Good sufficient insulation will not only help in reducing electricity bills but will help in reducing our reliance on heating and cooling systems which directly reduces the emission of greenhouse gases. It also helps in creating ideal temperatures and making the space comfortable.