This article was updated on the 31st October 2018.
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Heat flow in homes can be controlled using insulation, and heating and cooling expenses can be considerably reduced if the heat flow resistance provided by an insulation material is high. Effective insulation also significantly improves the comfort level.
Heat flows by conduction, radiation, and convection, and the most commonly used insulating materials perform by reducing the rate of conductive heat flow.
The resistance to conductive heat flow of an insulating material is rated or quantified in terms of its thermal resistance (R-value). The insulating effectiveness of an insulating material will be high if it has a higher R-value, and the R-value depends on the type of insulation, its density, and its thickness.
In addition to R-value, indoor air quality effects, embodied energy, recycled content, life cycle costs, and ease of installation are other factors that should be considered to select the best insulation.
Different Types of Insulation
Many types of insulation are available, including the following:
- Blanket insulation is the most widely used type of insulation, and it is typically available in the form of rolls or batts. It is used in floors and ceilings, and unfinished walls, including foundation walls.
- Concrete block insulation is another type of insulation where concrete blocks used for walls and home foundation are insulated with different insulating materials. They can be used in walls, unfinished walls, and for new construction or major renovations.
- Foam board or rigid foam can be employed to insulate any portion of a home, from the foundation to roof. It is an effective insulation method in interior sheathing for basement walls, exterior wall sheathing, and special applications like attic hatches.
- Insulating concrete forms (ICFs) are primarily forms for poured concrete walls with a very high thermal resistance, typically around R-20. They are used in unfinished walls and in foundation walls for new construction.
- Loose-fill and blown-in insulation involves using small particles of foam, fiber, or other materials to form an insulation material capable of conforming to any space without causing disturbance to finishes or structures.
- The use of radiant barriers and reflective insulation systems reflects the radiant heat away from homes. Radiant barriers are typically used in attics, and reflective insulation integrates radiant barriers into insulation systems. These insulation systems are used in floors, ceilings, and unfinished walls.
- Rigid fiber or fibrous board insulation is composed of mineral wool material or fiberglass and is predominantly used to insulate air ducts in buildings and in places that require insulation that is capable of withstanding elevated temperatures.
- Sprayed-foam and foamed-in-place insulation are liquid foam insulation materials that can be poured, injected, sprayed or foamed-in-place. They are used in unfinished attic floors, open new wall cavities, and enclosed existing wall.
- Structural insulated panels (SIPs) offer superior and homogeneous insulation compared to conventional construction techniques. These prefabricated insulated structural elements are widely used in roofs, floors, ceilings, and building walls.
Materials Used in Insulation
A wide range of insulation materials is available, including fiberglass, mineral wool insulation materials, cellulose insulation material, natural fiber insulation materials, and much more.
Fiberglass is the most widely used insulation material in loose-fill and blanket insulation. It is also used in duct insulation and rigid boards. Manufacturers are now involved in the production of medium- and high-density fiberglass batt insulation products, which exhibit R-values slightly higher than the standard batts.
Mineral Wool Insulation Materials
Mineral wool consists of 75% post-industrial recycled content on an average. Additional chemicals are not required to make this insulation material fire resistant. Mineral wool is widely used in loose-fill and blanket insulation. The two types of mineral wool include rock wool and slag wool.
Cellulose Insulation Material
Cellulose insulation uses recycled paper products, predominantly newsprint. It is employed in both existing and new structures, as densely packed in building cavities like cathedral ceilings and walls and as loose-fill insulation in open attic installations. It is also used in new constructions by damp-spraying or installing dry behind netting. The R-value of cellulose insulation is in the range of 3.6 -3.8 per inch.
Plastic Fiber Insulation Material
The main raw material for the manufacture of plastic fiber insulation material is recycled plastic milk bottles. Like high-density fiberglass, the fibers are produced into batt insulation. Treatment with fire retardant imparts fire resistance to the insulation, but the insulation does melt upon exposure to flame. The R-values differ with the density of batts that vary between R-3.8 per inch at 1.0 lb/ft3 density and R-4.3 per inch at 3.0 lb/ft3 density.
Natural Fiber Insulation Materials
Natural fibers, such as hemp, straw, sheep’s wool and cotton, can also be used for insulation. Cotton insulation is nontoxic but involves high insulation costs compared to fiberglass batt insulation. The R-values of cotton and sheep’s wool is R-3.4 and R-3.5 per inch, respectively. The boards made from straw can also be used as sound-absorbing panels while making interior partitions.
Polystyrene Insulation Materials
Polystyrene is widely used to produce concrete block insulation, beadboard or foam board insulation, and a kind of loose-fill insulation composed of small polystyrene beads. Expanded polystyrene (EPS), Molded expanded polystyrene (MEPS), and extruded polystyrene (XPS) are some of the polystyrene insulation materials available on the market. The R-values relies on the density of the material and is in the range of R-3.8 to R-5.0 per inch.
Polyurethane Insulation Materials
Polyurethane is a type of foam insulation material consisting of a low-conductivity gas within its cells. The R-value of this insulation material is in the range of R-5.5 to R-6.5 per inch due to the gas’ high thermal resistance. It is supplied in closed-cell and open-cell formulas.
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Open-cell foam cells have a low density and contain air, which imparts the insulation material a spongy texture and a lower R-value. Conversely, the closed-cell type has a high density and contains a gas, which allows the foam to expand to fill the surrounding space.
Polyurethane insulation is supplied as a rigid foam board and liquid sprayed foam. It is also available as laminated insulation panels with different facings.
Other Insulation Materials
Other insulation materials include:
- Polyisocyanurate insulation materials
- Vermiculite and perlite insulation materials
- Urea-formaldehyde foam
- Cementitious foam
- Urea-formaldehyde foam
- Phenolic foam
- Insulation facings
Building Insulation Material Manufacturers
BASF is a major company producing a wide range of insulation products, including Styrodur® C XPS, Neopor® EPS, and Elastopor® H and Elastopir® rigid polyurethane foams.
Covestro, formerly Bayer MaterialScience, manufactures intelligent insulating materials, including Baymer® and the Desmodur® products. Insulating panels, spray foam insulation, and floor insulation are some of the products offered by Covestro.
Demilec is one of the largest spray foam insulation manufacturers in North America, supplying both open-cell spray foam insulation products, such as Demilec APX, Agribalance, and Sealection 500, and closed-cell spray foam insulation products, such as Heatlok Soy 200 Plus, Geolok, and Barnseal.
Saint-Gobain provides an extensive range of insulation products, including fiberglass blow-in insulation, reinforcements, and HVAC products, innovative vapor retarder technology, fiberglass insulation batts and rolls, and reinforcements and HVAC products.
Dow Corning supplies high-performance insulation products, such as Dow Corning® Architectural Insulation Modules and Dow Corning® Building Insulation Blanket.
In a global building thermal insulation materials market report for 2017-2021 by Technavio, the top five leading vendors are BASF, Knauf Insulation, Owens Corning, Paroc Group, and ROCKWOOL International.
Large players in the market are keenly focusing on M&As to nullify the threat of rivalry. Major players can drive down the market prices when their costs are lower than those of their competitors. The larger vendors seek to collaborate with small players to penetrate into multi-regional markets and optimize production through economies of scale.
Hitesh Bhatia, Research Analyst, Metals and Minerals Research, Technavio
BASF produces numerous materials for thermal insulation of roofs and wall applications and usually supply these materials under the Styrodur and Neopor brands.
Unlike BASF, which has a diversified its industries, Knauf Insulation focuses on the manufacture of thermal and acoustical glass mineral wool insulation only. They supply insulation for residential, commercial and marine applications.
Owens Corning, which usually manufactures glass fiber reinforcement, also offers thermal insulation foams for wall and roof applications.
Paroc Group is currently the leading manufacturer of energy-efficient insulation solutions globally, offer a variety of insulation materials. They specialize in building insulation for residential and commercial buildings, marine and offshore insulation, technical insulation and sandwich panels.
As the name suggests, ROCKWOOL specializes in the manufacture of stone wool insulation products for roof insulation. They supply for residential, commercial and industrial projects both on and offshore.
Insulation should be applied in compliance with the associated building regulations, both when applied retrospectively and when deployed during construction. Building regulations should be followed for all types of insulation, including loft insulation, cavity walls, solid walls, and floor insulation.
Building services compliance guides are also available for insulating vessels and pipe ducts. Planning permission is generally not needed for fitting insulation if there is no modification in external appearance.