Insulation keeps cold stuff cold and hot stuff hot. A blanket can be a good example of insulator.

A variety of materials can be use as insulation. The list includes fibrous insulation, insulated panels, foam insulation, straw panels. Other than this conventional cellulose, mineral wool and fiberglass can also be used as insulators.

Manufacturers produce high density fiberglass batt insulation. These are ideal for insulating cavity spaces like cathedral ceilings. The medium density batt have double fiberglass and high density batt have thrice fiberglass. Higher density batt is expensive. Some manufacturers offer fibrous insulation which is combination of two types of glass fibers. This new form is very comfortable over the conventional fiberglass. The random curve of the material causes less skin irritation. The strands are larger and greatly reduce the danger of respiratory disease.

There are cottage insulations available in the market. It is available in the form of batt or loose fill. The polyester, recycled cotton and nylon fibers are treated with flame retardant and insect repellant to obtain this insulation. The main advantage of this insulator is it does not cause skin irritation like conventional fiberglass. This insulation may not be readily available in some parts of country.

Another type of insulator comprises of three sub types of insulators and is generically named as mineral wool insulation. The three types consist of glass wool / fiber glass which is made from silicates or recycled glass, the second one is rock wool which is obtained from the igneous virgin basalt and the slag wool which is made from the slag of steel mill. The major part of the mineral wool in US is slag wool which is stiff and brittle. This insulation is fire resistant and has sound proofing effects. Nowadays a soft mineral wool is also available. This is compressible and hence is fit for insertion between framing members. It expands to press against the framing members that add to the insulation effectiveness. The price of this insulator is nearly 15% higher than the fiberglass. It is fragile than the fiberglass also.

Another type of insulation that can be seen in the market is the plastic fiber insulation. These batts are made up of the recycled polyethylene terephthalate (PET). This is used mainly to make milk containers. The fibers are extremely thick and are able to give the effect of high density fiberglass. Since this insulator is obtained from recycled content it has a good market value. This insulation also does not irritate the skin. It does not burn by open flame but can melt at low temperature.

Several other fibers are being tested for the prospects use as insulators. The list of such materials includes hemp, straw and wool. The two of them, namely wool and hemp are commercially available in US. Straw is kind of cellulose and has good insulating properties.

There are certain insulation foams available like Urethane foam and Nitrogen based Plastic foam. Some cement based insulations are also available along with the phenolic insulation. Many types of insulations are gaining popularity in construction.