For as far back as history goes, the earth has experienced four distinct seasons. Some areas have always experienced more extremes in terms of temperatures and therefore had to find ways to maintain a comfortable living environment. Insulation has been used throughout the centuries to keep heat in and cold out or vice versa. It is interesting to note that some of the alternate environmentally friendly techniques that are being considered today, such as fabrics, were being used in ancient times as insulation.

Defining Insulation

Broadly, the term insulation refers to a substance that slows or retards the transfer of heat or sound. Most often, when talking about insulation in modern terms, it is in reference to the building and construction industry. However, insulation is widely used in clothing manufacturing especially with winter outdoor gear. Think of down sleeping bags or hollow fiber jackets. Both down and hollow fiber are insulating materials widely used in clothing designs. Sound insulation is more commonly referred to as sound proofing. In modern-day music studios, insulation such as spray foam is used to soundproof rooms so optimum sound quality can be recorded.

Ancient Forms of Insulation

Several nations that lived in particularly hot climates would construct homes with thick walls. Thicker walls would insulate against the heat and provide a cooler and more temperate indoor environment in which to live. This is evidenced in many of the ancient Mayan ruins in Central America. The Egyptians also used these construction methods to keep out the desert heat of the Sahara. The homes were characterized by low roofs and small windows so the heat couldn’t easily enter and remain in the homes. The Ancient Greeks probably made some of the more significant discoveries in terms of insulation. With regards to building construction, they used cavity walling to insulate the buildings. Cavity walling has a gap between two walls which traps air and moderates the temperatures. In other words, during the hot summer months, the cavity walling would help keep the warm air out and in the cooler winter months, it would help keep the warmth inside the homes. The Romans also picked up on cavity walling and used it as a method to insulate their homes. In addition, they used materials such as cork to insulate hot water pipes so the heat from the pipes would not transfer to the surrounding walls and floors, causing them to crack. Fabrics were also used as additional insulation. Scraps of cloth would be tucked into window frames to keep out the desert dusk or the icy European cold. Rugs made from animal furs were used as carpets and thick linen drapes were used as curtains. Elaborate tapestries were hung on walls and helped to manage some of the moisture buildup in the stone buildings. The tapestries also helped moderate the draughts that could sometimes cause an added chill.

Industrial Types of Insulation

During the Industrial Revolution, insulation became an integral part of many designs. Steam power was driven by coal-burning furnaces and asbestos was the main type of insulation used because of its flame-resistant properties. Interestingly enough, asbestos had been used by the ancient Greeks and Romans as insulation and they had dressed their slaves in it. Even though the Greeks had noted that it seemed to cause lung disease in those who were exposed to it, the industrialists seemed oblivious to this fact. For more than a century, asbestos continued to be the main form of insulation. It was only in the mid-1970s that the harmful effects of asbestos were finally properly documented which caused industries to consider other forms of insulation. Fiberglass batting was then widely used in building and construction projects and is still used today.

The Need for Energy Efficiency

In recent decades, there has been an increasing awareness to become more energy efficient and environmentally conscious. Insulation requirements are becoming more detailed and stringent. The thinking is that better the insulation, the more energy efficient the building. Cavity walling is being reintroduced in many homes and construction projects. Other methods are also being considered for better insulation. Spray foam is a relatively new product which has entered the market. Spray foam is a chemical compound that forms foam when the components are mixed together. This foam can then be applied to a specific area using a spray gun. Once the foam settles, it expands into the area and then hardens. This forms a dense and durable insulating seal in the area. In terms of environmental consciousness, spray foam is one of the leading insulation products available on the market today.