Both conductors and insulators deal with the electric conductivity of a surface or material. An item is an insulator if it inhibits current flow. They are similar in that they both deal with conductivity of materials, and they are on opposite ends of a conductivity scale.

All materials are made up of atoms. The arrangement of the atoms determines their response to electricity conduction. Materials that do not conduct electricity are classified as insulators and those that conduct are called conductors. Conductors fully allow electricity to easily pass through.

A conductor allows current to flow easily through it. An Insulator doesn’t allow current to flow through it. Electric charge exists on the surface of conductors. Electric charges are absent in insulators.

A conductor is a substance that allows charge to flow freely through its atomic structure. An insulator holds charge within its atomic structure. Objects with like charges repel each other, while those with unlike charges attract each other.

Insulators:

• glass.
• rubber.
• oil.
• asphalt.
• fiberglass.
• porcelain.
• ceramic.
• quartz.

Insulators oppose electrical current and make poor conductors. Some common conductors are copper, aluminum, gold, and silver. Some common insulators are glass, air, plastic, rubber, and wood.

The most effective electrical conductors are:

• Silver.
• Gold.
• Copper.
• Aluminum.
• Mercury.
• Steel.
• Iron.
• Seawater.

Electric Insulator Examples

• Rubber.
• Dry wood.
• Air.
• Glass.
• Dry paper.
• Plastic.
• Porcelain.
• Glass.

Wool, dry air, plastics, and polystyrene foam are all examples of good insulators. Materials that do not insulate well are called conductors. Conductors have loose bonds that allow particles to move easily and transfer energy from one particle to the next. Metals tend to be very good conductors.

Natural Fiber Insulation Materials

• Cotton. Cotton insulation consists of 85% recycled cotton and 15% plastic fibers that have been treated with borate–the same flame retardant and insect/rodent repellent used in cellulose insulation.
• Sheep’s Wool.
• Straw.
• Hemp.

Bubble wraps serve as a good insulator because of its design which has small air pockets. Because the base material for bubble wraps are plastic, it heats up quickly, and so bubble wraps serve as good insulators.

The best insulators for keeping the water hot were cotton and plastic while the worst two insulators for keeping the water hot were the aluminum foil and the bubble wrap. Overall, it was found that the best insulator was cotton while the worst insulator was the bubble wrap.

Metals are good conductors of heat. Air is a good insulator; so things which have air trapped in them, like cotton wool, sponge, fibre glass, fur and feathers, are good insulators.

Zeolite thermal storage retains heat indefinitely, absorbs four times more heat than water.

Aerogel is more expensive, but definitely the best type of insulation. Fiberglass is cheap, but requires careful handling. Mineral wool is effective, but not fire resistant. Cellulose is fire resistant, eco-friendly, and effective, but hard to apply.

Closed-cell spray foam has the highest R-value of any insulation, up to R-6 per inch. It takes up less space than fiberglass or blown-in insulation. It can also save up to $500 a year in energy costs.

Spray foam insulation

Insulation helps to prevent that transfer of heat. Many different materials are used for insulation. Engineers often use fiberglass, wool, cotton, paper (wood cellulose), straw and various types of foams to insulate buildings. A layer of trapped air can serve as insulation, too!

A conductor is a material that allows internal (thermal) energy to be transmitted through it easily. Metals, such as copper and aluminium are the best conductors of heat.

According to the EPA: “Homeowners who are exposed to isocyanates and other spray foam chemicals in vapours, aerosols, and dust during or after the installation process “run the risk of developing asthma, sensitization, lung damage, other respiratory and breathing problems, and skin and eye irritation.”

Aluminum foil, also called tin foil, makes an excellent insulator, and in some situations, it works better than materials like cotton or paper. Aluminum foil is not best for every situation, though, so using it correctly is an important part of saving energy.

Fiberglass

Rolled fiberglass insulation scores an R-value of 3.7. So overall, rolled fiberglass insulation is slightly more effective at blocking in and out heat than its blown counterpart.

Longevity: Spray foam insulation typically lasts much longer than blown-in insulation, but the longevity of your insulation can vary significantly depending on the specifics of the installation process, the material and your property.

Blow-in insulation is quite comparable in cost and R-value when compared to fiberglass batts or blankets.

It is possible to over-insulate your house so much that it can’t breathe. The whole point of home insulation is to tightly seal your home’s interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That’s when mold starts to grow.

80 to 100 years

Cost Factors Rolled fiberglass or rock wool insulation, known as batt, is the least expensive form of insulation. Spray foam and foam board are the most expensive forms of insulation and are rarely used for attic space because of the higher cost.

Unless your home is relatively new, you will almost certainly benefit from installing blown insulation in your attic. It will make your home a more comfortable place to be in summer and winter, decrease the cost of your energy bills, and increase the value of your home.

Blown insulation settles over time, becoming less effective. Over time, blown-in insulation will settle and lose these air pockets, reducing its effectiveness. The amount that your blown insulation will settle depends on the material it is made from.