An insulator is something that slows down the rate of heat transfer. The amount of thermal energy escaping from a house can be reduced by using domestic insulation systems that work by reducing the effects of thermal conduction, convection and radiation. Heat insulation can take different forms depending on the type of heat transfer involved. The question arises as to which solid material is good for heat insulation. Non- metals are good heat insulators. Examples of non- metals used as insulators include wood, glass and plastics. Gases are good insulators if you can stop them moving. This prevents them from transferring heat by convection. An example of trapped gases used as insulators is a layer of air trapped by our clothing to keep us warm. The trapped air slows down the rate of heat loss from our bodies by conduction. Materials that trap air can be used in various ways to insulate buildings. . Examples are loft insulation, hot water tank, cavity insulation, double glazing etc. Why Insulate?
Home insulation costs money, not just to buy the heaters, but also to pay for the fuel that has been used. The amount of fuel we use as a nation each year to keep warm is equivalent to 30 million tons of coal. Better insulation in our homes reduce the amount of energy used to heat homes and reduce energy bills. The government has identified improving households’ energy efficiency as the best way to reduce carbon emissions at the same time as keeping a lid on rising utility bills. According to the renewable energy centre, the average house spends on average: £1230 on fuel bills each year which can be up to 50% more than necessary due to the lack of energy saving measures being implemented in the home.
According to the Energy Saving Trust in an uninsulated home: Up to 20% heat loss through doors and windows
Up to 25% heat loss through loft/roof space
Up to 33% heat loss through uninsulated walls
There are many home insulation products that can help cut down the heat loss and save money. Products such as double glazing, cavity wall insulation, draught proofing and loft insulation can be installed to prevent heat loss.
Methods of Insulation
Cavity wall insulation
According to the Energy Saving Trust (EST), one third of your home’s heat is lost through external walls. Homes that were built after the 1920s usually have cavity walls, which means there is an interior and exterior wall, separated by an air filled gap.Heat loss through walls can be reduced using cavity wall insulation. This involves blowing insulating material into the gap between the brick and the inside wall. Cavity wall insulation fills the air gap with a polymer foam. The material also prevents air circulating inside the cavity, therefore reducing heat loss by convection. So the room in the house stays warmer for longer. Solid wall Insulation
Twice as much heat is lost through solid walls, usually found in homes built before the 1920s, than is lost through un-insulated cavity walls, says the EST. You can tackle this by insulating the solid wall internally or externally, either way this could cut heat loss through your walls by 40%. External solid wall insulation is the more expensive option although it also acts as draught, weather and sound proofing and improves the look of your home from the outside. Internal solid wall insulation will cause more disruption in your home and reduce the floor area slightly, this is usually done with a stud wall or insulation boards. Loft Insulation
“We encourage people to keep their fuel bills to see how much money they’ve saved after having loft insulation installed, they are usually surprised by the savings,” says Angela Feltham, from Energy save Insulations Ltd in Bristol. According to the renewable energy centre Insulation is one of the most cost effective ways of retaining heat within a home and is part of the Governments focus towards homeowners to reduce fuel bills. Heat rises, and in...
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