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: El 230 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 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 theyVe saved fter 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 an uninsulated home a quarter of your heat is lost through the roof. There are various materials for loft insulation which all work on the principle that the best insulator is a layer of still air trapped Just above the upper loor ceilings between the timber Joists in the loft. Glass-fibre, mineral wool, polyurethane spray foam, expanded polystyrene are all suitable.
The material with trapped air is a poor conductor which reduces heat transfer from the ceiling to the loft via conduction and convection. The room in the house stays warmer for longer. The more loft insulation you install, the less heat that is lost. The optimum thickness has been shown to be 350mm, Building Regulations insist on a minimum of 270mm. Hot water tank Jacket Insulating your hot water tank is one of the easiest ways to save energy and therefore ave money. By applying a hot water Jacket to your tank will conserve heat.
Floor insulation The simplest way to insulate floors is to use a sealant to fill gaps between floorboards and around the edges of skirting boards. A more comprehensive way of insulating floors is to lift the boards and apply slabs of insulation such as mineral wool underneath. This means more disruption but is a good option if you are installing new flooring or refurbishing your home. Polyurethane Spray foam for loft Insulation Is becoming widely recognised as one of the most versatile and efficient forms of hermal insulation around, achieving excellent u values.
As the name suggests it is a a rigid foam state. It can be applied to virtually any building or structure that requires insulation. Spray foam insulation not only acts as an insulation agent but also as a wind and air barrier. As a result, the spray foam insulation and air seeling in one installation step. How much could you save? Type of Insulation Installation cost Annual Saving Payback Time Carbon dioxide Saving per year E450- E500 up to E140 Under 4 years Around 560 Kg Around E530 Around E60 Around 9 years Around 240 Kg
Around E45 Less than 6 months Around 170 Kg Solid Wall Insulation Internal E5500 to E8500 E460 Around 12 years 1. 8 tonnes External E9400 to El 3000 Around E490 Around 20 years 1. 9 tonnes Loft Insulation ( O to 270 mm) Around EBOO E180 Up to 2 years Standard Loft Insulation (100 to 270mm) up to BOO E25 upto 12 years Around 110 Kg Polyurethane spray foam for loft insulation Around E1700 to E2000 E284 Around 6 to 7 years 1000''s of tonnes These are estimates based on insulating a gas-heated, semi-detached home with three provided by the Energy Saving Trust and Websters Insulation.
Conclusion Of the methods used to insulate buildings some, are more effective than others. From my research Polyurethane Spray foam for loft insulation will save more energy than standard loft insulation but it''s more expensive to install. We can calculate the effectiveness of building insulation by looking at the initial cost and the annual saving of each method. For example the External solid wall insulation is expensive though the annual saving will be E460, it may take around 12 years before the annual savings cover the initial costs.
The loft insulation is relatively inexpensive. The initial cost may be E300 with n annual saving of E180 and the relatively short payback time is up to 2 years. After 20 years there is a saving of (20x180)-E3600 (This is 20 years savings minus the initial cost) (20x180)-300 = E3300 Whereas the Polyurethane foam insulation might cost E1700 and provide an annual saving of E284. After 20 years there is a real saving of E5680 - E1700= 3980 per year. However the higher cost of spray foam insulation is due to the fact that it is effective and long lasting.
Another key benefit of spray foam value) is significantly better than that offered by alternative materials. This means hat a lower thickness of spray foam insulation is required, compared to other insulating materials, therefore not encroaching into the space within in the building. For example, current building regulations decree that the required ''u'' value for a living space in a roof needs to be 0. 16. To achieve this, 100mm /4inches of foam is used. By contrast, to achieve an equivalent thermal value with Rockwool for instance, nearly three times the thickness of spray foam insulation, i. . : 250-280mm or 10/11 inches would be required! It also eradicates condensation, reduces extremities of emperatures, can have a sound deadening effect, is long lasting, is suitable for old and new buildings, preserves appearances, non-allergenic, and can be installed and therefore ''working'' very quickly. In conclusion, Polyurethane foam insulation is costly but effective as well as efficient. The initial installation cost is expensive but in the long run, the amount of money saved from energy saving will certainly Justify the high cost of installing spray foam insulation.
Cost- effectiveness is not the only consideration in deciding the type of insulation used or buildings. Any insulation makes the building more energy efficient. Using less energy (conserving energy) has an environmental benefit and may reduce pollution and conserve fossil fuels. Source: http://www. guardian. co. uk/business/2010/apr/13/homes-fail-energy-effciency- standards www. webstersinsulation. com http://www. energysavingtrust. org. uk/lnsulation/Roof-and-loft-insulation http:// www. frankswebspace. org. uk/ScienceAndMaths/physics/physicsGCSE/ reduceHeatLoss. htm http://www. nia-uk. org/householder/index. php? page=did-you- know-facts
No comments:
Post a Comment