There continues to be a good deal of interest in radiant barriers. A radiant barrier can best be described as being like a mirror. There are different materials, but essentially it is made with a shiny aluminum foil exterior skin. Newer radiant barrier material has a higher reflectivity than some earlier materials.
Because it is like a mirror, the radiant barrier reflects infrared radiation. It has a low emissivity — the ability to send forth radiant energy compared to that of a black body at the same temperature and with the same surface area.
So the radiant barrier does not absorb or emit long-wave radiation. What this means is that if the heat on a building is reflected away, it can’t build up inside the house. There is a difference between the use of a radiant barrier and insulation, although they perform essentially the same function. They both reduce heat flow, therefore heat buildup, into and out of a structure. The big difference is that insulation absorbs infrared radiation; radiant barriers reflect it. Radiant barriers are but one strategy, along with others, that, when used in conjunction with another, can yield substantial savings. There are many considerations when someone wants to build a new home. It is easier to add energy efficiency to new construction than to add it to an existing house. Here are a few things that can be considered for reducing energy costs.
The location and positioning of a home on the building site is important. This positioning is in relation to the seasonal paths of the sun which can help make a home more efficient. The use of landscaping, trees, shrubs and other shade treatments can help reduce energy costs. The size and position of windows and their insulating value and glazing, along with other reflective or absorptive coatings help to minimize the number of dollars spent on home energy needs.
The color of roofing and whether it has any reflectivity can help. The type of insulation and amount can most certainly affect energy use. Doors usually have a very low insulation value and are another item on the list. Air infiltration, inefficient heating and cooling systems along with inefficient appliances also contribute to utility bills. As you can see, a number of items can add up to energy savings or loss.