Use Radiant Barriers in Attics Radiation heat transfer from the underside of the roof to the surface of the ceil can be cost-effectively reduced by lining the surfaces with shiny low-emissivity material. Radiant barriers are frequently placed on underside of the roof rather than the top of the ceiling so that dust does not gather on the surface and reduce the efficacy of the radiant barrier. Source: ORNL Use High Levels of Ceiling Insulation U.S. Department of Energy recommended levels of insulation are shown below. Source: http://www.energysavers.gov/tips/insulation.cfm In colder climates, the recommended ceiling insulation is up to R = 60 hr-ft2-F/Btu. R=60 insulation requires about 18-inches of fiberglass or blown insulation. To accommodate this much insulation, builders use special roofing details such as those shown below that raise the roof to accommodate the insulation. Photos: NREL Green Roofs Roofs can be covered with soil and vegetation to create a roof”. “green Thermodynamically, green roofs: have solar absorptivity than black roofs add thermal mass, which reduces peak cooling and heating loads allow evaporation from the vegetation, which cools the roof. In addition, green roofs store and evaporate rain water, which decreases peak flow through a city’s storm sewer system. Green roofs may also create a pleasant space for building occupants, especially in urban environments where garden and lawn space is limited. Because of the density of buildings in highly urban areas, lower roof-top temperatures contribute to a lower air temperature for the entire city.
Use Radiant Barriers in Attics Radiation heat transfer from the underside of the roof to the surface of the ceil can be cost-effectively reduced by lining the surfaces with shiny low-emissivity material. Radiant barriers are frequently placed on underside of the roof rather than the top of the ceiling so that dust does not gather on the surface and reduce the efficacy of the radiant barrier. Source: ORNL Use High Levels of Ceiling Insulation U.S. Department of Energy recommended levels of insulation are shown below. Source: http://www.energysavers.gov/tips/insulation.cfm In colder climates, the recommended ceiling insulation is up to R = 60 hr-ft2-F/Btu. R=60 insulation requires about 18-inches of fiberglass or blown insulation. To accommodate this much insulation, builders use special roofing details such as those shown below that raise the roof to accommodate the insulation. Photos: NREL Green Roofs Roofs can be covered with soil and vegetation to create a “green roof”. Thermodynamically, green roofs: have solar absorptivity than black roofs add thermal mass, which reduces peak cooling and heating loads allow evaporation from the vegetation, which cools the roof. In addition, green roofs store and evaporate rain water, which decreases peak flow through a city’s storm sewer system. Green roofs may also create a pleasant space for building occupants, especially in urban environments where garden and lawn space is limited. Because of the density of buildings in highly urban areas, lower roof-top temperatures contribute to a lower air temperature for the entire city.