Green Roof Solar Absorptance

The first concern of the designer when addressing drainage should be to insure that the system can efficiently percolate and discharge the underflow associated with mandated design storms.

Green roof solar absorptance.

Solar energy absorbed depends on surface color. The roof solar absorptance is the proportion of the total incident solar radiation that is absorbed by the roofing material the remainder is reflected. The model has been tested successfully using observations from a monitored green roof in florida. Savings in annual energy use are just over 1 but summer cooling load is reduced by over 6 and reductions in peak hour cooling load in the upper floors reach 25.

The solar absorbance also exhibited the highest σ value standard deviation value indicating its important role in interactions with other factors followed by thickness. Conductance w thermal capacity kj an d solar absorptance. 3 it works better and costs less than adding dirt and grass. Besides to keep the green roof green you have to water it.

The key property of a green roof is its low solar absorptance which causes lower surface temperature thereby reducing the heat flux through the roof. For the newly finished taylor street storage facility in north east dc a 17 500 square foot green roof with fully integrated solar panel arrays showcases a value stacked elegant design that provides both a cost effective solution to stormwater management without forfeiting the solar panels that generate income via federal tax incentives and dc s superb solar production based financial incentives. As noted in the draft astm standard standard guide for selection of roofing waterproofing membrane systems for vegetative green roof systems vegetative roof systems can be adversely affected by either excessive or insufficient drainage capacity. 29 figure 3 2 3d mo del of rinker hall s aiz et al 2006 compared common flat roof white roof and green roof by three characters.

Tastes great less filling. Perhaps that is why some folks now call them vegetative roofs 2 if energy is your deal add more insulation to your roof and install a reflective membrane and be done. A roof with a lower solar absorptance will reflect more heat than a roof with a higher solar absorptance and will keep the roof space and dwelling cooler on a hot day. Approximated white smooth surfaces.

Grey to dark grey. This green roof module allows the energy modeler to explore green roof design options including growing media thermal properties and depth and vegetation characteristics such as plant type height and leaf area index. Absorb factor fraction of incident radiation absorbed. The results show that white roof and green roof have a much lower solar absorptance than grey common roof.