Green Roof Solar Absorptance

Conductance w thermal capacity kj an d solar absorptance.

Green roof solar absorptance.

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. Solar energy absorbed depends on surface color. The model has been tested successfully using observations from a monitored green roof in florida. The results show that white roof and green roof have a much lower solar absorptance than grey common roof.

Tastes great less filling. 3 it works better and costs less than adding dirt and grass. Besides to keep the green roof green you have to water it. Approximated white smooth surfaces.

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. Grey to dark grey. 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. 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.

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. 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 key property of a green roof is its low solar absorptance which causes lower surface temperature thereby reducing the heat flux through the roof. Absorb factor fraction of incident radiation absorbed.

The solar absorptance of the roof material shows the highest μ absolute mean value of elementary effects indicating a significant influence on the model s output. 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. The solar reflectance index can be used in cool roof calculations to demonstrate compliance with leed leadership in energy and environmental design a voluntary environmental certification system developed by the u s. 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.