Green Roof Ambient

Obviously painting roofs white increases solar reflectivity.

Green roof ambient. 4 developing a uhi strategy addressing uhi requires investment in a variety of measures including white or reflective roofs green roofs urban forests and reflective paving. Green roofs tend to maintain an ambient temperature of 90 degrees f creating optimal conditions for air conditioning. The green roof element can have a cooling effect especially in summer. In a sunny day a green roof may lower the co 2 concentration in the nearby region as much as 2.

Reduces greenhouse gas emissions. Likewise growing vegetation increases rooftop evaporation and transpiration rates and provides shade to the roof surface. A green roof makes the installation of a frame panels easier. Whereas a conventionally dark roof basically bakes on a hot summer day transmitting the heat it absorbs to the building below a green roof can remain cooler than the ambient air temperature.

If the air on the roof is made cooler by a green roof this process is easier and uses less energy. It also has a waterproofing membrane to prevent moisture from entering a building or space. 1 3 these temperature reduction and energy efficiency benefits are a key contributor to the growing popularity of green roofs in the. Green roof temperatures can be 30 40 f lower than those of conventional roofs and can reduce city wide ambient temperatures by up to 5 f.

The green roof element provides the ballast to hold the a frames and panels in place. The extent of the green roof effect is related to the condition of the plants the position of the green roof and the ambient airflow condition. Year round green roofs can help to keep ambient temperatures around the panels at or near 25 0 c. If implemented correctly green roofs can bring the rooftop temperature down to ambient which is the air temperature on that particular day.

Therefore lower air temperatures on the roof improve the efficiency of heat rejecting rooftop hvac equipment because it is operating at a lower ambient temperature. 1 2 in addition green roofs can reduce building energy use by 0 7 compared to conventional roofs reducing peak electricity demand and leading to an annual savings of 0 23 per square foot of the roof s surface. Overall green roofs such as this are considered in credits toward leed certification due to their added benefit of minimizing possible building contribution to the heat island effect in urban areas. The roof system also serves to collect condensate in its troughs which is practical in a location such as houston where a typically hot and humid climate can produce a great deal of moisture.

A green roof assembly consists of a structural deck waterproofing system membrane and associated components and overburden with plantings.