Green Roof Temperature Difference

At this level above the roofs there was hardly any temperature difference between green roof and white gravel t dif especially for the dry green roofs.

Green roof temperature difference.

The ability of the material to reflect the sun s energy back into the atmosphere called solar reflectance and the amount of heat the material rejects instead of absorbs called thermal emittance both are measured on a scale from 0 to 1 with higher scores translating into cooler roofs. 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. 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. For instance in a comparison study it has been proved that the indoor mean air temperature reduced by using green roofs about 2 6 2 and 1 4 c for athena la rochelle and stockholm respectively.

Comparative studies show that effect of green roofs on air temperature is more significant in hot climate. A roof garden is a similar technique that places container gardens on a roof. Green roofs have excellent noise attenuation especially for low frequency sounds. A green roof is the practice of growing vegetation directly on a roof over a waterproof membrane.

Green roofs can increase a building s marketability. An extensive green roof can reduce sound from outside by 40 decibels while an intensive green roof can reduce sound by 46 50 decibels peck et al. The rooftop temperature results from two different properties.