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.

Green roof temperature difference.

The rooftop temperature results from two different properties. At this level well prospering gr4 still showed a slight warming effect during the day with highest average value reaching 0 5 c in the morning. Comparative studies show that effect of green roofs on air temperature is more significant in hot climate. Green roofs have excellent noise attenuation especially for low frequency sounds.

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. 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. 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. 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 temperatures can be 30 40 f lower than those of conventional roofs and can reduce city wide ambient temperatures by up to 5 f. Green roofs can increase a building s marketability. Both may feature recreational facilities or commercial facilities such as a rooftop cafe.