Green Roof Temperature Difference

Both techniques may partially or completely cover a roof.

Green roof temperature difference.

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. 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. 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. 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.

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. 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. 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.

Both may feature recreational facilities or commercial facilities such as a rooftop cafe. 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. The rooftop temperature results from two different properties.