How Do White Roofs Reduce Smog

By lowering energy use cool roofs decrease the production of associated air pollution and greenhouse gas emissions.

How do white roofs reduce smog.

A cool roof transfers less heat to the building below so the building stays cooler and uses less energy for air conditioning. Recently launched by the 3m smog reducing granules nitrogen oxides or nox using roofing shingles. 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. In 2017 more than 3 000 city rooftops were painted using both white lime and a special reflective coating.

Reduced air pollution and greenhouse gas emissions. 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. That would reduce la smog as much as a total ban on cars and lorries. Volunteers have taken white paint to nearly 7 million square feet of tar roofs in the city though that is still only about 1 percent of the potential roof area.

How do they work. The study however did not account for how white roofs might reduce electricity use for cooling which could help lower temperatures by reducing emissions from power plants. There are many small scale initiatives in cities to make roof surfaces more reflective. Roofs and roads are routinely repaired and replaced and.

In urban areas white roofs also help lower smog levels by lowering local temperatures which tend to be higher due to the large proportion of paved surfaces. New york for instance introduced rules on white roofs into its building codes as long ago as 2012. Improved human health and comfort. Known simply as cool roofing this process is designed to reduce the solar radiation.

Cool roofs can reduce air temperatures inside. This is not just a question of painting things white. The study concludes by stating that the rate of smog formation increases exponentially with temperature and that making the switch to white roofing would reduce smog by 10 percent in urban areas which is the equivalent of removing three to five million cars from the roads. Black roofing is also responsible for heating our waterways.

Critics have suggested white roofs do. Lawrence berkeley estimates that installing so called cool roofs and cool pavement and planting trees over 30 percent of the los angeles basin would lower the average outside temperature by five degrees which would in turn reduce smog by 10 percent.