Navigating Urban Heat: How Smart Surfaces Offer a Cool Solution

Communities across the nation are experiencing an increase in extreme heat, floods and other natural disasters each year due to global warming and climate change. This contributes to increased air pollution and negative health outcomes such as respiratory illness, allergies, heat-related illness and infectious disease. For urban communities, where dark, non-porous surfaces dominate the landscape, this is a particular problem as the heat or flood waters become trapped and lead to worsening air pollution. 

So, what can we do to address this problem? New cutting-edge technologies called Smart Surfaces may be the answer. These light-colored, reflective, and green surfaces combat extreme heat and create cooler, more livable environments. Here is what you need to know. 

Why Are Cities Extra Polluted?

Unlike rural areas, U.S. cities pack together structures that absorb heat. In fact, on average, 66% of the surface area in U.S. cities consists of roads, parking lots and roofs. Cities also tend to lack natural landscapes like forests of trees, grassy areas and bodies of water. Because of this, urban areas become “heat islands,” trapping heat and causing 1-7°F higher temperatures during the day, and 2-5°F higher temperatures at night than in the country. 

Additionally, the inability of these structures to absorb rainwater means that the run-off goes directly into the sewer system, which if overwhelmed, can overflow into lakes and rivers, and contaminate the water with harmful pollutants. Drinking contaminated water can cause many adverse health effects including gastrointestinal pain, reproductive problems, neurological problems and even lung disease. 

Dark surfaces, like roads, parking lots and roofs, do not reflect the sun. Instead, they absorb sunlight which increases the surrounding air temperature. As a result, the buildings next to these dark surfaces use more energy for air-conditioning and contribute to overall urban hot spots and increased ground-level ozone. Ozone, also known as smog, causes swelling and irritation of the lungs. Immediate irritation can cause wheezing and coughing and shortness of breath. With repeated exposure, ozone can permanently damage lung cells. For those dealing with a chronic lung disease like asthma or COPD, heat and smog may trigger an asthma attack, severe COPD symptoms or lead to a lung infection.  

Reducing Heat in Cities

Smart Surfaces is the term used to encompass a suite of technologies that can help reduce heat in our cities. These include reflective (cool) roofs and pavements, green roofs, trees, solar photovoltaics (PV), greenspaces and rain gardens. Incorporating light-colored porous roads, parking lots and driveways can improve drainage and reflect sunlight instead of absorbing it, thereby reducing heat. Adding solar panels to roofs not only provides shade and discourages heat absorption, but it also can convert sunlight into electricity.   Designed to mitigate urban heat, enhance air quality and improve health, the addition of these transformative urban features can make cities more resilient and vibrant. Besides being able to cool cities by 5°F, Smart Surfaces can also reduce flooding and provide economic benefits to cities. 

One easy and effective way to reduce ground-level ozone is to incorporate trees, green roofs and greenscapes in urban settings to reduce temperatures and improve health. Here are just a few benefits of greenspaces:

• Green spaces deflect sunlight, reducing the harmful effects of direct sunlight.
• Trees cast shade that can provide a cooling effect.
• Green spaces like trees, green roofs and parks absorb air pollutants and reduce ozone levels. This can improve overall air quality and reduce respiratory distress for anyone with chronic illness.
• Green roofs reduce energy use by insulating buildings and cooling roofs. They also filter water runoff and improve water quality. 

Dale Howey manages 12 multi-unit housing buildings in the Minneapolis area that are using these smart surfaces including 310,000 watts of solar panels up or in process, heat pumps, white reflective roofs, reflective coatings on windows for heat reduction and privacy, and new energy efficient doors and windows. Not only do these surfaces reduce heat they also have benefits for the tenants. “My tenants are coming to me saying ‘I barely have an electric bill.’ Tenant electric bills are ridiculously low, typically under $10 per month. Dale’s energy bills are non-existent.” Dale explained.

But Dale and his company, Green Rock Apartments, have been halted from implementing more Smart surfaces like porous pavement because of city ordinances. “We are working on two pilot patches to solve the pavement problem; one is crushed rock and one is a porous mat made of recycled plastic that is covered with vegetation. But we need the city to change their policy which currently requires the use of asphalt or concrete in parking lots which both contribute to excessive urban heat and the environmental health problem,” Dale explained.

Policymakers and individuals can make our communities more livable, reduce heat and air pollution and improve our lung health with smart surface choices. Learn how you can get involved.