In the face of the continued climate crisis, cooling the planet should be a global priority. Often, however, environmental solutions seem too complex or costly, as well as difficult to implement on a personal or global scale.
But what if cooling and energy reduction were simple? So simple that one, cost-effective installation could reap years of benefits and savings.
The answer lies in passive cooling: the reduction of heat through maintenance strategies rather than energy consuming processes.[1]
Cool roofs and the coatings used to “make a roof cool” represent one such example of this simple passive cooling technology.[2] Once installed, reflective roof coatings cool homes without any extra steps, minimizing the active energy produced through air conditioning or other cooling methods. Cool roof coatings can lead to long-term payoffs in both energy reduction and savings.[3]
What is a Cool Roof Coating?
Cool roofs work against the “urban heat island” effect, the concept that heat becomes trapped due to dense urban development.[4] To combat this unnatural effect, cool roof coatings reflect solar radiation back into the atmosphere, leading to less energy absorption and entrapment.[5] These coatings help to reduce heat in entire cities, as well as within singular homes and buildings.
Cool roofs began with the simple idea that white roofs prove cooler than dark colored roofs–just like the idea that a white t-shirt will keep you cooler than a black t-shirt.[6] Rooted in this simple science, cool roofs offer a sustainable and cost-effective alternative to the regular roof. Since 2014, Los Angeles has even required cool roofs for all new residential construction projects.[7]
Buildings with cool roof coatings experience decreased home temperatures, lower energy and air-conditioning costs, and increased energy efficiency.[8] These reflective roof coatings represent an affordable and efficient investment for both personal homes and company or corporate buildings, and one that will more than likely pay for itself and more in the long run.
How Do Cool Roof Coatings Work?
Cool roof coatings can be added to most roofs, including to steep-slope and low-slope roofs.[9] Cool roof coatings can essentially be applied similarly to paint on top of the already existing roof.
Cool roof coatings work by increasing reflectivity and decreasing solar ray absorption and are rated on the Solar Reflective Index (SRI), a measure of a roof’s ability to reflect solar rays.[10] Roofs with a higher SRI represent a more reflective roof coating and thus a more effective system. Compared to traditional roofs, roofs with cool roof coatings can reduce heat absorption by up to 80% by increasing reflectivity and solar resistance.[11]
Several types of cool roof coatings exist, with both acrylic and polyurethane systems offering effective cooling techniques.[12] Benefits of acrylic roof coatings include high reflectance, resistance to moisture and UV rays, and ease of application. Acrylic cool roof coatings are both efficient and cost-effective and can even be installed with as little as a brush.
Those looking to enhance the roof with color or stylish finishes, may opt for polyurethane roof coatings. This type of coating is also highly durable against the elements, UV rays, and moisture, providing a strong, protective coat.
What Chemicals are Used to Create a Cool Roof Coating?
To create a cool roof coating, resin, color, additives and extenders are combined through chemical processes. Two of the most essential chemicals in cool roof coatings are TiO2 and Quartzene.
TiO2 represents an important color component of cool roof coatings, adding a white pigment with light reflecting properties.[13] TiO2 functions by scattering visible light, leading to increased brightness and opacity, and resulting in a lighter coloring. When incorporated into a cool roof coating, TiO2 refracts solar rays away from the roof, reducing energy and sunlight absorption.
Quartzene is another important chemical used to create cool roof coatings. As a performance additive, Quartzene offers several important benefits, including increased solar reflectivity, and thus reduced solar ray absorption.
Quartzene reflects up to 95% of energy of the hottest infrared rays and is key to increasing a roof’s Solar Reflective Index (SRI).[14] The combination of Quartzene and TiO2 has proved to be especially effective at increasing solar reflectivity in cool roof coatings.
What are the Specific Benefits of Cool Roof Coatings?
Cool roof coatings offer many benefits to homeowners and represent one solution to reduced carbon pollution and energy expenditure on a global scale.
1. Lower Temperatures
Cool roof coatings decrease the temperature within an individual building, as well as contribute to overall lower temperatures within a city or area.[15] This helps keep both homes and cities cooler without relying on energy sucking systems. On hot days, reflective roof coatings have been proven to lower home temperatures by up to 30%.[16]
2. Increased Energy Efficiency
The energy efficiency of cool roof coatings impacts both local homeowners and the larger power grid. Homeowners can expect to use less electricity, and the electrical grid will experience less stress, resulting in overall decreased energy expenditure and fewer potential power outages. [17]
3. Increased Energy Savings
Homeowners can expect to cut down on air conditioning and energy costs, with cool roofs reducing air-conditioning demand by up to 27%.[18]
4. Less Maintenance
Roofs with cool coatings also tend to have a longer life than regular roofs; less exposure to high temperatures increases their durability, resulting in fewer maintenance costs.[19]
What Does a Cool Roof Cost?
The installation and product cost of a reflective roof can vary, yet applying a cool roof coating to an already existing roof tends to be much cheaper than installing a new roof.[20]
The Oak Ridge National Laboratory offers a calculator to estimate your savings. This tool takes into account location as well as electricity, heat, and air conditioning costs.[21]
Cool roofs with a greater capacity for solar reflectance and cool roofs in warmer climates will likely reap more savings, yet all cool roofs will ultimately reduce energy costs.
Cities and other programs may offer rebates and financial incentives for those looking to install a cool roof, with cool roof rebate programs existing in 11 states. Read more on the Cool Roof Rating Council’s financial incentive programs to determine if you qualify.
With the benefits of cool roof coatings abundant for both homeowners and the environment, cool roof coatings offer the perfect, low-maintenance solution to decrease energy expenditure and costs.
We understand that finding the right cool roof coating can be difficult and overwhelming, yet our team at Van Horn Metz is here to help create the best chemical solution for your specific needs. Reach out to one of our sales representatives to discuss specialty chemical products that we can provide for your cool roof coating.
[1] https://cielowigle.com/blog/passive-cooling/
[2] https://www.energy.gov/energysaver/cool-roofs
[3] https://www.paint.org/about/industry/sustainability/cool-roofs/
[4]https://www.epa.gov/green-infrastructure/reduce-urban-heat-island-effect#:~:text=%22Urban%20heat%20islands%22%20occur%20when,heat%2Drelated%20illness%20and%20mortality.
[5] https://www.attainablehome.com/cost-of-cool-roofs-are-they-worth-it/
[6] https://www.washingtonpost.com/climate-environment/2023/06/20/cool-roof-coatings-global-warming/
[7] https://www.washingtonpost.com/climate-environment/2023/06/20/cool-roof-coatings-global-warming/
[8] https://www.paint.org/about/industry/sustainability/cool-roofs/
[9] https://www.energy.gov/energysaver/cool-roofs
[10] https://coolroofs.org/
[11] https://www.paint.org/about/industry/sustainability/cool-roofs/
[12]https://hproofingpro.com/cool-roof-coating-vs-covering-an-in-depth-comparison/#:~:text=Examples%20of%20cool%20roof%20coatings,%2C%20and%20single%2Dply%20membranes.
[13] https://www.tipure.com/en
[14] https://aerogel.se/
[15] https://www.paint.org/about/industry/sustainability/cool-roofs/
[16] https://www.paint.org/about/industry/sustainability/cool-roofs/
[17] https://www.energy.gov/energysaver/cool-roofs
[18]https://www.epa.gov/heatislands/using-cool-roofs-reduce-heat-islands#:~:text=A%20California%20study%20found%20that,50%20cents%20per%20square%20foot.
[19]https://hproofingpro.com/cool-roof-coating-vs-covering-an-in-depth-comparison/#:~:text=Examples%20of%20cool%20roof%20coatings,%2C%20and%20single%2Dply%20membranes.
[20] https://www.angi.com/articles/beat-heat-energy-efficient-cool-roof.htm
[21] https://web.ornl.gov/sci/buildings/tools/cool-roof/
White roofs make a lot of sense in many applications, but sometimes you need to select some other color as part of the roofing decisions. By choosing colored pigments with IR reflective properties you can still obtain cool roof performance. Start with your black pigment to get the best results: VHM represents OXERRA Americas.