What Are Cool Pigments and How They Cool A Providence Roof?

It’s widely known that lighter-colored roofs absorb less sunlight and heat than darker ones. This has a significant impact on your choice of roof color in Providence, influencing temperature control, cost savings, and energy efficiency. Your decision should take into account your region’s climate and your specific efficiency goals, which may result in some color limitations for homeowners in Rhode Island.

However, advancements in metal roof painting and color dynamics allow modern roofs to be coated with cool pigments. These painting innovations create the same energy efficiency benefits that regular roof color paintings achieve. The key difference is that these benefits apply to every type of color, no matter how dark or light it is.

Do you think cool pigments are the right choice for your Providence metal roof? Learn more about what color pigments are, how do they benefit the household, and the pros and cons of using them.

A collage of some of the different metal roof styles and color options available from Erie Home.

What are Cool Pigments?

Cool pigments, also known as cool roof coatings, are applied to any metal roof of any color, whether it is dark or light. These pigments have properties that reflect infrared (IR) energy from the sun, which manages to keep the roof cool. This process allows the building to take in less heat, and as a result, maintains a lower temperature indoors. Cool roofs essentially keep the building more energy-efficient, since there is less necessity to turn on the air conditioner and consume energy, which also reduces energy bills. These coatings also resist ultraviolet (UV) rays, which increases the lifespan of the roofs.

Cool pigments come in two varieties.

• Cementitious. These coatings are composed of ceramic and concrete particles, both dissolved in white acrylic paint. These coatings have no humidity protection, so waterproof protection must be applied first.

• Elastomer. These pigments contain extra polymers that make them less brittle. They are also more water-resistant. This benefit is important, since most cool roofs attract extra humidity, which comes with drawbacks such as the formation of algae.

Pros of Cool Pigments

Using cool pigments in your metal roof brings plenty of advantages associated with light color roofs. In fact, cool pigments bring the most benefits to dark color roofs, since their lighter counterparts already have enough reflective properties.

• Greater Range of Color Choice. As mentioned, cool pigments are applicable to any type of color choice. Before, the IR reflection benefits of a cool roof were only reserved for roofs with light colors. Now, home and building owners can enjoy the same energy efficient capabilities with their choice of roof color if they apply cool pigments.

• Reduction of Heat Island Effect. In general, larger cities are hotter than suburbs and small towns because the rooftops and roadways usually absorb the heat of daylight and release it at night. This phenomenon is known as the Heat Island Effect. Roofs treated with cool pigments can reduce this effect by reflecting energy instead of absorbing it and releasing it at night, thus creating less heat in the surrounding area. This process can also reduce the energy consumption of nearby buildings.

• Decrease of Greenhouse Gases. Beyond the cool roofs’ reduction of air conditioning and energy consumption, they also reduce greenhouse emissions in another method. The energy reflected by cool pigments escapes the planet’s atmosphere, thus not contributing to overall global warming. Absorbed solar energy, on the other hand, becomes heat that escapes the atmosphere and is a part of global warming.

• Effective Results in Low Pitch or Sloped Roofs. Cool pigments are much more beneficial in buildings that have roofs with slopes or low pitches. The angles of these roofs receive sunlight more directly. Therefore, using cool roof coatings in these buildings can significantly rectify that design feature.

Cons of Cool Pigments

While cool pigments, and cooler roofs in general, bring benefits to many homes, they are not always appropriate for every building. In addition, there are a few drawbacks that must be considered before deciding to apply these coatings.

• Lack Effectiveness in Colder Climates. The effects of cool pigments are available throughout the entire year. Unfortunately, that means roofs will not absorb heat during the winter season or in areas with colder climate, even if they have a darker color. That heat gain is necessary to reduce the use of heaters, as well as energy consumption and bills. Home owners who fit this description can use alternatives such as proper attic insulation to keep the heat out of their houses without losing the ability to absorb it when necessary.

• Reduced Efficiency in Steep Roofs. Just as with roofs located in colder climates and during the winter, cool roof coatings are not as effective in steeply pitched surfaces. They do not have problems with absorbing extra heat, so the benefits are nowhere as strong.

• Greater Humidity. Because treated roofs reflect IR energy away to keep the area as cool as possible, it means there is less heat to evaporate nearby humidity. Therefore, these roofs attract greater moisture. This is concerning in regions with greater humidity, as the excessive moisture that cool roofs allow also create the conditions for algae and mold to exist. These organisms can compromise the integrity of the roof over time and decrease its durability.

• Absorption of Heat by Non-Cool Surfaces. Even though metal roofs coated in these pigments maintain the nearby area cooler, which decreases the Heat Island Effect, there is a possibility that darker or non-cool roofs or areas will absorb the heat reflected by the cooler surfaces, rather than escaping the atmosphere safely. A greater use of cool pigments can reduce this potential issue.

To Cool or Not to Cool

Cool pigments can guarantee the same energy efficient benefits that light color roofs have to any other surface, even darker colors. They allow owners a greater ability to choose the right color for their building while also saving on energy bills and contributing to the wellbeing of the environment.

Unfortunately, not every Rhode Island home or building roof is suited for these cooling measures. Consider both the benefits and the drawbacks of these coatings in your home, and more importantly, in the area you live in. Make sure any painting project you have is compliant to state, city, and neighborhood restrictions and guidelines.

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