“Roofing materials that can deliver high solar reflectance and high thermal emittance are considered cool roofs. These roofs reflect and emit the sun’s heat instead of absorbing it, keeping buildings cooler and reducing the amount of energy needed to cool them. Coolness is measured by two properties: solar reflectance and thermal emittance. Both properties are measured from 0 to 1; the higher the value, the cooler the roof. Reflective roofing technologies are increasingly included in federal, state and local energy codes. Many opportunities exist in both new construction and re-roofing to install cool roofs and other energy-improvement options.”
Cool roofs are highly reflective and emissive materials that stay 50 to 60o F cooler in the summer sun, thereby reducing energy costs, improving occupant comfort, cutting maintenance costs, increasing the life cycle of the roof, and contributing to the reduction of urban heat islands and associated smog.
What are the Benefits of a Cool Roof?
A cool roof can significantly reduce your cooling energy costs and increase your comfort level by reducing temperature fluctuations inside your home. Average energy savings range from 7%-15% of total cooling costs.
When it comes to making homes more environmentally friendly or sustainable, cool roofing often doesn’t receive the immediate attention it deserves. Nevertheless, it’s worth noting that specific green building programs, like LEED from the Indian Green Building Council, actually recognize and provide credit for the installation of a cool roof. So, if your aim is to save energy and create a more eco-friendly home, opting for a cool roof is a viable and effective strategy to accomplish that objective.
Selection of Cool Roof Coating
In regions with extended cooling seasons and frequent hot days, dark-colored shingles on your roof may contribute to increased heat within your home. This heat gain can result in higher cooling costs, especially during peak demand periods, such as late afternoons when electricity providers face potential issues like blackouts. Fortunately, studies conducted in high-temperature areas have revealed that homeowners can significantly reduce their electricity consumption, particularly during peak load times, by 10 to 30%, simply by applying a heat-reflective coating to their roof surfaces. These coatings, commonly referred to as cool roof coatings, are liquid “paints” that can be applied to existing roofs.
Cool roof paint comes in two different forms. Cementitious coatings are made up of concrete and ceramic particles dissolved in white acrylic paint. Elastomer coatings contain additional polymers to keep the coatings less brittle and more water-resistant. In fact, since cool roofs can draw humidity-in turn promoting the growth of algae and mold-it’s standard practice not to apply cementitious coatings on surfaces that haven’t been first prepped with a waterproof solution.
Cool roof coatings offer a double win for homeowners. By improving the solar reflectance of your roof surfaces, these coatings effectively reduce the amount of heat absorbed, leading to lower electric bills. Additionally, many cool roof coatings are formulated with UV-resistant materials, which not only contribute to energy savings but also have the potential to extend the lifespan of your roof. So, with cool roof coatings, you can enjoy both immediate financial benefits and long-term roof durability.
Is Your Roof Right for Cool Roof Coatings?
While cool roof coatings offer benefits, it’s important to consider that not every roof is suitable for their application. For example, if you reside in an area with shorter summers and colder winters, using cool roof coatings may have unintended consequences, potentially leading to increased energy bills. This is because the reflective surfaces of cool roofs can offset heat even during winter when solar heat gain can provide some relief by reducing heating costs. It’s crucial to assess the specific climate conditions and heating requirements of your region before deciding whether cool roof coatings are a suitable choice for your roof.
When considering cool roofs, it’s essential to take into account the average humidity levels in your location. While cool roofs offer benefits, they have the potential to draw in excess moisture due to reduced heat that would normally aid in evaporation. In areas with high humidity, this can create conditions conducive to the growth of algae and mold. These issues not only degrade the roof over time but also reduce its durability. Therefore, homeowners in regions with high humidity should carefully evaluate the potential risks of moisture-related problems before opting for a cool roof. Proper maintenance and proactive measures to prevent algae and mold growth may be necessary in such environments.
It’s important to note that cool roof coatings tend to perform best on roofs with a low pitch or slope. Such roofs have a higher tendency to absorb significant solar radiation due to their angled orientation, directly receiving the sun’s rays. In contrast, roofs with very steep pitches may not experience the same issues with excess heat accumulation, and therefore, they may not benefit as significantly from cool roof coatings. The impact of cool roof coatings on steeply pitched roofs is likely to be less pronounced due to their inherent design that facilitates better heat dissipation. Thus, the suitability and potential benefits of cool roof coatings may vary depending on the pitch or slope of the roof.
Long Term Advantages
A cool roof is a concept that helps to reduce the heat absorbed by a building from sunlight. Heat and light from the sun is received in various wavelengths. If the heat is reflected properly, then the building will not absorb the heat and cause discomfort to the occupants. When installed correctly, cool roofs can reduce the urban island heat effect, provide water proofing and enhance roof durability.
The main advantages of having cool roofs (reflective roofs) are
1) Reduced utility bills
Since heat from the sun is reflected, the heat absorbed by the building is less. This means that the need for air conditioning is less. Thus, there is tangible savings in utility bills.
2) Reduced urban island heat effect
The urban island heat effect refers to the concept where there is a lack of moisture in an area due to lack of vegetation and heavy urbanization. Temperatures can go up by as much as 50 to 90 degrees Fahrenheit more than the actual air. This is reduced by having a reflective roof.
3) Enhanced roof life
It is a known fact that continuous exposure to heat will cause deterioration of materials. Roofs are no exception. By having a reflective roof, heat absorption is reduced and roof life is considerably enhanced.
4) Positive environmental impact
Reduced utility bills and reduced island heat effect will mean that the overall carbon footprint is reduced.
5) Waterproofing
Cool roofs when correctly installed offer excellent waterproofing and this is an added advantage.
Market Potential
The global cool roof coatings demand can be attributed to energy savings offered by this product, coupled with adoption of green building codes by most governments. Concerns regarding increasing carbon emissions and energy consumption have pushed government authorities to implement green building codes to regulate energy efficiency. Such regulations propose various practices that contribute to reduction of energy consumption in commercial and residential buildings. Cool coat technologies are being recognized as an efficient way of lowering energy consumption in regions with hot climatic conditions.
The Cool Roof Rating Council (CRRC) develops credible and accurate methods for evaluating thermal emittance and solar reflectance of these products. It highly contributes to dissemination of such methodologies and information to interested parties. It also standardizes and regulates various roofing products, including coatings.
A prominent trend observed in the market is shifting consumer preference for cost-effective and long-lasting coatings as opposed to short-term, quick-fix solutions. Property managers and industrialists have begun studying the life-cycle assessment of cool roof coatings. Although cheaper variants help in saving a few dollars, the inevitable need to re-coat after three to five years turns out to be exponentially costlier in terms of material, labor, and time.
Cool roof coatings have gained popularity among consumers as they have been witnessing significant reduction in cost of air conditioning. Rising inclination of consumers toward energy savings, backed by monetary support from the government in the form of rebates and discounts, is expected to significantly benefit the market. However, high cost of these techniques is projected to remain a challenge in the market. Product quality is mostly reliant on raw material, which is likely to impact the pricing of the final product.
The global cool roof coating market size is expected to reach USD 5.41 billion by 2025, according to a new report by Grand View Research, Inc., registering a 7.0% CAGR over the forecast period. Energy savings offered by these coatings, along with favorable regulations, are slated to drive the market.
Use of cool roof coatings can prevent structural deformity caused by severe temperature fluctuations. It also lowers dependency of air conditioning by reducing heat built up in buildings, which in turn, reduces energy consumption.
Favorable regulations and government support in the form of tax benefits and financial incentives are expected to propel product demand. Increasing awareness regarding energy savings as well as environmental benefits offered by cool enamels will play a vital role in market expansion. Manufacturers are focused on development of new technologies to enhance UV resistance of these coatings. Introduction of microcells and nanotechnology for reducing heat flux and increasing energy conservation is projected to drive demand for cool roof coatings over the forecast period.
In summary, cool roofs play a crucial role in reducing heat absorption from sunlight, promoting occupant comfort. They can effectively address the urban heat island effect, provide waterproofing, and improve the longevity of roofs when installed correctly.