We all know that the Earth is going through a period of climate change, and it’s more important than ever to do our part to reduce our impact on the environment. One way we can do this is by installing cool roofs.
But what are cool roofs? Cool roofs are roofs that have been designed to reflect sunlight and heat, which helps keep buildings cooler in warm weather climates. Let’s go into the details of cool roofing, what they cost, and how they help combat climate change.
What Are Cool Roofs?
Cool roofs have been around for centuries. Ancient Greeks were known for painting the roofs of their homes white. However, the more modern version of cool roofs became popular in the Western world in the early 2000s as a way to combat climate change. There are several types of cool roofs:
- Reflective Roofs: Reflective roofs are made of materials that reflect sunlight and heat into space. This is known as high solar reflectance. This type of roof is best for hot climates, as it can help keep buildings cooler in the summer.
- Emissive Roofs: Emissive roofs are made of materials that emit infrared radiation. This is known as high thermal emittance. This type of roof is best for cold climates, as it can help keep buildings warmer in the winter.
- Naturally Cool Roofs: These roofs use white vinyl and other white surface materials. This helps a building increase its ability to reflect light (also known as a building’s albedo).
- Coated Roofs: Buildings topped with traditional roofs can be retrofitted with a solar reflective coating to increase the amount of sunlight reflected.
- Insulated Cool Roofs: This roofing system pairs thermally resistant insulation with a white or reflective coating, thus creating an effective thermal barrier.
- Green Roofs: These roofs, also known as vegetated cool roofs, are covered with plant life. However, due to added weight, they must be designed or carefully retrofitted to accommodate the change. Green roofs don’t reflect as much sunlight as white and cool roof materials, but they offer other environmental and aesthetic benefits.
What Cool Roofs Cost
The cost of a cool roof depends on the type of roof you install. Reflective roofs are typically more expensive than emissive roofs, but they can save you money in the long run by reducing your energy consumption.
A typical roof replacement can cost anywhere from $6,000 to $20,000, but a cool roof can cost thousands more. This is only if you need to purchase specialized technology, depending on your climate and roof pitch.
However, the increased cost of a cool roof can be offset by the money you save on energy bills. Cost is only a concern if you are looking to convert a standard roof that’s in good condition. If your roof needs to be replaced anyway, the cost difference may be negligible.
The Cool Roof Rating System
To rate the coolness of a roof, the Cool Roof Rating Council (CRRC), an independent nonprofit organization, developed a rating system. The CRRC rates roofs by calculating the solar reflectance index (SRI) of the roofing products.
The CRRC bases SRI calculations on two factors: solar reflectance and thermal emittance. Solar reflectance is the amount of sunlight that a roof reflects. Thermal emittance is the amount of heat that a roof emits. It also considers wetting delay, the amount of time it takes for water to penetrate a roof.
The CRRS rates roofs on a scale from 0 to 100, with 100 being the coolest. A roof with a rating of 100 would reflect the most sunlight and heat into space, while a roof with a rating of 0 would absorb the most sunlight and heat.
How Do Cool Roofs Help Combat Climate Change?
Cool roofs help combat climate change in three ways:
- By reducing energy consumption in buildings: Cool roofs can help reduce the amount of energy consumed by air conditioning by up to 15 percent. This is because they keep buildings cooler, which means that air conditioning units don’t have to work as hard to cool them down.
- By reducing greenhouse gas emissions: Cool roofs help reduce greenhouse gas emissions by reducing the amount of energy needed to cool buildings, which means fewer greenhouse gases are emitted into the atmosphere.
- By lowering temperatures: Higher temperatures cause several health and environmental issues, from changing weather patterns to increasing the formation of smog in the air. But citywide programs to install cool roofs can help lower the average city surface temperature, which can actually cool the air.
Takeaways on Cool Roofs
Overall, cool roofs are a great way to combat climate change and reduce your energy consumption. They’re available in both reflective and emissive varieties, so they’re perfect for any climate.
The cost of a cool roof can be offset by the money you save on energy bills, so they’re a great investment for any home or business. If you’re interested in installing a cool roof, talk to your local roofing contractor to see what options are available to you.
Bill Starkey 