Reflective Coating Used for Rooftop Billboards
Beer brand Coors Light has recently created 12 new, energy-efficient rooftop billboards, dubbed “Chillboards,” that utilize reflective white acrylic roof coating systems.
Described by Coors Light as “Ads Nobody Can See, But Everyone Can Feel,” the rooftop billboards aim to highlight the benefits of roof coatings in keeping buildings cooler and reducing air conditioning-related energy use and costs.
About the Chillboards
According to reports, the Chillboards were created atop 12 apartment buildings in Miami with A-300 Finish, a reflective white topcoat from Mule-Hide Products Co. Inc.’s acrylic roof coating system.
The coating in noted to have an initial solar reflectance of .85, meaning that a newly coated roof reflects 85% of solar radiation. In addition, the A-300 Finish is noted to be durable, flexible in low-temperature environments and has a high resistance to the effects of ultraviolet light.
Mule-Hide adds that the coating is Cool Roof Rating Council-rated and ENERGY STAR-listed.
A+ marketing right there @CoorsLight! "Chillboards" can cut roof temperatures by up to 50 degrees. The buildings below also cool down considerably, so residents don't have to run their air conditioners on full blast.https://t.co/fhriAGQqRf— Linda Thurman (@lathurm) May 11, 2022
For the project, more than 36,000 square feet of black roof surface—the equivalent of 90 average-size billboards—was coated with the reflective acrylic paint. In keeping with Coors’ goal of highlighting the benefits of cool roof coatings, the Chillboards used a typeface called “coolest.”
The font was specifically developed to cover more than 95% of each roof’s surface, while still allowing for phrases like “Made to Chill,” “Ads Keep Temps Down,” “Chillboards Help Cut AC Costs,” “Chilling the Roof Up to 50 Degrees” and “It’s Like a Coors Light for Your Roof” to be read.
Coors Light worked with creative director Set Free Richardson and street artist Andaluz The Artist to produce the Chillboards.
“It was fun to have been part of this creative campaign to educate people about the benefits of cool roofs,” said Mule-Hide Products Marketing Manager Jenny Emann. “Particularly in warm climates, like Miami, covering dark roofs with reflective roof coatings can produce big returns in keeping building interiors cooler and building occupants more comfortable, reducing the need for air conditioning and helping mitigate the urban heat island effect.”
Intended for short-term display, the 12 apartment roofs have since been coated in full with A-300 Finish. In a test conducted on one of the Chillboards, the coating was noted to have lowered the surface temperature of the roof by as much as 50 degrees.
Cool Roof Coatings Elsewhere
Earlier this month, Israeli startup SolCold announced that it had recently begun testing a new type of coating designed to help keep buildings—among other structures and industries—cool in the presence of sunlight.
SolCold reports the coating was developed after researchers contemplated the idea of harnessing the sun's radiation in a reverse method—meaning, instead of radiation heating up buildings, it would actually help to cool them down.
Made up of four layers, the coating includes: a reflective IR emission layer at its base; a flexible, transparent, and thermal conductive layer; a layer of active cooling particles; and a confidential top layer. The company adds that the cool roof coating also utilizes an anti-strokes fluorescent patent technology.
The resulting combination reportedly creates an active cooling effect with zero implementation and maintenance.
According to reports, the coating works by reflecting most sunlight, but allows some particles of light to breakthrough. The second layer of material then reacts to the specific radiation let in and emits particles of light at a higher frequency, thus causing the material to lose energy and get cooler.
The company recently applied the coating to car roofs for concept testing. In its study, SolCold found that a white car covered with the coating was as much as 25 degrees Fahrenheit cooler than a non-coated white car sitting in the sun in the middle of the day. A black car was reported to be 34 F cooler.
In upcoming tests, Konnect, Volkswagen Group’s innovation hub in Tel-Aviv, plans to apply the coating on one of its electric concept cars which it believes might help the vehicles travel further on a single battery charge thanks to a reduction of energy used for air conditioning.
While the largest future potential for the coating is on the roofs of homes and buildings, the startup has plans to first implement the coating with products from the automotive, telecom and defense, and even clothing industries.
Last year, engineers at Purdue University created what they called “the whitest paint yet”—a cool coating that aims to reduce buildings’ needs for air conditioning.
The team initially created an ultra-white paint in October 2020, and have been pushing to reformulate it for even “cooler” properties. The team recently published a paper about its findings in the journal ACS Applied Materials & Interfaces.
The researchers have gone so far as to say that this white is closest thing available to an equivalent of “Vantablack,” which absorbs up to 99.9% of visible light. On the flip side, the new whitest paint reflects up to 98.1% of sunlight, compared to 95.5% in the researchers’ previously developed ultra-white paint. Typically, white coatings expect to reflect 80-90% of sunlight.
There is one key element on achieving the whitest paint: barium sulfate.
To test the cooling traits of the paint, researchers used thermocouples to demonstrate outdoors that the paint can keep surfaces 19 F cooler than the ambient surroundings at night, and 8 F below their surroundings during high noon. Reportedly, the paint even works in winter climates.
Patent applications for this paint formulation have been filed through the Purdue Research Foundation Office of Technology Commercialization. This research was supported by the Cooling Technologies Research Center at Purdue University and the Air Force Office of Scientific Research through the Defense University Research Instrumentation Program. The research was performed at Purdue’s FLEX Lab and Ray W. Herrick Laboratories and the Birck Nanotechnology Center of Purdue’s Discovery Park.