CASE STUDY: COOL COWS

Photo courtesy of Duro-Last, Inc.

Who would have thought that installing a cool roofing system on a barn would improve the milk production of cows? But that is exactly what happened in Chilliwack, British Columbia.

Who would have thought that installing a cool roofing system on a barn would improve the milk production of cows? But that is exactly what happened in Chilliwack, British Columbia.

In 1980, dairy farmer John Wynker built a 31,000-square-foot barn to house his herd of 160 to 170 dairy cows. Over the years, the existing metal roof began to have issues. It contained a sprinkler system used to cool the barn and keep the temperature down for the dairy cows. Although the sprinkler system did not work well, it still helped lower the excess heat created from the metal roof. However, this sprinkler system and the failed metal roof produced other problems—multiple leaks.

Wynker needed a new roof that was durable, leak-proof, and would keep his cows cool, safe, and dry. Wynker contacted John Grimard, owner of J.G. Roofing in Chilliwack, who suggested installing a cool roofing system.

According to Grimard, the white membrane would be the perfect fit for the barn because it is durable, leak-proof, and virtually maintenance free. Plus, Grimard explained that the roofing system could save on energy costs for the barn during the summer months.

In addition, the manufacturer offers prefabrication, which means the majority of the membrane seaming could be done in a controlled factory environment. Thus the potential for rooftop installation errors and leaks would be reduced considerably. The membrane could be produced in prefabricated sheets of up to 2,500 square feet, which would make the installation easier and less labor intensive. That is even more important in times of skilled labor shortages, which are seen today.

Grimard’s crew went to work. They re-roofed the barn without a tear-off, avoiding potential problems, such as accidentally dropping materials into the cows’ feed, which could have proven harmful to the animals. The crew also added insulation and ventilation, and removed the old leaky sprinkler system, leaving only the existing fans in place.

Another benefit of the cool roofing system for the barn was its flexibility. A large barn tends to expand and contract with wind and temperature changes, and the membrane system allows this movement without jeopardizing the performance of the roof.

Shortly after the installation, Wynker discovered other benefits that surprised both him and Grimard. Just one week into the project, the herd’s milk production increased to the point where the holding tank overflowed. Wynker determined that the increase was due to the cooler temperature in the barn. He found that in hot weather, his barn stayed cooler with the cool roofing system, which helped reduce the dairy cows’ stress level and resulted in their giving more milk.

Plus, the farmer noted how quiet the barn was when it was windy or raining. “The old metal roof was always very noisy during bad weather,” he says. During the winter months, the barn stayed warmer and prevented the cows’ watering troughs from freezing.

The best news for Wynker? He saved money and received a leak-proof roof!

“In the first six months, I saved about $22,000 in operational costs, and I attribute about 90 percent of that to the cool roofing system and the remainder to the added insulation,” says the dairy farmer. “That translates into saving around $44,000 a year, and my roof no longer leaks.”

CASE STUDY: SUMMERFIELD APARTMENTS, NORTHFIELD, MINNESOTA

Images courtesy of Duro-Last, Inc.

Images courtesy of Duro-Last, Inc.

When these two images were created, the outside temperature was 83 degrees Fahrenheit. The top green square in the infrared image shows the temperature of a white membrane cool roof: 89 degrees Fahrenheit. The middle red square shows the temperature of a BUR roof: 115 degrees Fahrenheit. And the red showing the temperature of the asphalt road and parking is 108 degrees Fahrenheit.

The impact of a cool roof is not apparent to the eye, but becomes clear with the help of infrared imagery.

The two images—a photo at the top, coupled with the thermal image of the same scene on the bottom—tell the story of how cool roofing in the form of white membrane keeps a building cool. These images record on urban scene in Northfield, Minnesota, on a fall morning at 11:26 a.m., following morning showers, when the outside temperature is 83 degrees Fahrenheit. The cool roof measures 89 degrees Fahrenheit, while the built-up roofing (BUR) has reached a blistering 115 degrees Fahrenheit. That’s 7 degrees Fahrenheit hotter than the 108-degree Fahrenheit temperature of a nearby asphalt parking lot.