Frost Fight: Challenging Winter Utility Installations Have A Calgary Contractor Seeing Infra-Red

January 2012, Vol. 67 No. 1

New technology
When it was determined that the service contractor simply didn’t have the tools or the time to complete the task, ATCO started considering other options. That’s when ATCO heard its seasoned mains-installation contractor, Dunwald & Fleming Enterprises Ltd., had recently purchased some infrared heating devices. The new technology boasted to thaw ground faster than any other method, so ATCO quickly asked Dunwald & Fleming to step in and put the heaters to the test.

The new infrared heaters were Serious Toasters from Serious Thermal Products. Each Toaster measures only 10 feet long by two-feet wide, but multiple units can be placed together in a series along the route of the proposed trench. They are powered by propane and run from a 110-volt power source. Using targeted reflectors, the infrared technology of the Toasters efficiently directs heat into the ground with minimal heat loss. Thanks to these advantages, the units appeared to be an ideal solution for the Skyview Ranch job.

“We explored several options before finally finding the infrared heaters,” said Marv Dunwald, owner of Dunwald & Fleming who struggled to identify alternatives to coal and straw. First, he tried glycol boiler systems to heat the ground, but they proved to be extremely inefficient for utility work. “There was so much heat loss that it would take three to four days just to thaw one foot of ground,” he said.

Next, Dunwald experimented with trailer-mounted units, which he found to be cumbersome. “A trailer only thaws about 12 feet at a time,” he said. “Plus, there are only about 10 units in all of Calgary, so nobody can get their hands on one.”

Upon discovering the Toasters, Dunwald purchased 10 units. Therefore, his plan for the Skyview Ranch job was to line all 10 of them up to thaw 100 feet of ground at a time. After one stretch of ground had thawed, he would move the Toasters ahead to start heating more frozen ground while his crew trenched the first 100 feet. The process would be repeated until 1,000 feet of ground had been thawed and trenched with gas lines installed and the dirt backfilled.

The infrared units provided a safe, quiet heat source, allowing Dunwald to place the Toasters against buildings and fences, and let them operate overnight without close supervision. “Glycol boilers would have been too noisy to operate overnight near residential areas,” said Dunwald, “and most other systems use open flames, which would have been a fire hazard on our jobsite.”