Reefer trailers may depend on a refrigerant to get cold, but it’s the thermal efficiency provided by the trailer’s insulation that ultimately ensures the thermal integrity and sustainable transportation of temperature-sensitive cargo. Enhancing a reefer’s thermal efficiency can provide many benefits, such as keeping cargo fresh longer, reducing operational costs, and minimizing environmental impact.
When a trailer is insulated correctly, the reefer’s cooling unit doesn’t have to work as hard. Advancements in this critical component are necessary as the transportation industry looks toward a more sustainable future.
MAXIMIZING THERMAL EFFICIENCY AND COMBATING WATER WEIGHT GAIN
Colby White, Great Dane’s Electrification Product Manager, says that traditional foam insulation isn’t always up to the task when it comes to getting the most out of the life of a trailer.
For example, he says the weight of some reefer trailers can increase up to 500 pounds over five to ten years as moisture intrudes traditional foam insulation through its permeable liner. More weight means less efficiency and a limited load size over time.
“Traditional foam is known to degrade about 5% each year due to outgassing, where material will release gasses into the air when exposed to environmental effects such as heat or a vacuum. As a result, in most instances, a trailer could become 25% less efficient in retaining its cold air in just five years,” White said.
Great Dane has patented a durable and lightweight composite liner called ThermoGuard to combat these issues. It’s significantly stronger than traditional liners, and because it’s virtually impermeable, moisture intrusion is significantly reduced, and thermal integrity is greatly improved.
“Weight is a big consideration, so using something like Great Dane’s ThermoGuard product allows for a longer use of the trailer through less degradation of the foam along with less weight through moisture absorption,” White says. “With ThermoGuard, degradation is significantly minimized, and the effect is that the trailer requires less energy to keep the unit cool.”
Thermal Efficiency and Trailer Electrification
As the industry marches forward to develop the electric trailers of tomorrow, efficiency becomes more important than ever. In the realm of electrification, a more efficient trailer equals more range, which ultimately ties into uptime and reduces operational costs.
Great Dane studies show that a refrigerated trailer with ThermoGuard, operating at -20F in a long-haul capacity, can save up to 2,100 gallons of fuel over seven years. The energy contained in one gallon of diesel is equivalent to about 37.1 kWh of electricity. Results vary depending on application and maintenance practices, but reefer trailer owners can experience an average savings of 200 gallons of fuel per year, or the equivalent of 7,420 kWh of electricity.
The evolution of trailer insulation is a pivotal step in shaping the future of temperature-sensitive cargo transportation. As the industry begins to adopt eTRUs, ThermoGuard excels in terms of higher levels of efficiency, durability, and impermeability to moisture.
Great Dane’s New HFO Insulation Technology
Over the lifespan of a trailer, conventional insulation materials often deteriorate, releasing their blowing agents into the atmosphere. When these agents are considered greenhouse gases, they contribute to amplifying infrared light, potentially exacerbating global warming.
Great Dane has taken a significant step in enhancing refrigerated trailer insulation technology, moving away from conventional methods and embracing Hydrofluoroolefin (HFO) technology. Unlike traditional insulation, HFO-based insulation significantly reduces the impact on global warming. The HFO-based liquid blowing agent used in this new technology minimizes the release of chemicals that amplify infrared light, aligning with efforts to combat global warming.
This innovative HFO technology ensures top-notch thermal integrity for fleets and meets the Environmental Protection Agency’s (EPA) requirements by eliminating the use of hydrofluorocarbons (HFCs). Moreover, this advancement is anticipated to extend the trailer’s overall lifespan compared to conventional foam insulation, marking a significant stride toward sustainability and longevity in refrigerated trailer design.
