Fleet managers have come to learn that continually improving a fleet’s environmental profile can also strengthen operational and financial performance, thanks to bottom-line benefits that come with adoption of sustainable technologies. Nowhere is this more evident than in refrigerated operations, where the latest green technologies can bring cool financial rewards.
Here are a few summarized examples.
1. Use Tier 4-Compliant Units
Upgrading to newer refrigeration units designed to comply with the U.S. EPA’s Tier 4 emissions standard can result in significant fuel-saving benefits. When transport refrigeration unit (TRU) manufacturers developed refrigeration units to comply with the Tier 4 standard, they added innovations to reduce fuel consumption.
For example, Carrier Transicold’s Tier 4-compliant X4 series TRUs deliver greater refrigeration capacity while using less engine power – a 35 to 50 percent higher BTU per gallon efficiency boost at typical rating conditions versus prior Carrier models. The new ultra-high-efficiency designs reduce fuel consumption up to 22 percent while also using less refrigerant, which is another benefit for the environment.
Fuel savings also help the atmosphere by reducing greenhouse gas emissions. That means by converting to efficient TRUs such as Carrier Transicold’s Tier 4-compliant Vector unit, which is capable of reducing fuel consumption by up to 26 percent compared to prior models, a fleet also can potentially reduce TRU greenhouse gas emissions by up to 26 percent.
2. Consider Electric Standby
The ability to plug some TRUs into electric standby power when parked allows the refrigeration system to run with the diesel engine off. This conserves fuel for the highway while eliminating the costs, noise and emissions associated with running the diesel engine.
The capability offers dual benefits of environmental and economic savings, because typically it is 40 to 75 percent less expensive to operate the unit on electricity, rather than diesel power.
Even with the recent drop in the price of fuel, use of electric standby still makes economic sense, and the noise and emissions reductions help fleets to be good neighbors within the urban and suburban communities where they operate.
3. Optimize the TRU’s Fuel Efficiency
Far from just simply setting temperatures, modern TRUs are equipped with sophisticated control systems that are, essentially, onboard computers with a suite of software tools for managing refrigeration unit performance. Software enables preset configurations that provide optimum temperature control for commodities hauled, and fleets also can configure settings for optimized fuel efficiency.
Depending on the cargo being hauled, TRUs can be set to run continuously or in a more energy-conserving start/stop mode. Tight temperature control may be required for some commodities, whereas others might allow more variation.
With sensors that measure temperatures both outside and inside the trailer, ambient-based control logic helps some TRU controllers make intelligent decisions about cooling and energy management, helping determine when the unit needs to run and how hard it needs to work.
Once fleets and their customers agree on temperature control parameters for the goods being hauled, TRU variables can be set for maximum efficiency and proper product protection with measurable benefits.
One large over-the-road customer achieved 36 percent reduced run-time, translating into 2 million gallons of diesel fuel saved each year. This also reduced fleet carbon emissions and extended engine service intervals for further savings.
4. Try Door Switch Sensors
When it comes to environmental performance, there’s an “open and shut case” for using door switch sensors. These enable TRUs to automatically shut down the refrigeration system when trailer doors are opened for unloading, preventing the refrigeration system from attempting to cool an infinite space.
Running the TRU with open doors pulls in warm, humid air that can ice the evaporator coil, reducing performance while wasting fuel and contributing to emissions in the process. Carrier Transicold’s Door Man control software is an example of a tool that monitors outside ambient conditions to manage whether and how the refrigeration system runs when doors are opened.
If shippers require the TRU to be running while loading, the door switches can be configured to run the unit in low speed when the door is open, offering significant fuel savings and still satisfying shipper requirements.
5. Harness the Sun
One of the latest innovations for TRUs is the application of solar panels that harness daylight to maintain peak performance of refrigeration unit batteries in an environmentally sustainable way.
Solar panels can be mounted to the top of a trailer just behind the TRU, providing an alternate source for charging TRU batteries, which are increasingly tapped to power additional electronics, such as telematics devices, fuel-level sensors, interior trailer lighting and other accessories.
Solar panels can help conserve fuel and reduce emissions by minimizing the need to run the TRU engine to charge the battery. The panels also can help prevent service calls to start a unit with a dead battery.
6. Rest Easy with Shore Power
Located at many rest areas along major interstate corridors, truck stop electrification (TSE) has provided another way for drivers to shut off truck engines and plug into electric power when parked for breaks.
Traditionally, TSE delivers electricity to power appliances, heaters and air conditioning in the sleeper cab. Some TSE areas now offer higher voltage connections for TRUs with electric standby capability.
Although a nominal fee is charged for the electricity, drivers save fuel for the highway and eliminate engine emissions. Reducing engine noise can contribute to better rest for drivers, too, and they’ll sleep better knowing they’re reducing environment impacts.
David Kiefer is director of product Management for Carrier Transicold North America Truck/Trailer/Rail (www.trucktrailer.carrier.com). The company provides global support of the cold chain with a complete line of refrigeration systems for trucks, trailers, marine containers and intermodal operations.
