The blistering dog days of summer burn off into crisp, cool nights. A chill creeps down your spine when you leave for work without a jacket. The air smolders with the smell of burning leaves and the trees reflect a kaleidoscope of color as your productive rigs roll down the road. You know what’s coming. Take a deep breath, gather your wits and get ready to go to battle against cold-weather starts and corrosion. Winter is right around the corner and Fleet Equipment has you covered. Heed these equipment-focused tips to stay frosty and keep your trucks running through the worst old Jack Frost can throw at you.
Idling definitely keeps the truck warm to avoid freezing up in frigid temperatures. It’s also a great way to waste a lot of diesel. Auxiliary power units (APUs)—both diesel and electrically powered—offer a solution to keep your cabs warm, comfortable and powering addition creature comfort devices. When it comes to taking care of the engine, coolant heaters ensure that the engine is ready to roll regardless of how cold it gets at night.
Coolant heaters are typically started by a control switch that kick on the heater, which does a safety check of components such as flame sensor, water temperature sensor, coolant pump, fuel pump, etc. The coolant pump starts up as the heating element heats up and the fuel pump starts to draw diesel into the combustion chamber. A fuel and air mixture is ignited to heat the coolant. The temperature monitors the temperature to ensure that the recommended temperatures are maintained and your engine starts without a hitch.
Given that the coolant heater is still using diesel fuel to create its heat, how much fuel does it save versus engine idling? We put that question to John Dennehy, vice president of marketing and communications for Eberspaecher.
“It’s tablespoons compared to gallons,” he said. “The fuel used by a diesel fired heater is significantly less that a diesel engine running in the same period at idle. In terms of productivity, using the heater will allow the driver to start work earlier instead of waiting around until the truck is at operating temperature. If the driver runs the truck at the dock when unloading or loading or when waiting in queue, he or she will be able to use the heater as well; reducing idling and fuel costs.”
According to Josh Lupu, director of marketing for Webasto, idling can use up to 1 gal. of diesel fuel per hour. “By using a coolant heater, idling is not necessary because the coolant is circulated through the heater, warming the coolant and warming the engine—using a small fraction of what it would take to idle the engine,” he said. “This fuel savings adds up quickly and can mean thousands of dollars a year.”
Savvy fleet managers might be concerned about placing additional electrical burden on their trucks, given the ever-increasing number components that are drawing power from the battery. Both Eberspaecher and Webasto explained that very little battery power is needed and that coolant heaters typically have a low voltage shutdown that prevents the heater from drawing power that the truck needs to start.
As Eberspaecher’s Dennehy alluded to, you can also use the heat from the coolant heater to warm the cab. “We find a coolant heater can do everything that a customer needs, including supplemental heat to the bunk via OE heat exchanger,” he said. “Air heaters only heat the cabin, and if you are not concerned about coolant temperature it is a simple solution. If you need the coolant and cabin temperature, you need to use a coolant heater.”
Of course, it depends on application. In temperate climates where engine performance isn’t a concern, but taking the chill out of the morning air in the cab is, an air heater is a viable solution.
However, there is a growing case that is being made by both Eberspaecher and Webasto that a coolant heater will help keep the engine operating at the optimal temperature and improve engine performance.
“A coolant heater will heat the engine to operating temperature; Therefore, the emissions systems on the vehicle can work sooner than they do today,” Dennehy said. “Even in the warmer months, bringing the engine up to operating temperature is required for the emissions systems and the heater can do that. They can also help prolong your DPF filter changes by avoiding the cold starts.”
Webasto’s Lupu explained that a coolant heater increases exhaust temperatures rapidly, which aids in catalyst activity. “The important point is that while a coolant heater is thought of as a cold-weather product, it actually has emission benefits year-round,” he said. “It can significantly increase DPF performance which means a reduction in face plugging, wet stacking and filter overloading. Using a Webasto coolant heater can reduce PM by up to 66% and NOx by up to 40% on start-up.”
Lupu also shared results from an independent study commissioned by Webasto, which showed that PM emissions from an engine equipped with a 5 kW (17,000 BTU) Webasto coolant heater were reduced by 66% by pre-heating the engine during cold weather conditions, and by 27% during normal ambient conditions.
NOx emissions were reduced by around 40% by pre-heating the engine in both warm and cold climates. CO2 was reduced by 29% during winter conditions and 62% during normal ambient conditions. This was tested in a normal ambient testing environment of 75° Fahrenheit. This means that coolant heaters are effectively reducing emissions and improving DPF performance year-round in any part of the country, Webasto stated.
Both Eberspaecher and Webasto agree that coolant heater ROI is realized within one year of purchase, and in some cases, even sooner. Of course, this depends on fuel price, idling habits and heater usage.