Today’s engine heating systems available for the school bus segment help make vehicle start-up more efficient, reducing idle times and thus emissions and fuel consumption.

While all of the systems detailed here provide preheating for the engine and heat bus interiors in cold weather, not all of them use the same technology. The products from the three companies discussed below offer a variety of unique features and capabilities.

Espar’s E-Guardian system is compatible with biodiesel and features a digital programmable timer.

Espar Products Inc.
Espar Products, based in Mississauga, Ontario, offers its E-Guardian series of engine preheaters, which operate as hot water furnaces, utilizing the bus’ own diesel fuel and batteries to produce heat. The heater’s water pump circulates engine coolant to transfer heat to the engine and heat exchangers. “It’s a true, compact heating system with all components integrated into the system, not just a stripped-down heater,” says John Dennehy, Espar’s vice president of marketing and communications. “The heater is capable of heating the engine, defogging the windshield and heating the passenger compartment, all at the same time.”

The E-Guardian 5 provides engine preheating, instant defrost and driver standby heat. Basic kits for the E-Guardian 5 include the heater, installation kit and crash sensor.

The 8, 10 and 12 models — in addition to the features of the E-Guardian 5 — provide supplemental heat to the entire passenger cabin. Kits also include a protective enclosure, mounting tray and digital programmable timer.

“It is a mobile system, in that it goes where the bus goes — there’s no need for electrical plug-ins,” Dennehy says. “The E-Guardian also features a diagnostic system, making it easy to maintain. The brushless water pump motor and blower also provide reduced maintenance costs and downtime, even as units age,” he explains.

Timer controls can switch heaters on remotely one to two hours prior to engine start-up, eliminating cold starts and operator waiting time. The set-and-forget digital programmable timer allows for continual repetition of the selected cycle event. “The timer helps ensure heater usage, adding to the success of the [operation’s] idle reduction program,” Dennehy says.

The E-Guardian’s compact design allows for a variety of location mounts. Other features include automatic altitude adjustment and a boxed design for protection from the elements. “It’s packaged for turnkey installation, so there are no hidden costs for the school,” Dennehy says.

The 40,000 BTU-plus heating system is approved by the California Air Resources Board (CARB), Dennehy says. It is also verified by the EPA and compliant with Department of Transportation regulations. In addition, he says it is the only fuel-operated heater that is compatible with biodiesel.

Espar’s E-Guardian provides a particular benefit to school bus operations due to the availability of a nationwide service network through IC Bus dealers, Espar MSDs (master sales distributors) and other original equipment manufacturer dealers. “Driver acceptance of fuel-operated heaters has been exceptional, resulting in more successful idle-reduction technology implementation,” Dennehy says.

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Ventech’s Liquid Heat Generator system uses hydraulic friction to create heat.

Ventech LLC
Ventech’s rapid heating system, known as the Liquid Heat Generator (LHG), provides a heating capacity of 75,000 BTU to the compartment — 65,000 of which is created in the first five minutes, according to the company.

The elements that make up the system include the heat transfer chamber; the housing and working chamber of the LHG, where heat is generated through hydraulic friction; the manifold, which controls coolant flow and modulation; and the clutch, which is used to disengage the system based on system warmth or driving needs.

“The LHG 513 heats the engine’s coolant without a flame, fuel lines or exhaust,” says Reid Landis, director of sales and marketing. “Our device preconditions the interior of a bus and defrosts windshields, defogs windows and heats the interior.”

LHG serves as the primary heating source for the interior of the bus when the engine is cold or below optimum temperatures, reducing cabin and engine warm-up and idling time, and decreasing emissions by 50 to 70 percent, Landis says. “The heat our device generates goes directly into the heat exchangers on the bus, offering incredible heat even at idle,” Landis explains. “Producing 45,000 BTU of heat to the interior brings school districts and contractors in compliance with any state mandates on idle times and interior temperature minimums — the bus interior must be at least 45 degrees before the first student is picked up in Alaska.”

The heater has an estimated in-service life of up to 3,000 hours and a zero-maintenance feature that eliminates the need for weekly programming, according to the company.

Ventech has established a dealer network throughout North America and will soon be EPA certified, Landis says. The company’s placement on the Idle-Reduction Technology list will qualify its products for grants and funding opportunities. In addition, all LHG 513 manufacturing is done at Ventech’s plant in Wixom, Mich.

Webasto’s larger Scholastic heater model reduces fuel consumption and emissions; the smaller TSL 17 warms the vehicle without having to start the engine.

Webasto Product North America
The Webasto Scholastic and TSL 17 fuel-operated heaters preheat school bus engines to eliminate cold starts and extend engine life. The Scholastic heater reduces fuel consumption and tailpipe emissions, accelerates window defrosting, provides in-duty supplemental heat, stops white smoke at engine start-up, and is EPA verified, according to the company.

When Webasto began developing the Scholastic model, this type of heating system originating in Europe had not been engineered specifically for school buses, says National Sales Manager Paul Baczewski. “Because of some of the fuel regulations, they had to have external parts [to make them compatible],” he explains. “The Scholastic unit is the only product of its type that is fully built for a North American school bus.”

The Scholastic maximizes the heating capacity of the bus’ engine system. “That’s important when you’re transporting students with special needs, where you might have a handicap door that’s open for four or five minutes,” Baczewski says. “You have a massive heat loss. With the Scholastic unit, you’ll have virtually instantaneous heat recovery.”

Baczewski says the Scholastic heater is available through all the major school bus manufacturers and is entirely manufactured in the U.S., in Fenton, Mich.

The Webasto TSL 17 eliminates unnecessary engine idling, which results in reduced emissions by up to 90 percent, according to the company. The TSL 17 is CARB approved and EPA verified. Also known as the Thermo Top, the TSL 17 is a scaled-down version of the Scholastic that is used solely as an idle reduction product, warming the vehicle without having to start the engine, Baczewski says.

claire.atkinson@bobit.com