Not just blowing hot air

by Matthew Sylvain

CAMBRIDGE, Ont. – For the over-the-road owner/operator, a truck is more than a vehicle – it is home. So it only makes sense that it be as comfortable as possible.

For years, truck engines have also served a less obvious double duty: not only do they provide the force to haul heavy loads from pick-up to delivery, but they also power the accessories needed when the wheels stop rolling and a cab’s role changes from cockpit to cabin.

Back in the days when diesel fuel was cheaper and the skies over North America were clearer, idling a 400-hp engine as long as you wanted was an easy solution to your energy and heating needs.

But today, that solution is a large problem, and an expensive one at that. The U.S. Department of Energy calculates that an idling rig burns a preventable US$1,800 hole in fuel and maintenance costs.

Additionally, governments worried about air pollution are tightening emission rules – all while trucks are being loaded with more gadgets, requiring more power than ever before.

It is these factors that make the auxiliary power unit option a bright idea.

These mini-engines power in-cab appliances like microwaves, televisions and laptop computers; and many come with built-in heaters and air-conditioners. They consume only about a liter of fuel an hour, whereas an idling truck engine can gobble up as much as four liters.

Natural Resources Canada, through its FleetSmart program, encourages the use of auxiliaries by truckers to reduce fuel consumption. It is even helping several manufacturers provide a rebate of up to $100 on the purchase and installation of a power unit. These include Espar Heater Systems, Proheat, Webasto Thermosystems, Xantrex Technology and Rigmaster Power.

Adding an auxiliary power unit to a truck, however, is a pretty big investment. Depending on the application, a price tag of $10,000 is common. But, when compared to the cost in wear and tear on a truck’s engine – as well as wasted diesel – the cost can begin to make sense.

Proheat, a unit of Teleflex Canada Ltd., launched an upgraded version of its generator at the Great American Truck Show in Dallas last fall. The Proheat I.C.E. (stands for Independent Cooling and Electricity) Gen2 features a small 13.9 hp, 2-cycle Kubota generator and provides 110-volt AC and 40-amp DC power.

Installation of any auxiliary unit is critical to getting the most out of the system. It’s probably best to trust in professionals, like Ontario-based Cambridge Mack, to handle the work.

One O/O who recently had an APU added to his ’96 Mack calculates that he idles away about 20 to 25 per cent of his time on the road (he asked that his name not be used). Proheat, for its part, claims that its Gen2 unit can lower idling time to as little as two or three per cent.

The Proheat I.C.E. Gen2 system consists of six components: main generator; air conditioning unit; a/c condenser; heat circulation unit; thermostat and control panel.

The main generator weighs 325 pounds and mounts on the truck frame – its housing taking up about 20 inches just to the rear of the fuel tanks – and hangs only slightly lower than the fuel tank. Mounted on the curbside of the truck, this particular installation requires the removal of a side fairing. Cambridge Mack has added hinges to fairings to make servicing the generator easier.

Proheat has fashioned a set of cast-steel clamps that attach the generator to the frame without bolting. The clamps simplify removing and installing, says Ron Wilkem, a Proheat salesman. In this particular application though, the decking behind the sleeper blocked the upper clamps, so instead of cutting notches into the deck’s steel grating, the top of the unit was bolted nonetheless.

The generator engine runs off the nearby fuel tank, hooked to an intake and a return line. It’s also plumbed into the rig’s engine coolant line, using a T-joint under the Mack’s hood, allowing the little Kubota engine to heat its big cousin through a cold Canadian night.

The generator, since it is wired into the truck’s main electrical network, also keeps the engine battery charged. The standard application calls for placing the A/C condenser high on the back wall of the sleeper. However, on this particular Mack, it was mounted on the sleeper’s underside, above the tank and below the bunk storage hatch (which is where the air conditioner went).

The air conditioner has a hermetically sealed compressor and cranks out 12,000 BTUs. Measuring 25-inches long, 15-in. wide and 12-in. tall, it fit easily through the storage hatch. Placing it within the cab helps keep it free of road filth, says Wilkem. Unfortunately, mind you, it meant sacrificing a little cargo space under the bunk, and having it just under the mattress also means the air conditioner is under the pillow.

The placement of the heat circulation unit depends on the truck’s existing lines. Since Mack’s run on the left side, the circulator was tucked inside the frame and a bit forward of the bunk.

The wiring, plumbing, and placing of the ductwork and vents takes up the majority of the time it takes to install the system. Cambridge Mack service-manager Mark Davidson says you’re looking at anywhere from 20 to 30 hours to install, again, depending on the application. n


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