Rolf Lockwood

January 16, 2008 Vol. 4, No. 2

Most of the announcements about on-board power systems lately have been along all-electric lines, what with new or impending laws about emissions from even the little one- and two-cylinder engines that run auxiliary power units. Kenworth’s CleanPower option comes to mind, for instance. But there are still dozens of genset-style APUs out there, and now we have a new one from an interesting source – an off-road HVAC specialist.

Tridako Energy Systems, which has been building HVAC systems for those monster Terex trucks and the like for 35 years, has turned its hand to on-road auxiliary power. Its
PowerCube, the lead item in this issue’s product group, looks pretty intriguing, and given its heritage, I’d guess that it will offer the reliability that buyers say has sometimes been lacking in the APU world. That, I should rush to clarify, is just what I said – a guess. I simply figure that experience in building HVAC systems for the rough-and-tumble life of a big Terex or Case or Volvo off-road truck will result in smart engineering of the design details in an over-the-road APU. For example, the engineers decided not to use a V-belt drive. Instead, the PowerCube’s drive belt is flat and notched, with a tension-mount spring pulley.

The PowerCube is not the smallest unit out there, needing 31 in. of frame space, nor is it the simplest. But at six hours, installation time isn’t bad, though that assumes expert hands qualified to work with R134a refrigerant. It sure does pack some power – 24,000 Btus on the cooling side, 30,000 for heating. It’s completely self-contained, needing no integration with truck systems, though its AC condenser is located in the main engine compartment.

It meets current Tier 2 CARB emission standards, and when Tier 3 is enforced, the company will offer a retrofit muffler option — a four-bolt, 10-minute changeout, they say.

Tridako claims, by the way, that the PowerCube is the only APU that undergoes SAE-certified J1503 testing, and actually meets the standard.

And the cost? Very reasonable at a suggested retail of US$7999, though there’s a special offer until March 31, at a factory-direct price of US$5999.

There’s no dealer/distributor network for the PowerCube, at least not yet, but Tridako will arrange for installation at a place of your choosing. If you’re interested in knowing more, I included the company website’s URL in the item below as always (, to repeat myself) but I found the site to be working less than perfectly today, with some of the links to brochures and manuals not functional at all. I’ve learned that it’s only been up for two days, so have patience. For the moment, you might do better on the phone — 308-762-3235 in Alliance, Nebraska.

By the way, Tridako is on the lookout for a distributor.

ELSEWHERE, FEDEX GROUND IS TESTING A HYDRAULIC HYBRID in partnership with Parker Hannifin Corporation. Details are a bit sketchy at this early point, but the vehicle in question is a class 6 truck and the aim is to improve fuel mileage by more than 50% while chopping engine emissions significantly. Initial EPA simulation modeling of city driving confirms that 50% figure.

The truck will rely on a Parker series-hybrid hydraulic drive that eliminates the conventional transmission, along with its weight and maintenance, while improving drivetrain power density. There’s nothing like the power produced by a hydraulic system.

“Primary pump/motor components developed by Parker leverage additional technologies developed by the EPA to create a true series hybrid drive as opposed to a parallel system that would increase vehicle weight,” says a joint press release. “The system captures, stores and deploys energy by recovering inertial energy and optimizing engine efficiency, using Parker hydraulic technology.”

As it happens, Parker has been developing hydraulic drive systems for commercial vehicles for some 10 years. The company sure has credentials in the hydraulic world, and
the FedEx truck will sport “a full suite” of its products, including technologically advanced pump/motors, hoses, fittings, valves, electronic controls, and high-efficiency accumulators.

A working demo vehicle should be ready for FedEx within the next 12 months, but the technology will have applications elsewhere, and with other classes of vehicles.

The hydraulic option is also being explored by Eaton, along with Peterbilt on the heavy side and with Ford in the light-duty world. It seems like a promising option to me, being simpler and cheaper, though the hybrid electric alternative seems to be running away with the trophy here. Maybe this new partnership will prove me right.

SPEAKING OF ADVANCED TECHNOLOGIES, I had an interesting e-mail from a Product Watch reader just before Christmas in response to my December 19th newsletter. Some of you will remember that I bravely did the crystal ball thing and opined that variations on the stability control theme would take off this year. With systems from Bendix, MeritorWABCO, and Haldex out there, well established in technical terms, I think that truck operators will soon embrace them – even before they’re mandated by law, as they surely will be. And should be.

Rolf Lockwood

Rolf Lockwood is editor emeritus of Today's Trucking and a regular contributor to

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