TORRANCE, CA- Fleets see idle time as a line on a balance sheet or an ECM download. Drivers see it as a comfortable night’s sleep in a temperate environment; a necessity of life in some cases. Reducing idling time, and the associated cost, need not be mutually exclusive goals.

With drivers as difficult to find as they are, fleets that can bring realistic idling alternatives to the recruiting table will have an advantage. No driver today would accept being told they can’t idle to keep warm or cool during their off-duty hours.

Higher fuel costs, stricter environmental and idling regulations, and new technology are driving more fleets to take multi-pronged approaches to saving fuel wasted while idling. However, there are still many fleets without idle reduction policies or technology.

Why aren’t more fleets doing more to cut idling?

“I think in general, fleets are very cognizant of idle time,” says Aaron Peterson, chief engineer of vehicle performance at Navistar. “However, they are also very cognizant of driver turnover. They want to make sure they provide the comfort that drivers expect.”

Peterson says a typical linehaul fleet sees 20- to 30-percent idle time over the course of a year. Some fleets are even upwards of 40 percent, he says.

“A general rule of thumb is every extra 10-percent idle time equates to another percentage point in fuel economy savings,” he points out.

While company drivers may have no choice other than to vote with their feet when it comes to their fleet’s choice of idle reduction technology, owner-operators like Bob Ashe have a bigger stake in their technology choice. Ashe is a heavy-hauler, meaning he’s restricted to operating between sun-up and sun-down. It winter, that means a long time sitting every day.

“I’m running an APU with an inverter,” he says. “We rely on the inverter for the first few hours we’re stopped for watching TV, cooking, etc., and then when the batteries begin to get low, the APU comes on and keeps the system charged up.”

He runs a bunk heater for basic heating needs, but when it colder than usual, the APU provides additional heating and of course AC when it’s hot.

Ashe says the payback on his system came quickly because he spends so much time sitting still. He says the numbers still work in a “normal” freight operation, but the payback will likely come a little slower.

“Sitting with that big motor pounding away for hours just isn’t right,” he notes. “I’m not what you’d call a tree hugger, but I’m aware of the need to reduce emissions. That it saves me money too is bonus.”

While there is a wide range of idle reduction solutions, a full-blown APU that can slash idling to next to zero is not cheap.

“We always encourage fleets to look at the total cost of ownership of an idle-reduction solution,” says Josh Lupu, marketing manager, Webasto Product North America. “This means, don’t just look at the initial cost. Look at the efficiency of the product to really calculate how soon it will pay for itself.”

Payback periods can be relatively short on an APU – less than three years, based on fuel savings alone, says Dean Lande, APU business manager for Carrier Transicold, which offers a diesel-powered APU. Less idling also means less engine wear, he says. “It can mean extended engine life and better trade-in value.”

Following four technologies can help reduce idling in your fleet, and they won’t risk alienating drivers, either.

1. Idle Shutdown

Automatic idle shutdown could be considered the “first tier” of idle reduction. The ability to program the engine to shut down after five minutes of idling (or less) is available from all truck makers.

“Programs such as ambient temperature override allow the engine to idle in extreme low and high temperatures, this is critical for customers who do not choose APUs but still want some idle shut down benefits,” says Mary Aufdemberg, director, product marketing, Freightliner Trucks.

These devices reportedly work well in reducing “accidental” idling, such as when stopping for coffee or a bathroom break. And the ambient temperature override is an important feature to have when some form of climate control is necessary, but that’s still idling.

2. Cab Heaters

Cab heaters are less expensive, smaller and lighter weight than full-blown APUs, but they don’t offer electricity for “hotel loads,” creature comforts such as TVs, computers, etc.

Cab heaters can work by heating engine coolant, much as your truck’s own heating system does, or they can be diesel-fired air heaters. They can be used on their own, or may be part of an electric APU setup.

One diesel-fired unit is Espar’s Airtronic D2 bunk heater. About the size of a loaf of bread and mounted under the bunk, it draws a small amount of diesel fuel from the truck’s tank and runs very much like a home furnace, explains Espar’s Dennehy. “It’s run by a thermostat so it’s just like you’re controlling your heat at home.”

Espar is even close to making available a bunk heater that works on compressed natural gas for truck owners going the route of CNG fueling for their trucks.

Webasto recently introduced what it calls SmarTemp Control, a digital controller that works with Webasto bunk heaters and allows the user to choose the desired bunk temperature.

“Canadians have long recognized the value of cab heaters, as the climate here warrants a heater in a larger percentage of the market,” says Webasto’s Lupu. “We’re seeing real growth now because more OEs are offering their electric HVAC solution that are complimented nicely by an cab heater. For Canadians who need heat more of than cooling, these systems are quite attractive.”

3. Auxiliary Air Conditioning

There are a few cooling solutions without going to a full-blown APU.

Dometic, for instance, has an auxiliary air-conditioning system that runs on 12-volt power from an onboard bank of batteries using an inverter. The batteries are automatically recharged by the alternator whenever the truck is running or from shore power.

While not yet perfect, these electric solutions work well when the truck has the opportunity to fully recharge the batteries, which can take up to six or eight hours of driving at highway speed. Where they fall down is in short-haul operation where there’s not enough opportunity for a complete recharge or with extended downtime, as in when taking a 34- or 36-hour reset.

Henry Albert is an American owner-operator who has been using the Daimler’s ParkSmart HVAC system for several years. He says it’s a very workable solution to idling and diesel-powered APUs, but he admits they have their limitations.

“The new ParkSmart HVAC System offers an integrated auxiliary HVAC system for the sleeper that contains an electrically driven AC compressor and a diesel fired coolant heater,” he says. “Overall, I’m pleased with it, but if you’re taking an extended break, you’ll run out of battery power unless you’re plugged into shore power. When the temperature is extremely hot outside, there’s only enough capacity to keep the sleeper cool, you can’t do much else that require electrical power.”

4. Auxiliary Power Units

There are two main categories of APUs: Traditional diesel-fueled and those that use batteries/electricity.

The big advantage to a diesel-powered APU is that, spec’d properly, it can handle just about any hotel load drivers throw at it on top of heating and cooling needs. On the downside, it’s still using some amount of diesel fuel, even though it is much less. And they require diligent maintenance.

Many fleets have reported high maintenance costs for APUs, especially the traditional diesel-fueled ones. APU manufacturers are working to address that. Thermo King, for instance, offers improved diagnostics and a new 2,000-hour extended maintenance interval on its TriPac Evolution APU.

Several owner we spoke with suggested expensive synthetic engine oil made starting easier in cold temperatures and extended the maintenance intervals. But in the end, these things live in a pretty hostile environment.

Electric APUs are quieter and they aren’t adding another diesel engine to the truck, with its additional fuel use and maintenance costs, but they have limited capacity because of battery life. If plugging into shorepower is an option, these things shine. But there’s still pretty limited availability of electrical plug-ins in the U.S. and they are non-existent in Canada.

Navistar’s MaxxPower APU, for instance, will monitor the battery charge and engine oil temperature. At programmable thresholds, it will automatically start the truck in order to recharge the batteries. This typically takes about 70 minutes, Peterson says.

Freightliner’s ParkSmart is now available with something similar, called Opt Idle. ParkSmart monitors the temperature in the cabin, using the batteries. Once the batteries reach a low level, Opt Idle will start up the engine to recharge the battery, proving unlimited ParkSmart run time. But again, we’ve got some engine-on time, and that can contravene some local idling ordinances.

We still don’t have a perfect solution for maintaining driver comfort without some external source of heat and power, except maybe hotel rooms.

The technology is improving and options are expanding. At the same time, the pool of drivers is dwindling. So, APU or no APU may no longer be such a tough decision.

If you want to keep your trucks moving, you have to keep your drivers warm (or cool) and happy.