Cooling It

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With customer demand for ‘greener’ technology on the rise, plus pressures within companies themselves for reduced carbon footprints and cost control measures, there’s no shortage of factors to consider for fleet managers running reefer-equipped vehicles.

John Sheikh, a reefer leasing specialist with PLM Train Trailer leasing, says that challenges to fleets using climate control units aren’t few: the need for reliable performance, product integrity, the reduction of trailer downtime, increased driver productivity, lower maintenance costs, fuel economy, the reduction of carbon footprints, and an increased profit margin.

But the true cost of running these units relates to fuel, said Sheikh.

“Carriers are making good strides towards hybrids but are not there yet,” he said, cautioning that hybrids are not to be confused with electric vehicles.

“Hybrid vehicles offer two different energy converters, and two different energy storage systems on board for the purpose of vehicle propulsion,” said Sheikh.

Rick Boily, district service manager with Thermo King, says his company has several options in terms of alternative climate control available now, and is currently testing others for use down the road.

The B100 is an all-electric, temperature control unit, for fresh food application in small vans. With low amp consumption, the unit requires no added compressor or vehicle modifications, is strictly battery powered, and offers road and electric standby operation as an option.

The company’s new T-series, to be launched in the next few months, uses a hybrid smart power option.

“Its exterior skin offers 50% reduced noise with a honeycomb grille that directs noise upward. Panels are made from recyclable geloy plastic,” said Boily, adding that the unit has a robust construction that hides scratches, and offers one body hole size and one bolt pattern for all units.

The T-series offers a Tier 4 diesel engine that runs 10% better on fuel, and has an EMI 2000 filter that reduces waste.

“The hybrid smart power electrical operation has a next generation TK 04 and TK 06 scroll compressor, and the same SR2 controller board that’s been used in trailer application since 2004. There is more parts commonality,” said Boily.

The T-series also offers stationary ‘Over the Road’ hybrid smart power.

“We’ve developed and are testing a smart power option that inverts DC voltage from lithium batteries to AC power. It will have diesel, hybrid (that can run while the truck is running) and shore power. The unit will also auto switch between modes based on ambient and power supply requirements. It will be smart enough to know which is the cheapest way to go, whether it is plugged in or driving,” said Boily.

By running on electric standby power, and by plugging in the unit at a distribution centre instead of running on diesel, you could save some 71% of your overall costs, based on diesel at seven cents a gallon and electricity at nine cents per kw/h, he noted.

“This doesn’t include the savings you’d get on the maintenance of your engines. This is an option that was very popular in the ’70s and is coming back,” said Boily.

Cryogenics, a technology that’s been offered in Europe for a while, and is being tested in California, offers no engine emissions, and silent and reliable technology, he said.

“Liquid carbon dioxide moves from the tank through an evaporator coil inside the cargo area. Air circulates over the coil. After useful energy is extracted from the carbon dioxide, vapour is exhausted into the atmosphere, and heat generated by the vehicle engine coolant.

“It’s ideal for distribution purposes. There are fewer moving parts, and rapid temperature recovery. There is no refrigerant but you have to fill up the tank daily and get about an eight-to 10-hour use, depending on the tank size. You have to weigh the initial cost against your long term gain,” said Boily of the technology.

Tripac, another technology that’s been out for about four to five years, offers a 1000-hour maintenance interval.

“You can put it in sensing mode so it doesn’t work during out-of-service days. It has automatic start/stop for maximum fuel economy,” he said.

Fuel savings in the future will most likely be achieved through cryogenics technology, electrical engines, compressor technology, hydrogen power fuel cells, and ‘super insulation technology’ that would save gallons of fuel through better thermal insulation, said Boily.

Wayne Scott of Loblaw’s said the company has some 2,000 reefers in Canada, with each running about 10 hours a day. They are looking at two areas of opportunity to reduce their carbon footprint: trailer refrigeration and DC/trailer refrigeration.

“The vision has to be ‘top down’ and there has to be a culture in place. Within our 910 million kg of carbon dioxide footprint in 2008, 25% of that footprint is based on refrigeration,” he said.

Companies like Loblaw’s that are heavily involved in distribution functions with high cube requirements, can only go so far in terms of gaining thermal efficiency through trailer walls, roofs, and sealings, given the fact that thicker walls and sealings won’t fit as many skids.

The company is partnering with Sunwell Technologies to eliminate the diesel engine out of reefers with “deepchill thermo battery refrigeration,” and reduce the amount of refrigerant gases used in their distribution centres.

The technology involves setting up chilling stations at DCs set at the temperatures required for grocery distribution. Thermal storage tanks can hook up to a trailer, then the tanks are plugged in and will maintain the temperature as they cycle through, said Scott, who noted that Loblaw’s wants to reduce its carbon footprint by some 3%.

“This product can maintain 96 hours at a constant temperature of -6 degrees Celsius, with most distribution centre deliveries taking between a five-to six-hour or less delivery window. I’ve got a lot of reefers in the marketplace right now that are single and multi-temperature. I can put this technology into all types of units or I can leave it empty and use it as a dry box. Part and parcel of this is if I can take this into a DC as well, I can use it in my cooling chambers or freezers, and it results in one-tenth of the former refrigeration needed at a DC,” said Scott.

With electric standby reefers, there’s still an electrical carbon footprint, but depending on how electricity is generated where you’re using it, this footprint can vary, he said.

“I can pre-charge this and shut it off, and benefit through a reduction in utility costs when utility rates are high,” said Scott, who noted that Loblaw’s is looking at acquiring 30 to 40% more equipment offering hydro-only or hybrid power.

Jim Clarke, executive account manager for Carrier Transicold, said that when looking at some of the proposed alternatives to climate control, there are still some technological hurdles to overcome with regard to power, limited ranges, cost, and weight issues.

Hybrid reefers, however, could offer a real advantage in terms of savings, he said. There are fewer parts to contend with, there is higher reliability, high system efficiency, and electric standby power. They also have less environmental impact.

“At their core, today’s conventional systems are mechanical. When you adapt these systems through various components to run electric standby equipment, it adds additional weight and complexity, and additional maintenance items,” said Clarke.

Hybrid technology is specifically designed with an all-electric architecture, with reliability in mind, to eliminate moving parts, he added.

“A hybrid unit eliminates many of the maintenance elements of mechanical transmission components, such as drive belts, fan shafts, compressor drive shaft, shaft seals, and centrifugal clutch mounted on the compressor of the conventional standby unit. A multi-temperature hybrid unit shows a 30% decrease in maintenance costs. It also only runs when it needs to, so it saves fuel. With a conventional unit, once the engine starts, every component (i. e. compressor, evaporator fan, condenser fan) runs, whether you want it to or not. Hybrids also use 33% less refrigerant, and have 50% fewer brazed joints,” said Clarke.

While use of hybrid units offers the promise of maintenance savings and lower fuel usage, batteries themselves have their own footprint.

The life span of a hybrid lithium ion battery will depend on how far you deep cycle it, said Boily.

“It might have 400 cycles. What kills batteries is the cycling. Your best option is to keep that battery efficient, keeping the voltage as constant as possible,” he said.

The longer the battery can be kept in service, the ‘greener’ its footprint.

“There is technology that is more expensive, for example the EON Thermo King that contains no acid. It’s completely dry and has a four-year warranty replacement. But the typical battery today will run one-and-a-half to two years at best,” said Boily.

With regard to what issues might arise if electricity costs spike, as they already have in places like Europe, “It’s a struggle everyone has to deal with,” said Boily.

Boily and the others mentioned in this article were participants at the 46th Canadian Fleet Maintenance Seminar discussing options on the table for alternative climate control that reduce fuel consumption and harness renewable energy sources.

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