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The Cold Facts

Refrigerated carriers may enjoy a rate premium in the marketplace, but the high cost of equipment can make it difficult to eke out a margin. Finding the most efficient combination between trailer and ...


Refrigerated carriers may enjoy a rate premium in the marketplace, but the high cost of equipment can make it difficult to eke out a margin. Finding the most efficient combination between trailer and refrigerator unit for the application improves the odds.

According to Mike Murdock, trailer product manager at Carrier Transicold, spec’ing the right equipment combination is about trade-offs. The thicker the trailer insulation, the better it will maintain interior temperatures. The refrigerator unit won’t have to work as hard, will use less fuel and last longer. On the down side, the trailer will cost more, have less room inside and weigh more — driving up the fuel consumption of the tractor.

Roger Gendron of Manac, a Canadian trailer manufacturer of trailers, which also produces custom built reefer vans specifically for Canadian conditions, gives an example of some of these trade-offs. “I’m currently dealing with a customer for 15 trailers. He wants to haul for Provigo up North, but he has no back-haul. He would like to use a bigger reefer unit on a trailer with thinner walls so he can back-haul regular freight. Then he wants to know if the shipments are all palletized, does he need a reefer floor? He may not. These are all questions we need to ask.”

In fact, asking questions and fully considering the reefer operation is the trucker’s most important role in the equipment selection process. Then sitting down with both the refrigerator unit and trailer suppliers to analyze the information before buying ensures the most efficient solution. “The best message we can tell the end user is give us as much information as you can and all you want to accomplish,” says Gendron.

This advice is nothing new for reefer fleet managers like Dennis Jan of Byers Transportation Systems Inc. He enlists supplier expertise to help him achieve his primary goal: “Making sure the cooling unit is big enough for the application and the trailer is well enough insulated without giving up capacity.”

What kicks things off in analyzing the operation, according to Doug Lenz, trailer product manager for Thermal King, is the application – is it long-haul or distribution? This defines the way a trailer is set up, whether it will typically run at one temperature or require up to three temperature zones with side doors.

Most equipment suppliers rely on software programs for their thermal calculations. “It loads these factors and climatic information such as ambient temperatures and the trailer requirements, including the type of doors,” Lenz explains.

On the subject of doors, Adam Hill, manager of technical information at Great Dane notes this: “We like roll-up door people. They’re very nice people, very good to deal with, but over-head doors are extremely leaky. It’s the nature of the beast.” Yet a roll-up door offers tremendous convenience for the food service industry in opening and closing while docked and in precooling before loading. The penalty is an additional 10% to 20% in cooling requirement over a swing door.

“The program allows you to look at the worst case cooling and heating requirements. That’s going to let you know which units are in play and which ones aren’t. Then you can start whittling down from there,” says Lenz.

Hill explains what these software programs actually calculate: “There are two technical numbers we look at. The Ua value – which is not an acronym but the value of heat loss – and refrigeration capacity, measured in Btu per hour. The Ua tells you how much heat is coming into the trailer every hour for each degree Fahrenheit difference between the outside and the inside temperature. The refrigeration capacity number tells you how much heat the unit can remove from the trailer… You want to remove 125% of the heat the trailer allows in.”

This extra 25% capacity is needed because reefer equipment performs best when new. “As a rule of thumb, [a reefer trailer] loses about 20% efficiency in the first two years. After that, the losses flatten out at about 25%,” Hill adds. The reason is refrigerant evaporation. The urethane foam that fills the cavities of the walls, floor and ceiling is made up of cells containing a refrigerant – currently 134A. As the trailer rocks and creaks over the highways the refrigerant is released into the atmosphere, leaving only air in the cells, which is a less effective insulator. This is also why non-ozone depleting refrigerants are required.

Reefer units also lose efficiency. As anything mechanical, parts wear, compressors wear, seals wear; dirt and rust accumulate. The compensating excess cooling capacity needs to be considered in relation to the trucker’s reefer contract length and the fleet operator’s trade cycle. Will the equipment be in use four, five, six or eight years?

Availability of service is also a key factor. ThermoKing and Carrier Transicold enjoy what some call a “duopoly” in the marketplace. Both offer extensive customer support. John DeJong of Trailcon Leasing Inc., a sister company to Wilson’s Truck Lines, which leases about 500 reefers, says, “Carrier’s the provider of a lot of our equipment, but we’ve also got ThermoKing and Witby. As far as dependability and fuel efficiency, TK might be better in some areas, but it’s six of one and half dozen of the other. What we’re looking for is if they can maintain the equipment, how expedient they are when they do bring it into the shop and how they stay on top of their service and the PM schedules. Basically, Carrier, on our behalf, has been doing a very good job of that.”

Carrier Transicold surveyed the industry recently to see what is important to reefer haulers. Anthony D’Angelo, director of communications, discusses the results: “What we were hearing from customers was that durability and reliability were key buying criteria. The second was lower life-cycle costs, meaning that it’s not only the purchase price of the unit, but it’s the cost of operating it. The third is product protection — does it control temperature within tight tolerances of set point to ensure product quality. The fourth was ease of use.”

Given the importance of driver turn-over and retention, Carrier is not the only supplier making their units easier to use. ThermoKing has also developed multilingual controls that dial in commodities rather than temperature, reducing operator error and training requirements while maximizing product quality.

Soft issues such as appearance should also weigh into the discussion. Aluminum, composites and stainless steel are expensive but easy to clean. Cleanliness, or the impression of cleanliness, become a competitive advantage in the food hauling industry.

Some forward-looking considerations are noise restrictions, clean air zones and proof of temperature control. “In North America it’s becoming a bigger issue, but in Europe, there’s some legislation that requires that transit information be on file for, I believe, one or two years,” Lenz says. “I think it’s just a matter of time before it becomes mandatory here. If there’s a problem and the person on the front-end and the back-end can prove temperature, but the hauler can’t, he has a problem.”

According to Lenz, investing in data capture while the reefer unit is still on the production line is not only cheaper than a retrofit but can save money in the long run. “The key is looking to the future so the equipment is not just compliant for today — and not just from a legal perspective – but for where they see their business going.”

Satellite, cellphone and radio frequency technology is the other half of data collection. Radio frequency is a short-range communication device that automatically recognizes when the reefer is back in the yard. It automatically downloads all temperature data and flags any problems with the reefer, eliminating the need for manual inspections. The data can then be posted on a website or stored as an e-file.

Satellite communication is a long-range communication device that is gaining in popularity, according to Murdock. “You could be sitting in your office at your PC on the East Coast and you’d know from the GPS exac
tly where your trailer is on the West Coast, what the temperature was set for and be able to tell if the door had been opened or whether the reefer unit needs service. We’ve got over 2000 units equipped with two-way satellite communication systems in service to date.”

According to Lenz, the development of this satellite and cell phone-based technology at ThermoKing is moving in the direction of an exception-based model. The goal is to reduce the costs of managing volumes of data and of transmitting it. “If you’ve got a 100 or a 1000 units out there… [the operator] doesn’t have to sift through hundreds of units to find the problem child.”

Some emerging technologies truckers should look for in the near future are new insulation materials and non-mechanical cooling units. “I think you’re going to see trailers spec’ed with less emphasis on that 125% excess cooling capacity. We’ll make a trailer that will have less degradation. There’s some things that are looking promising in terms of materials,” Hill says, adding that he also hopes to see better performance in roll-up doors.

The CO2-based cooling unit may not yet be a viable alternative in North America because of low diesel prices, but still it has found a niche in frequent-stop delivery applications where mechanical units can’t keep up with cooling demands and in the area of emissions compliance. “The way the system works is we run CO2 from a cryogenic tank through a condensing section. The CO2 doesn’t enter into the compartment… We’ve had moderate success in North America and much more success internationally because, if you look at the cost of diesel fuel in those countries versus CO2, it becomes more attractive.”

The reefer buyer has many options and much to consider. When the trucker does his part — asking the right questions and fully considering his operation — the equipment suppliers can do theirs and present the best combination of equipment for the job.


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