TORONTO, Ont. – Efficiency is key in the transportation business, with fleets and O/Os constantly striving for new and better ways to minimize costs and maximize profits. But reefer haulers may not be aware that efficiency is often squandered when gases trapped in the cell structure escape insulation through a process called outgassing.
Over the years, the insulation components in trailers have become slightly less effective, for a variety of reasons, according to engineering liaison manager at Great Dane, Adam Hill.
“They have become less ozone depleting, as a result they have become less effective,” he said.
However, Hill said that the process of outgassing is common with every trailer, regardless of quality.
“And generally when a customer sees a trailer, it performs its very best on the day it’s delivered and it becomes less effective over the next one to two years,” he added.
To combat outgassing, Great Dane has designed trailers with gradual depletion in mind, so when the trailer is five years old, it will still maintain the desired temperature.
“We try to spec’ the insulation package in the trailer where we can assume about 25 to 30 per cent reduction in efficiency in five years, so that that unit can still maintain those temperatures with that depletion in mind,” Hill said. “So basically most carriers around the country have an overcapacity, especially when the trailers and the refrigeration units are new. Generally 25 to 30 per cent if they’re spec’d properly.”
More recently, Great Dane has come out with a product that lines the interior of the trailer with an impermeable skin designed to stop or significantly reduce the outgassing effect.
“The insulation is still there, it’s just because in the past we’ve had interior skins that were permeable and the outgassing effect was able to take place,” Hill said. “Now we have a product that can stop that process. So the trailer, when it’s manufactured and delivered, will perform the same in five years as it will on the day it’s new or very close to the same performance.”
This higher capacity also ensures better fuel efficiency for both the tractor and the reefer itself.
“(Trailer manufacturers) are always trying to get a lighter and thinner-walled trailer,” said Bill Maddox, application engineer for Carrier Transicold’s truck-trailer division. “To help compensate for that, we’ve been coming out with a higher and higher capacity unit, like our Ultra XTC, which provides for the thin-walled 53-ft. trailers which are mostly standard now today. It’s got higher capacity and better airflow distribution so it can cool the product down quicker. Also, it’s now a standard feature to have a start/stop operation so once you get to a set point, you can shut the reefer down and save that fuel. By having that extra capacity, you can cool down quicker and then get shut down faster.”
According to Carrier, because both the Ultra and Ultima XTC models operate at significantly lower RPMs than comparable models, fuel consumption is lower and engine life can be extended.
“By getting this higher capacity, we have maintained a fairly low RPM for the engine speed,” Maddox said. “Most of our products run at 1,700 RPMs at height speed, and so you’re running at a lower speed and still getting this high capacity.”
For example, at a higher capacity, it might only take a driver an hour to pull down and then shut off.
But if the capacity of the unit is lowered, it might take the driver an hour and a half to get the temperature down.
One of the easiest things a reefer owner can do to keep costs down is ensure constant preventative maintenance is done on the unit.
Some of the major things that can go wrong with the reefer involve the compressor and the microprocessor, according to Glen Tirie, manager of marketing and contract services at Thermo King.
“Those are the two that if they’re properly maintained at regular intervals, they’ll last as long as the life of the unit. But the key is proper maintenance,” he said.
Paul Anderson, director of service and aftermarket business development with Thermo King, doesn’t think mechanical problems with the reefer can be blamed on poor maintenance, so much as inadequate knowledge on the driver’s part.
“One of the main things we see is the unit actually runs out of gas. That seems to be a common problem,” he said. “Usually when you have that kind of issue, it’s because the driver doesn’t know any better or he hasn’t been trained on the unit enough.”
Areas that deteriorate on the reefer trailer itself can lead to fatigue (additional maintenance costs), increased weight and a decrease in thermal performance, according to Wabash National Trailer Centres representative, Craig Sterling.
Two key areas that deteriorate are the floors and the scuffliners.
“(With the floors) wood insulators can deteriorate due to water damage and crushing,” Sterling said.
“A suggested solution would be to use composite insulators that do not absorb water and have a higher crushing strength.”
Sterling says water absorption in the floor can also add weight and suggests using a more impact resistant sub-pan.
New materials like Bulitex can greatly eliminate the damage to the sub-pan and reduce the areas of water penetration, he says.
“As well, scuffliners have long been recognized as the highest damage area of a reefer van. The traditional solution has been to add thickness and height to the scuffliner. But this can prove to be very expensive and will add weight. New composite materials are also being introduced to this area of reefer design. Composites can be stronger than traditional aluminum scuffliners, while saving weight and in some cases cost,” he said.
In order to keep both the driver and the fleet manager up to speed on how all components of the reefer and trailer are operating, Thermo King has developed a program called Thermo King SBT, a product part of the company’s maintenance plan package. It’s designed to track the hours that a unit runs and give a driver or a fleet manager maintenance reports based on predetermined intervals and lets them know when maintenance is due.
While it’s important that a reefer is easy to maintain, it’s really the cost of maintaining the unit that matters in the long run, said Anderson.
“How easy it is to maintain is one thing, but it’s the amount it’s going to cost for to the driver or the fleet manager to make sure that it works, maintains the right temperature and performs properly so it’s not breaking down that’s most important to them,” he said.
Thermo King is constantly working to make things as cost efficient and fool proof as possible for their customers, said Anderson.
“We’re always coming up with new and better technology to make reefers even easier to run.”
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