Refrigerated transport – a matter of life and death

By Ilana Koegelenberg
We chat to local industry stakeholders to learn more about the very crucial transport link in the cold chain. From standards to trends and even useful advice – we explore all things refrigerated transport.


As we continue our exploration of the various links of the cold chain, we get to the very important link that is transport refrigeration. (If you haven’t done so already, check out our preceding features on the producer, retail, and processing links in the chain.)

Refrigerated transport often comes into the cold chain at more than one point as the product gets moved from producer to consumer. And it’s during this link that the product gets exposed to a variety of different elements such as weather, ro
ad conditions, and mechanical failures. All of these have major contributing factors to the successful delivery and sustainability of the cold chain.
The refrigeration system is a combination of the insulated body and the refrigeration unit. Together the two must maintain the cold chain for the transporter. “The object is to keep the product at the correct temperature from point of loading to point of dispatch,” explains Peter Solomon, managing director of Transfrig (a Valeo brand).


But is refrigerated transport really that important?
“Correct and proper refrigeration and temperature control is important as it prevents the ageing of the product during transit,” explains Pieter Swart, head of sales transport cooling – southern and eastern Africa at GEA. This also stops and slows the respiration of the product, which produces more heat if not maintained at the correct temperature. Failure to keep the temperature regulated causes premature ripening while in transit, and also reduces shelf life when delivered to the retailer. “Food waste is aided by poor refrigeration, increasing the cost unitarily to the consumer,” says Swart.

Temperature fluctuations affect the appearance and taste of fresh products in a variety of ways. For instance, if ice cream melts or fresh product is frozen, the product will be ruined, Solomon explains. A more serious issue arises when products are stored at temperatures that are too high. This is when illness-causing bacteria, which exist naturally all around us, can begin to grow more quickly.

“The risks include writing off of stock that is not fit for consumption, returns by customers (which leads to a loss of earnings), and consumers possibly getting ill, leading to damage to a brand’s reputation,” explains Clinton Holcroft, managing director of Serco.

"Perishable products do just that – they perish!” says Cliff Marks, managing director of SC Bodies. “The lifespan of these products can be increased by changing their temperatures and keeping those temperatures constant. Much research has been done worldwide in this area, and it is fast becoming law internationally to maintain the cold chain.”

“I think the transport link is one of the most important and most complex links of the cold chain,” explains Kenan Gröss, managing director of JAVGR Refrigerated Transport Solutions. “Should that link be broken, the food stands a chance of being spoiled and thus poisoning the consumer and causing illness and even death.”

Horses for courses

What types of refrigerated transport options are available and what factors should be considered when choosing
a solution?
There are commonly four types of transport refrigeration systems available, explains Solomon.

  1. Direct drive: The refrigeration compressor is driven directly off the vehicle crankshaft and will therefore only provide refrigeration while the vehicle engine is running.
  2. Diesel-electric: Units that have their own diesel engines and electric motors and are therefore totally self-contained and independent of the prime mover.
  3. Eutectics: A holdover or latent heat storage system. The completed unit comprises a 220V single phase or 380V three-phase condensing set coupled to eutectic beams or plates mounted internally to the roof of the body. The system is plugged into an electrical supply until the beams or plates have reached the required temperature, unplugged and the vehicle then used for its delivery round.
  4. Cryogenics: Liquid nitrogen is stored in a tank under the truck or trailer. When a valve is opened the nitrogen passes through pipes in the side walls to evaporators mounted in the roof. The system is then used like a conventional blower unit. The nitrogen is discharged into the atmosphere. CO2 cryogenic systems are also available.

There is also ongoing development of solar and all electric unit options.
It is important to establish which type of refrigeration system is best suited to the customer’s needs, explains Solomon. “It is essential that we understand precisely what the user of the transport refrigeration system requires and then provide the correct solution.”

Typical information required:

  1. The product that is to be transported.
  2. The temperature required.
  3. The loading temperature of the product.
  4. Body dimensions.
  5. Insulation material and thickness.
  6. Trip duration.
  7. Number of door openings per trip.
  8. The ambient temperature where the vehicle is operating.
  9. Pull-down period (Eutectics only)

When looking at the trailer itself, the distinction is between reefer semi-trailers (pulled by a tractor) or a rigid reefer vehicle (non-articulated), explains Günther Heyman, sales executive of GRW. Within these groups there are multiple different options with regard to body lengths, cooling unit type, door types and pallet quantities, load securing and more.

Also, there are a variety of panel thicknesses to suit the various temperatures required for the different products, explains Holcroft. Broadly this hinges on the product being transported and falls into the categories of deep frozen, frozen, chilled, or ambient ranges.

“The right option for the job is totally dependent on the application,” says Heyman. For example, if you are doing secondary deliveries with multiple drops at smaller, tight delivery points, a short vehicle or rigid reefer would probably outperform a big 30 pallet semi-trailer. If you carry part frozen, part dry/fresh goods, a multi-temperature set-up would serve your needs better. “Because of this, it is important to engage with your body and trailer builder to make sure the correct and best product is specified.”

There is no shortage of options. Fully insulated truck and trailer bodies at any temperature discipline are available. You can even run multiple temperatures in a single truck or trailer. There is no excuse for making poor choices, says Marks. “There is no point in fitting a fridge unit into a poorly insulated body to save costs. It does not work, and legislation is spreading to the food manufacturers, who are already refusing poorly insulated vehicles from transporting their products. The right equipment is available!”

Standards and regulations

Health and safety standards and Hazard Analysis and Critical Control Points (HACCP) are some of the regulations relevant for refrigerated transport. Recently, ATP-certification for the bodies has been introduced, but this is optional and not a requirement, explains Holcroft.

“In South Africa, we find that food manufacturers are setting their own standards, are applying their own quality rules, and are managing these in their own way! This often ends in non-compliant transporters being turned away,” explains Marks.

Transporters generally check the temperature of the goods when loading; thereafter they should monitor in-transit temperature to ensure it remains within the parameters set. The use of telematics systems to record temperature has become standard with many transporters.

If the operator does not know whether the cold chain has been broken or not, this could be a huge risk, explains Heyman. “The financial/legal penalties for delivering products that have been compromised can be enough to close a major business.”

More and more of the fresh retailers are starting to put measures in place to record the full cold chain and the transporters will be required to prove that the cold chain has not been compromised, says Heyman. This is where telematics will make its mark.

“I would estimate that about 30-40% of refrigerated vehicles today have telematics. There will probably be 100% within the next five years,” Solomon predicts.

Common mistakes

What are common mistakes made when designing and manufacturing a refrigerated truck body?

The most common mistake is ignoring all the possible heat bridges, like steel/ aluminium cappings, which are present inside as well as outside the body while being connected, explains Gröss. This allows for the heat from outside to find a way past the insulation and enter into the body.

The insulated body should minimise the heat leakage through the body to keep the load within commercial limits, says Solomon. “As a guide, the rate of heat leakage should not exceed 0.4W/m².” Prevent a detrimental increase in product temperature for a minimum period of eight hours in the event of a failure of the refrigeration system, according to the South African Refrigerated Distribution Association (SARDA) code of practice.

Another mistake is to use cheaper and inferior insulation as well as go thinner on the insulation thickness. This, again, has adverse effects on the cooling performance, he says. “Also very common is the incorrect or poor assembly of the body which in time allows for moisture ingress and thus reduces the insulation performance,” says Gröss.

Proper insulation and wall thickness of the refrigerated truck body is not always specified correctly for the temperature requirements by the client, which means that heat loss through the insulated walls is much higher, resulting in temperature losses and the refrigeration units working harder to maintain the required temperatures, explains Swart.

If the vehicle body manufacturer does not understand the customer requirements and operating conditions, it is possible the body can be incorrectly specified, adds Holcroft. “Also there is cost pressure on vehicle body builders and they can compromise by reducing thickness of the insulation, using lower density foams, or using polystyrene insulation which has lower thermal properties than polyurethane to save costs.”

It is a huge mistake to not understand exactly what the customer needs to do with the truck, explains Marks. “Often the end user will purchase through a third party, i.e., a truck dealer, or a transport consultant, and their exact requirement is not communicated to the body builder.”

Most of the time the only mistake on the insulation side happens when there is a misunderstanding between the client, dealer and the manufacturer, explains Marco Martinelli, director of Dalucon, manufacturer and supplier of insulated panels.

Another issue is that appropriate and correct refrigeration unit selection is overlooked at times, causing units to be underspecified with regards to capacity requirements, says Swart. This results in equipment working continuously instead of shutting down faster on setpoint. As a result, refrigeration equipment is operating more than required, causing an increase of fuel consumption, and more CO2 emitted in the atmosphere, which aids global warming.
“The refrigeration unit must be selected to ensure that it has the capacity to keep the product at temperature, taking into consideration the ambient temperature, required product temperature, and the number of door openings during the trip,” advises Solomon.

According to Heyman, another big mistake is underestimating the harshness of the South African transport environment. This is particularly true about the loading and offloading processes, with under-qualified and low-paid personnel, as well as the condition of our roads and questionable receiving bays. “Load securing is also not a high priority in South Africa and thus product and body damages are common,” he explains.

Improving efficiencies

How can you improve efficiencies and energy usage on insulated truck bodies for refrigeration?

The body and the refrigeration system form an integral unit that must provide the correct solution for the transporter, says Solomon. “It is therefore extremely important that we match the fridge and the body correctly.”

He advises:

  1. Ensure the correct type and capacity of unit is correctly specified. Be sure the unit is not underspecified and although over-specifying is often a good option, this may result inefficiencies.
  2. Ensure that the unit is serviced as specified by the manufacturer, kept clean and in good running order.
  3. Ensure the box is correctly specified and kept in good condition.

The two most important aspects of efficiencies when it comes to truck bodies are correct design (such as no heat bridges) and the use of good quality materials (such as high quality polyurethane insulating foam), explains Gröss.
You can also use a reflective paint or tape on the roof and floors to reject the radiation coming in from the sun and tar surfaces. “This will reduce the potential heat load entering the load body, which will ultimately cause the cooling unit to work harder and use more fuel,” according to Gröss.

“Thicker insulation is also always a guaranteed way to increase the efficiency of the body. It may not always be practical, but definitely more efficient,” says Gröss.

Heyman suggests using better quality, more efficient panels that offer superior insulating properties, resulting in less energy to keep the inside of the vehicle at a given temperature.

Swart also agrees that insulation is key. “Correct or slightly over specified insulation should be used,” he suggests. Improvement of the insulating foam with enhanced properties aids temperature control. “Improved temperature control results in less energy required to maintain temperatures.”

But it’s not just about the truck itself. “A major source of energy wastage is at the delivery points,” explains Heyman. There are many occurrences where a load gets to its destination, but then has to wait anything between one to four hours before being offloaded. “By investing in resources to improve this aspect there could be major efficiency gains.”

Another issue at the delivery point is the level of supervision and the personnel’s understanding of the cold chain. Too often the refrigeration bodies are opened and left open for too long, and to worsen the issue, the cooling units are left to run while the doors are open, says Heyman. This should not be done as the cooling units will blow out the cold air and warm, humid air will be sucked into the unit, and then the air inside the body is hot and contains a lot of moisture again. It then takes much longer to get the body down to temperature again.

Holcroft recommends frequent servicing of the fridge and the body to ensure repairs are done timeously. He also suggests: installing air curtains on the doors to reduce cold air loss when doors are opened, installing insulated load dividers to separate products with different temperatures, and/or installing temperature telematics systems.

Maintenance matters

Speaking of ‘frequent servicing’, how important is maintenance on the truck and why? Is this being done properly in South Africa?

“Considering the state of some of our roads, maintenance is very important,” says Martinelli. Hairline cracks in the sub-frame and door frame can be detected and fixed early.

“Maintenance is paramount to the life cycle of the truck, and is more important to the body,” explains Marks. Most users wait until the body is rejected at the loading bay before they have it repaired, and then it becomes a repair job, instead of routine maintenance, and is expensive. Non-maintained bodies are also dangerous in hygiene aspects. Fungus gets into damaged areas and grows, and can contaminate the product.

“Maintenance is definitely very important when it comes to any mechanical devices, however for cooling units it becomes highly imperative,” says Gröss. This is done for obvious reasons, like when experiencing a mechanical failure on a cooling unit the proverbial clock is against you. You either have it repaired immediately or find a suitable nearby cold room to have the product off-loaded and preserved.

When it comes to the refrigeration unit itself, like any mechanical equipment, regular service and maintenance are key, says Solomon. Under most circumstances, the fridge unit runs longer hours than the truck. The units runs overnight as well as at times during the delivery cycle when the truck is off. “This emphasises that the unit needs at least the same attention as the truck when it comes to service and daily checks.”

“Transport refrigeration technicians require a high level of skill and it is important to have qualified people servicing the units,” says Solomon. “Transport technicians not only need to know the refrigeration system but also be able to repair and service diesel engines as well as be competent electricians.”

“Maintenance or rather proactive, preventative maintenance is as important as any effort to prevent ‘dropping’ loads or ensuring loads are delivered on time,” agrees Heyman. “Effective maintenance is an art form, with the emphasis in not taking shortcuts and doing the basics right.”

Without effective preventative maintenance, unplanned downtime creeps in, and with that, additional costs embedded in ‘standby vehicles’ or additional sub-contracted work (and cost) necessitated by the need to meet customer commitments and promises made.

Normally during breakdowns (caused by lack of maintenance), the technicians are placed under serious pressure to try and repair or at least get the cooling unit to run again, explains Gröss. “This normally leads to shortcuts as well as dangerous bypasses just to get the unit to temporarily run again. This, in its entirety, is not a bad thing, but where the issues arise is the fact that no one goes back to fix the ‘temporary fix’ and so the overall health and wellbeing of the machine diminishes over time and either starts a chain reaction of problems or becomes dangerous to operate.”

“Companies and organisations who are able to manage an effective maintenance regime also positively affect the ability to plan operations
and ultimately improve the overall quality of life of all employees involved,” says Heyman.

“At the moment in South Africa, I would say that maintenance is not being done to its full potential,” says Gröss. This is mainly due to the shrinking maintenance budgets of companies to keep them on the road, and not adhering to the proper maintenance and service schedules. Lack of training for technicians is also a major contributing factor in not having the units serviced correctly.

In South Africa, the extent to which effective maintenance is being done varies significantly, and often varies in direct proportion to the size of the fleet involved, which should come as no surprise, says Heyman. However, it’s still a rather common problem that workshops and technical staff struggle to gain access to vehicles due to the on-going pressure to generate sales, preventing operations from making vehicles available when due for service.

On the upside, there are examples of leading companies where the need for preventative maintenance is understood and valued at the highest level of management and supported by experienced experts in the field of maintenance. “These companies have shown that is possible to implement a robust maintenance regime and in turn achieve superior vehicle reliability and vehicle up-time, which sets them apart from their competitors in the long run,” says Heyman.

It’s not just essential to do maintenance, but to also ensure it’s done right. “It is important to use a reputable repairer to insure the work is done to a high standard,” advises Holcroft.

A word of advice

The stakeholders share some advice from their experience on things to look out for when purchasing a refrigerated truck body, trailer, or refrigerated unit.

“Firstly, I would say the transporter needs to know their product, their delivery routes, as well as their delivery schedules,” Gröss advises. This will all contribute to which type of body and cooling unit he will need. Most people just buy on face value price (cheapest) which can bring some immediate cash flow relief, but will always end up in an inefficient recurring cost when your maintenance or diesel costs stay high in a competitive market.

Always look for good quality insulation and proven technology offered in the market, advises Swart. Also, be mindful of low-priced and less expensive bodies. Quality products can be costly but will give you the result you require.

Good quality door seals and locking equipment are very important. Gröss agrees: “Make sure all door seals are in good condition and seal well. A large percentage of cold air is lost through damaged or missing door seals.”

Swart also recommends proper load positioning devices for airflow around and underneath product, which will assist with temperature control.

Then, insist on greener gasses, Swart says. High Global Warming Potential (GWP) and Ozone Depleting Potential (ODP) gasses are still offered in the market, so enquire and insist on new and better equipment that uses refrigerants with lower GWP levels. “It is important that we all work towards using equipment with latest technology conforming to international standards with regards to greener initiatives.”

Check to see if your body is certified for frozen and fresh loads or only fresh loads, Gröss advises. There are many companies that buy new or used bodies on price when they should actually be asking can I use this “chiller body” to transport ice-cream? Also do some homework on the manufacturer, see what their quality is like and ask around in the industry.

“The best tip is to use a reputable body builder,” advises Martinelli. “The client should visit the body builder’s premises to ensure best practices are followed, especially if it’s the client’s first time buying a refrigerated body.”

If you’re buying second-hand, have the truck weighed at a local weigh bridge and compare the weights to its registered weight, says Gröss. Many times as bodies age they take on water within the walls and insulation, which not only reduces your load carrying capability, but also creates an issue when trying to freeze past zero in a short time span, due to the eutectic phase of water as it freezes.

If possible, you can have the body photographed with a Forward Looking Infrared Red (FLIR) Camera, which will immediately highlight any cracks within the body walls as well as any water that has ingressed into the insulation. The FLIR cameras will also highlight any potential heat bridges like aluminium cappings used to finish off door edges as well as body bolts going right through the insulation to the outer surface.

“Invest in the latest technology for improved efficiencies, durability and lowest life cycle costs,” advises Heyman. In refrigerated vehicles the saying of “penny wise, but pound foolish” is very true. “Make sure the specification is fit for purpose.”

“I believe it is just as important for a transporter to watch the body manufacture process, as it is to understand the truck’s technical capabilities,” says Marks. “All too often price is the major concern, and the technical capabilities of the body is ignored.”

Local vs imports

Imports vs. locally manufactured – what is the difference really?

“This is normally a difficult question, as both have their pros and cons,” explains Gröss. For example, the imported units are all ATP-tested and deliver the exact cooling capacity they are advertised to have. They are also subjected to much longer and harsher testing procedures, which allows their engineers to see what components will fail first, thus giving them a looking glass to rectify any potential problems before they occur. “This, however, has a big price tag on it and thus chases a large portion of the local market away.”

The local units also have an advantage in that their engineers sit locally and thus can change the design to suit their customers’ needs rather quickly, says Gröss. They can then also choose which tests they would like to have done, ultimately tailoring the price that suits their customers’ needs.

“The quality of the imported units is normally a bit higher than the local units as the first world countries tend to implement latest building and manufacturing processes quicker than the local unit manufacturers,” says Gröss. This includes welding robots, automated PC board production lines, anti-corrosive coatings on all exposed surfaces ... and so forth. “The quality ultimately determines the length of time the unit can survive in our harsh South African conditions without continuous maintenance,” — in other words, from scheduled service to scheduled service without breakdowns.

“The imported units are normally a bit more expensive upfront but then have a reduced operating cost, providing the manufacturer’s service schedule has been followed,” Gröss says. “The local units are cheaper to purchase, but then tend to have more failures in-between services, which tends to drive the operating costs up.”

“The biggest difference is that our local market is too small to warrant the investments needed to be at the forefront of the latest technologies and advancements in the refrigerated market,” says Heyman. International markets have much higher volumes, but are also fiercely competitive and the international manufacturers thus have to invest to gain even the slightest advantage. “This would not be possible for a local manufacturer, as they cannot achieve the economies of scale needed for new technologies at a reasonable price.”

According to Swart, the life span of international equipment is proven to be longer. “In-depth engineering and time spent testing equipment proves international products to be superior to local,” he says. The research and development that go into internationally manufactured equipment is much higher, with European standards changing so fast and pressure to comply with new global laws, so you are able to use equipment that conforms to the highest international standards.

Another advantage is that international products can be used globally and are certified for operation, e.g. ATP tested equipment is certified by an independent authority, explains Swart. The data published by the international manufacturer is factual and cannot be published to the industry with the intention to benefit from results under less stringent testing conditions. Local manufacturers are not subject to an independent authority testing to verify the data published. “The results obtained under different environments and testing done under less stringent conditions than those under international standards could be questionable and biased to say the least.”

There is more than one side to the story though. “International products are based on differing countries’ legislation, and may be completely useless to our market,” explains Marks. “Most countries that we follow technically have similar temperature requirements to ours, but their ambient properties differ to ours, and cause us more problems.”

Imports are expensive, and as explained above, follow different temperature regimes, says Marks. “We need to spend more energy studying our local needs, and gearing our manufacturing abilities to local factors.”

Imports are very costly and could take six to nine weeks to ship and clear customs, explains Martinelli. “The best is to support local!” Besides the price and manufacturing time advantage, you are creating employment and the whole value chain benefits from suppliers of raw materials. “The biggest advantage is that if there is something wrong, there is local guarantee and warranty. I want to see an overseas company come all the way to South Africa to fix a faulty door.”
In the end, it is important to partner with a reputable supplier who is knowledgeable about the options available as well as having a reliable after-sales service to support their product, advises Holcroft. The body manufacturer should also be staying abreast with the latest technology for panel manufacture and the accessories available to suit the customer’s requirements. The recent introduction of an ATP test station means transporters can demand their manufacturer produce evidence of compliance. “This cannot be manipulated and provides peace of mind that standards have not been compromised.”


What are some of the current trends locally and internationally for products and technology in general?

At the moment there is a great drive in the cooling unit world to try and bring down the “Global Warming Potential” (GWP) and carbon footprint of the overall operation of the unit, explains Gröss. This will include using new technology refrigerants and also powering the units from alternative power sources like lithium-ion batteries, which can be charged via green and clean energy sources like wind and solar.

“The trend is towards more efficient equipment and the reduction of carbon emissions, global warming and the greenhouse effect,” agrees Solomon. Also, insulated body builders are working on improving the heat leak factor of bodies. This will result in a lesser refrigeration requirement and, in turn, improve efficiency.

Liquid nitrogen with zero on road emissions has been introduced to the South African market as a cryogenic option, says Solomon. Manufacturers are designing and prototyping different options in the development of transport refrigeration equipment.

Lower GWP refrigerants such as propane have been tried and tested in South Africa and will be rolled out in the future. Various hybrid options are now available and others are in the development stage. Also, some manufacturers are in the development stage of full electric units. Telematics on refrigeration equipment are becoming the norm rather than the nice to have, Swart notes. Customers and clients require this for temperature and product monitoring throughout the cold chain process. “The drive for connectivity is becoming important and we see companies investing vast amounts of money to improve and develop the technology. We find ourselves in a digital age and the refrigeration industry is doing their part in embracing technology available to assist with improving the cold chain and temperature control.

In South Africa we are not using telematics to improve the efficiency of the cold chain to its maximum, Heyman adds. “The rest of the world is ahead of us there and we need to catch up. Lower emissions and green energy are also advancing rapidly in the rest of the world and we must not be left behind.”
Internationally, many secondary distributors are investing in pure electrical drives for the cooling units. This is due to the emissions and noise pollution restrictions that are imposed on inner city deliveries, explains Heyman.

Electrification and the development thereof is becoming a real game changer internationally, notes Swart. There are some European countries not allowing any diesel engines anymore and enforcing zero diesel emissions. Manufacturers are thus forced to fast-track the development of electrification. “The next five to 10 years will be interesting, as the development of other power sources will bring about some challenging times and changes to what we know today.”

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