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As demand has risen for smaller and smaller reefers, equipment manufacturers have risen to the challenge with a range of compact, light refrigeration units and insulation systems. Sharon Clancy reviews the latest developments.
ALone time reefers were invariably HGVs. There was an obvious need to keep a range of products at controlled temperatures for long-distance hai dage—but refrigerated vans were few and far between. Then the 1990 Food Safety Act required everyone involved in the food chain to demonstrate "due diligence" in ensuring that food remains fit for human consumption. That created a demand for lightweight reefers to handle jobs such as sandwich rounds to city-centre office blocks and supermarket home deliveries. As congestion increases, so does the appeal of small reefers. Bodybuilders and refrigeration unit manufacturers certainly think so, judging by their investment in new designs.
I Panel vans
Converting a car-derived or panel van for temperature-controlled work entails the use of wet-lay insulation or modular panels.
With the wet-lay method a timber frame and insulation are topped with a laminate surface. This is cheaper than fitting modular panels, but it has two main drawbacks: wet-laid insulation cannot be removed, and it is not as good at keeping out heat as modular insulated panels. Not only do the metal ribs that support the van side walls act as a thermal bridge, but the pockets of air that become trapped in the walls during conversion warm up as the ambient air temperature rises.
With a vacuum-pressed modu
lar panel there are no thermal bridges and all the air is removed.
An insulated vehicle's thermal efficiency is measured by the "K factor": the lower the K factor, the better the insulation. According to Alan Lines, managing director of Klege Europ, a wet-lay conversion is typically o.7K, compared with 0.3K or below for a modular conversion.
Modular panels can cost up to twice as much as a wet-lay conversion because each van model needs its own unique kit. But as well as enhanced performance these panels offer more consistent quality, and they can often be removed and reused on new chassis.
Panel construction varies. A stroair, for example, uses polyurethane foam with a skin of impact-resistant thermoplastic; Paneltex uses scratch-resistant Kemlite for interior surfaces_ It is also possible to use both options at once. For the RVL conversion on Convoy vans, for example, LDV has specified a combination of modular panels topped off with a wet-laid laminate to create a seam-free hygienic interior.
• Box bodies Box bodies can be moved between chassis, and they are easier to modify for different operations than insulated panel vans or CDVs.
RVL uses five-element panels bonded together. Other manufacturers such as Solomon use three-element panels reinforced with woven material and a combination of bonding and aluminium mechanical joints to increase resistance to knocks. Styrofoam is the most popular insulation, although polyurethane is also used A lot of the development work on insulated bodies for 3.5-tonners has been driven by the move by supermarkets into the home delivery market, led by frozen-food specialist Iceland. Panel vans were initially considered more acceptable for domestic deliveries, but they are being challenged by specially developed box bodies with multiple doors and cus. tomised racking systems to take supermarket crates, And 3.5-tonners are also competing with heavier reefers as operators demand better rn anoeuvrab i 1 i ty for urban deliveries. For its contract with Kerry Foods, Wincanton Logistics Contracts has moved from 7.5-tonners to 3.5-tonners for deliveries to small shops and garage forecourts.
There are now t75 Solomonbodied Mercedes-Benz Sprinter chassis in the fleet. As well as fixed shelves, the Kerry bodies have folding shelves to suit a wider variety of load shapes and sizes. Switches in the door operate the interior lights, just like your fridge at home, to stop vehicle batteries being drained.
Some operators choose panel van conversions over box bodies simply because delivery times can be quicker. GRP Group developed the Glacier 35 Series to combat this—it promises delivery in two to three weeks. There are chilled and frozen versions; GAH Javelin refrigeration systems and single rear door are fitted as standard.
• Refrigeration units Refrigeration units on small vehicles used to be pretty obtrusive; nowadays condensers are lowprofile or mounted under the bonnet. They can be inset into the roof profile on larger vans, or even underslung.
On the Diavia Frigosaft the condenser is mounted in the engine compartment, usually behind the radiator grille. Diavia says it is exploiting the expertise of its parent company, Delphi Automotive Systems, which manufactures more than 200,000 condensers every year, mainly for automotive air-conditioning systems. There are two Frigosoft models: the 1400W-capacity 2000 for car
derived vans, and the 3000 for larger vans.
The latest evaporators are much slimmer than their predecessors, minimising intrusion into the load space—this is a particular problem on small bodies.
The Mitsubishi 17 sold by John R Billows intrudes just 113 into the load space, for example, while the 25 model is available with an undermount condenser and dual evaporators. At 145mm the new evaporator on the Thermo King V-25o Plus is half the depth of the old unit, while the unit on the V-200 and V-o90 is even slimmer, at 130mm.
On Hubbard's innovative Split dual-temperature unit the problem of evaporator intrusion is solved by incorporating it in a plastic housing that forms part of the bulkhead. There are separate controls for each compartment.
There is no intrusion at all with the Kerstner unit sold by Astroair: it combines the evaporator and
condenser unit in one slim roofmounted unit just 220MM high.
The direct-drive refrigeration systems on small vehicles operate only when the engine is switched on, which means they can struggle to maintain box temperatures on stop-start work. Upgrading existing refrigeration units to give them more capacity is one solution. Carrier's Intregra 2oS is a higher-capacity version of its Zephyr and Basic units. producing 2,300W at o°C. It features a new slimline condenser which is
2 i4inm deep and 480rnm long. Thermo King's V-25o Plus produces 2,500W at o°C with R4o4a refrigeration; that's 12% more than the V-250.
Another solution is the eutectic beam refrigeration system, although this carries a weight penalty. Charged overnight from an external electricity supply, this system is silent, with the big capacity that is needed for multidrop work.
Cornish clotted cream producer Rodda makes up to 8o drops a day using its lveco Daily 3.5-toriner. Bodybuilder Reep fitted a Hubbard eutectic beam system on the front wall, behind a false bulkhead equipped with a i2,1/ fan. The bulkhead prevents the box temperature falling too far and spoiling the cream, while the fan speeds up delivery of cool air to the body.
CONTACTS
Astroair 01908 560822 Gamer Transicold 01925 611170 Mae 01256 842111 GAN 01394 386606 GRP Group . 01132 2554664
Hubbard ....... ,....,.... ,.01473 892289
di Billows (Mitsubishi) , „01536 310800
Klege Europ ........ 811441
Lamberet 01925 838055 Paneltex 01482 787236 Beep 01752 845225
Refrigerated Vehicles ....,.„01825 840733 Solomon COMPICialS ..... „...01706 211211 105 01202 718899
Thermo King 00-353 91 751231 TransfrOrouto 01572 722489