Most businesses looking for a refrigerated vehicle are not looking for the vehicle. They want one outcome: the goods arrive at the same temperature they left the depot. A reefer is one way of getting there. Once the route moves into the city, the load drops to a pallet or two and the door opens twenty times a day, the shape of the problem changes and the answer has to change with it.
What a reefer actually cools
In a refrigerated vehicle what gets cooled is the air in the body, and the unit cooling that air depends on the vehicle running. The Turkish Ministry of Education's vocational module sets out the arrangement plainly: on bodies of 5 to 13.60 metres the compressor is driven by the unit's own diesel engine, while on bodies up to 5 metres it usually takes its drive from the vehicle engine's crank pulley through a V-belt.
Opening the door undoes that arrangement. In the same module's words, the moment the door opens the cold air runs downwards and warm air takes its place. On a forced-air body, the time the door stays open shows up in three lines: fuel and energy burnt for nothing, the evaporator fan throwing cooled air out of the body, and as much warm, humid air coming in as went out.
On a trunk run those three lines happen a few times per trip. On urban distribution they happen at every stop. That is where the economics of a reefer come apart: the unit runs, fuel burns, the door is open and the cooled air goes into the street.
Where the cold sits: body air or closed container
The second route takes the cold source off the vehicle and puts it beside the goods. An insulated container is a closed box: frozen eutectic plates go inside it and, depending on the plate regime, hold a chilled or a frozen load. The vehicle stays standard and nothing is fitted to the body.
The energy is spent at the depot, not on the route. Plates freeze overnight on a freezing rack on mains power, go into the container in the morning and ask for nothing more for the rest of the round. The vehicle door may open twenty times; the container lid stays shut and the cold stays with the goods.
The regime is separated per container, too. Two containers prepared with different plate regimes travel in one vehicle: one chilled, one frozen. Dry goods ride in the rest of the body. Three temperatures on one route, in one vehicle.
In exchange it asks for discipline. The container has to be pre-cooled, goods loaded at the right temperature, the lid kept shut between stops and the delivery order set so the container is not opened for nothing. There is no correcting it on the road; the round is won at the depot.
Which one wins which job
| Situation | Refrigerated vehicle | Insulated container plus eutectic plates |
|---|---|---|
| Long distance, full load, few stops | Strong | Regime hours limit the length of the round |
| Urban round, 10-30 stops | Loses cold at every opening | Lid stays shut; loss does not track the number of stops |
| One to three pallets, partial load | Cooling runs for the whole body | Only the loaded container is cooled |
| Different temperatures on one route | Needs a multi-compartment body | Two containers, two regimes, one vehicle |
| Vehicle in service or broken down | Load is left without cooling | Container moves to another vehicle |
| Seasonal peak in capacity | Extra vehicle or rental | Grows by the number of containers |
| Switching to electric vehicles | Refrigeration eats into range | Draws no energy from the vehicle |
| Night delivery | Unit noise | Silent |
There is no one-sided row in that table: the reefer wins the first one, and leaving that out would take the credibility of every other row with it.
What to work out for your own route
The figure comes out of your operation. The lines that make the comparison mean something:
- hours the unit runs per round and the fuel burnt in those hours
- scheduled servicing, and the deliveries that stop on the days the vehicle is in the workshop
- internal volume and payload given up to the unit and the insulation
- whether a vehicle committed to refrigeration can go back to dry work
- noise limits on night and early-morning delivery
- how many months a year the peak-season capacity stands idle
Put those lines side by side for your own route and the decision settles itself. Send us the route, the daily volume and the target temperature and we will work the numbers through with you.
How it is set up with Isotec
The programme runs on the GEBHARDT Isotec TBX: nine sizes from 410 to 1500 litres, 500-700 kg payload, regimes of 0…+2 °C and -21…-25 °C, ATP and HACCP certified for food transport. The 24 hour ceiling quoted above is the figure given for these containers.
Alongside the container: freezing racks that take plates down to the core, rails that hold the plate under the ceiling, and EPP thermoboxes for the last few metres. Size and plate regime follow the route, the volume and the target temperature; send those three facts and we propose the right one of the nine sizes.
The record side
For frozen goods the Turkish Food Codex sets the figure at -18 °C or lower at every point, and a brief rise of no more than 3 °C is allowed only in transport, distribution and the retail cabinet - it is not a storage tolerance. Recording ambient temperature with date and time during carriage, and keeping those records, is the requirement of a separate communiqué.
The record does not care which technology you run: container or reefer, it goes into the same file. The set value and the air reading do not replace the product measurement taken at goods-in.
