What is a refrigerated van: the equipment, the vehicle and how it all works
The word 'refrigerator' is used for two different things, and the confusion starts right in the search bar. Some people are looking for refrigeration equipment — the unit fitted to a van body (also called a refrigeration/heating unit). Others are looking for a complete refrigerated van — a truck with an insulated body and cooling, ready to carry food. In this article we cover both meanings: how the unit is built, what the temperature ranges are, what happens to the refrigerant inside the circuit — and why the body matters no less than the 'fridge' itself.
The refrigerated van as a vehicle
A refrigerated van (also known as a reefer, a refrigerated truck, a thermal van with a refrigeration unit, a 'fridge on wheels') is a goods vehicle with an isothermal van body and a refrigeration unit that carries cargo at a set temperature: from vegetables and dairy products to deep-frozen goods and ice cream.
The main temperature modes:
- chilling 0…+5 °C — dairy products, chilled meat, vegetables, fruit, flowers, confectionery;
- universal −5…+5 °C — mixed runs, semi-finished products;
- freezing −18…−20 °C — meat, fish, frozen semi-finished products;
- deep freezing down to −24 °C and below — ice cream, blast-frozen berries (we have built bodies rated for −35 °C too);
- multi-temperature — a partition divides the body into chambers at different temperatures, for example −18 °C and +5 °C at the same time;
- +heating in winter — refrigeration/heating units keep the body above zero in frost: bread, drinks, cosmetics, medicines.
How a refrigeration unit works: the diagram
All transport refrigeration is one and the same closed cycle. The unit does not 'produce cold' — it moves heat from inside the body to the outside.
Step by step:
- The compressor compresses the refrigerant vapour — pressure and temperature rise sharply.
- The condenser (the external radiator) is blown by a fan: the hot gas gives up its heat to the outside air and condenses into a liquid. This is where the heat is 'dumped outside'.
- The TXV — thermostatic expansion valve — is a narrow nozzle between the high- and low-pressure sides. Liquid refrigerant is sprayed through it into the evaporator.
- The evaporator inside the body: the pressure downstream of the TXV is low, so the atomised refrigerant boils instantly at just −25…−40 °C. The boiling liquid draws heat from the air in the body — fans push this air through the evaporator coil and distribute the chilled flow along the ceiling. That is how convection works: cold air sinks through the cargo, picks up heat and returns to the evaporator.
- The vapour with the 'collected' heat goes back to the compressor — and the cycle repeats.
The physics is simple: a liquid boils and absorbs heat where the pressure is low (inside the body), and condenses and releases heat where the pressure is high (outside). The compressor and the TXV create that pressure difference.
The compressor — the heart of the unit
Transport refrigeration most often uses an open-type piston compressor with a belt drive from the vehicle's engine and an electromagnetic clutch. The clutch couples the pulley to the shaft when the thermostat calls for cooling and releases it once the set point is reached. Inside are pistons, a swash plate, a valve plate and a pressure-relief valve. Oil is critical: its type and quantity are specified by the unit manufacturer, and running short of it kills a compressor faster than anything else.
We have covered this in detail in separate articles: compressor design and faults, plus pages on specific models — TM13, TM16, Sanden SD7H15, SD5H14 and SD5H11.
What types of refrigeration equipment there are
- Engine-driven units — the compressor is belt-driven by the vehicle's engine. Simple and inexpensive; you have cooling while the engine is running. Examples — Elinge, Carrier, Kaida.
- Units with a 220/380 V electric supply (stand-by) — when parked, the unit plugs into the warehouse mains: the engine is off, yet the body holds its set point all night. Saves fuel and engine life.
- Self-powered units — with their own diesel engine. Independent of the chassis engine; used on medium and large trucks and on intercity routes.
- Eutectic plates — 'cold accumulators': plates filled with a solution freeze overnight from the mains and release cold during the day without a running compressor. Ideal for ice-cream delivery — see our eutectic plate manufacturing.
- Heating equipment — a refrigeration/heating unit with a heat pump, or a heater: in a Kazakh winter the cargo needs heating, not cooling.
Why the body matters as much as the unit
A refrigerated body has to meet three strict requirements:
- Hygiene — the interior surfaces must be easy to wash and must not absorb odours or grease: food transport is sanitised regularly.
- Air-tightness — any gap is a 'hole' through which heat is sucked in while the cold and your money leak out. Door seals and intact joints are what count.
- Low thermal conductivity — the wall must let through as little heat as possible, with no thermal bridges through a metal frame.
That is exactly why we at COND started manufacturing our own bodies: so that the unit's operating conditions match its capabilities instead of fighting against it. Our panels are a frameless sandwich: two layers of coated metal with extruded polystyrene (XPS) between them, 50–100 mm thick. With no through metal ties, the wall's thermal conductivity is below 0.4 W/(m·°C).
▶Materials chosen for long service life:
- stainless steel in the rear portal — the hardest-working loading zone: it does not rust from impacts or washing;
- galvanised and stainless hardware — locks, hinges and latches do not corrode;
- fibreglass on the rear doors — lighter than metal, does not rot, withstands impacts;
- anodised aluminium profile along the body edges — protecting the corners and sealing the joints.
The Kazakhstan factor: heat is the toughest exam
The unit and the body should be selected for the real climate, not the brochure. Summer in Kazakhstan means a steady +35…+40 °C in the south: Kyzylorda, Shymkent, Taraz, the Turkistan and Zhambyl regions. July 2026 showed what our weather can do: forecasters predicted heat of up to +45 °C, +43 °C was recorded in the south and +40 °C in Shymkent (feeling like +44 °C), while back in May temperature records that had stood for 80 years were broken.
What this means in practice: at +42 °C outside and −20 °C inside, the temperature difference across the wall is 62 degrees. Every extra tenth of thermal conductivity and every gap translates into hours of compressor running time, litres of fuel and the risk of the cargo defrosting in a traffic jam. That is why for southern routes we always size the unit with a heat-gain margin and recommend a thicker panel.
An important limit: every refrigeration unit manufacturer specifies a maximum ambient temperature up to which the unit is guaranteed to operate (typically around +40…+50 °C per the specific model’s datasheet). Run the unit beyond that limit and the condenser can no longer reject heat, circuit pressure climbs — and the unit fails; this is not a warranty case. That is why the rated ambient range is the first question when selecting a unit for southern Kazakhstan. We are preparing a separate in-depth article on these limits by manufacturer.
Frequently asked questions
Are a refrigerated van and an isothermal van the same thing?
No. An isothermal van is only an insulated body: it slows warming down but does not cool. A refrigerated van = an isothermal body + a refrigeration unit.
What is a refrigeration/heating unit?
A unit that cools the body in summer and heats it in winter. We install and service them: refrigeration equipment installation.
Can an ordinary van be converted into a refrigerated van?
Yes: we insulate the body, fit a unit and register the changes. Read more — van insulation and the vehicle-passport entry.
Which unit is needed for −18 °C?
It depends on the body volume, panel thickness and climate. We do the heat-gain calculation free of charge — see how to choose a refrigerated van or request a calculation.
The bottom line. A refrigerated van is a system: the right unit + an airtight body with low thermal conductivity + honest installation. We do all three ourselves — COND refrigerated vans are built in Almaty from 14 days, and we work across the whole of Kazakhstan.