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A reefer is a refrigerated trailer or truck: an insulated box with its own refrigeration unit that holds cargo at a set temperature, from frozen at 0°F or below to cool but above freezing. Shippers of produce, meat, dairy, frozen food and some medicines need reefers. Carriers run them because the freight moves all year and pays more per mile than dry van.
What a reefer is made of
Strip a reefer down and you get three parts. First, an insulated box: thicker walls, floor and roof than a dry van, with sealed doors. Second, a refrigeration unit, mounted on the front wall of a trailer or above the cab of a straight truck, with its own diesel engine or an electric motor. Third, a controller that reads air temperatures inside the box, runs the unit to hold the setpointTRUCKING TERMThe temperature the reefer unit is set to hold, written by the shipper on the bill of lading. and records what happened on the trip.
The air moves in a loop. Cold supply airTRUCKING TERMSupply air is the air leaving the reefer unit into the trailer. Return air is the air coming back to the unit after passing over the load. leaves the unit along the ceiling, travels to the rear doors, drops through and around the pallets and returns along the grooved duct floor to the unit. Block that path with pallets jammed against the front wall or loaded to the roof and the back of the load warms up even when the display reads fine. Use the graphic above to see where each part sits.
The unit is built to hold cold product cold. It isn't built to cool warm product quickly. Perishables should already be at or very near their carrying temperature when loaded; the trailer should be precooled.
Source: UF/IFAS HS1328, Protecting Perishable Foods During Transport by Truck or Rail (Brecht et al.), revision of USDA Agriculture Handbook 669, October 2026
Types of reefers
Reefer equipment comes in four main shapes. Each fits a different kind of freight and route.
| Type | What it is | Typical work |
|---|---|---|
| 53 ft reefer trailer | Single-temperature trailer pulled by a semi tractor | Full truckloads of produce, meat, dairy and frozen food over the road |
| Multi-temp trailer | Reefer trailer split into compartments held at different temperatures | Grocery and food service loads mixing frozen and chilled product |
| 26 ft reefer box truck | Straight truck with a refrigerated box, non-CDL up to 26,000 lb GVWR or CDL above | Regional multi-stop routes, partial loads, deliveries to stores and restaurants |
| Reefer container | Refrigerated shipping container on a chassis, often with its own plug-in unit | Moves between ports, rail ramps and cold storage |
The multi-temp trailerTRUCKING TERMA reefer trailer with separate compartments that can be held at different temperatures on the same trip. earns its higher price on routes where one stop takes ice cream and the next takes lettuce. The 26 ft reefer box is the smallest truck we dispatch; we don't dispatch smaller box trucks, cargo vans or sprinters. Container work is its own trade, covered in our guide to reefer drayage. For the tractor and box side of the equipment, read reefer trucks explained.
What reefers carry
Anything that spoils, melts, freezes or loses value outside a temperature range. The temperature is set by the product, and the shipper writes it on the bill of lading. A few lowest safe carrying temperatures from the university transport handbook show how wide the range is:
- Frozen food: Frozen foods: 0°F (-18°C) or below.
- Tablestock potatoes: 38°F (3.3°C) for tablestock.
- Hass avocados: 40°F (4.4°C) for Hass and other cold-tolerant types.
- Bananas and tomatoes: 55°F (12.8°C). Colder than that damages them.
Source: UF/IFAS HS1328, Protecting Perishable Foods During Transport by Truck or Rail (Brecht et al.), revision of USDA Agriculture Handbook 669, October 2026
Those are reference points, not instructions. The setpoint on the bill of lading is the one that counts. Mode matters too: continuous run mode for fresh produce, chilled meat and other temperature-sensitive cargo; start-stop mode should not be used for fresh produce. Frozen loads often run start-stop to save fuel.
The frozen and chilledTRUCKING TERMFrozen freight is carried at or below 0°F. Chilled freight is kept cold but above freezing, at the setpoint the shipper writes on the bill of lading. sides of the business behave differently. Produce follows the harvest, so volume and rates shift between growing regions through the year. Meat, dairy, frozen food and pharmaceuticals ship all year, which is what keeps a reefer busy between seasons. Food loads also come with sanitation rules. Under FDA's Sanitary Transportation rule, carriers must pre-cool refrigerated compartments when the shipper specifies it, and must be able to show the operating temperature was kept during transport when the shipper or receiver asks.
Source: FDA, FSMA Final Rule on Sanitary Transportation of Human and Animal Food (21 CFR Part 1, Subpart O), October 2026
What a reefer costs to buy and run
A reefer costs more than a dry van at every stage. Here are the numbers we could source, with their dates.
Buying the equipment
53 ft reefer trailer with unit: $75K to $110K new, $25K to $65K used. The refrigeration unit is roughly $15K to $35K on a straight truck and more on a trailer; multi-temperature and electric-standby units cost more. On a used trailer, the hours on the unit tell you more than the trailer's age. A unit with high reefer hoursTRUCKING TERMThe hours a reefer unit's engine has run, used to plan maintenance and track unit fuel. may need an overhaul soon after you buy it.
Source: Bay Street Lending, refrigerated truck financing price ranges (October 2026 update), October 2026
Space inside
Insulation takes room. 53 ft reefer trailer: inside height 103 in., inside width 96 in., duct floor, single-temperature unit with electric standby (Penske's most commonly rented reefer; specs vary by make, model and year). A dry van of the same length is a few inches wider and taller inside, which matters on high-cube freight. Read the full spec on the trailer you're buying or leasing.
Source: Penske Truck Leasing, 53 ft refrigerated trailer specifications, October 2026
Running it
The unit burns its own fuel on every hour it runs, including the hours you wait at a shed. Diesel averaged $6.38 a gallon in late September 2026, against $3.75 a year earlier, so unit fuel now eats far more of a load than it did. Mode changes the bill: switching a reefer unit from continuous to start-stop mode can cut run time and fuel use by about 40%. Estimate a trip with our reefer fuel burn calculator.
Source: U.S. EIA, U.S. On-Highway No. 2 Diesel retail price, weekly average, late September 2026, October 2026
Add washouts before food loads, unit service, the download and the higher cargo coverage many reefer shippers require, and the per-mile cost of a reefer sits well above a dry van's. For the whole fleet picture, ATRI put the average cost of running a truck at $2.336 per mile in 2025, the highest in the report's history and 3.4% above 2024.
Source: ATRI, An Analysis of the Operational Costs of Trucking (2026 update, 2025 data), as reported by Transport Topics, July 17, 2026; data from for-hire fleets, October 2026
What it means for the loads you can haul
A reefer opens two markets at once. You can haul temperature freight, and with the unit off you can haul most dry freight too. That flexibility is the main reason carriers pay the higher price.
The pay reflects the extra cost. In the week ending September 25, 2026, DAT's national reefer spot linehaul average was $2.71 per mile, against $2.17 per mile for dry van. That gap only turns into profit if the unit fuel, washouts and waiting are paid for too.
Source: DAT Reefer Report, national average spot linehaul (excludes fuel), week ending September 25, 2026, October 2026
Waiting is where reefer money leaks. The trucking industry standard is that a driver should be loaded or unloaded and back on the road within 2 hours of arriving at a facility. Produce sheds and cold storage docks often run past that, and your unit burns fuel the whole time. Before you say yes to a reefer load, know these five things:
- The setpoint and mode, written on the bill of lading.
- The pulp temperatureTRUCKING TERMPulp temperature is the temperature inside the product itself, measured with a probe, not the air in the trailer. range you can accept at pickup.
- Pickup and delivery appointments that fit your hours.
- Detention after the free time, and who pays the lumper.
- Whether the shipper wants a washout certificate.
Source: USDOT Office of Inspector General, report ST2018019 (2018), October 2026
The carrier runs the unit and owns the cargo claim, so records protect you: pulp readings at pickup, photos, and the reefer downloadTRUCKING TERMThe record pulled from a reefer unit's controller showing setpoint, temperatures and events over a trip. It's key evidence in a temperature claim. after delivery. Drivers who keep them settle rejections quickly. If you're hiring for the seat, our guide to the reefer driver job covers what the work asks of a driver.
Once the unit is cold, the next problem is keeping it loaded, ideally with a reload close to the delivery instead of a long empty run back to the produce. That's the work our reefer dispatch desk does. We find and negotiate the load, check the setpoint, mode, pulp range, appointments, detention and lumper terms, and send you the full offer. Nothing is booked until you say yes, and the broker sends the rate confirmation straight to you. The fee is 5% of gross for one truck with authority older than 6 months, charged only on loads you haul. For how a dispatcher works a reefer load step by step, read our reefer dispatch guide.