Reefer Container Specifications: Sizes, Temperature, Power

A 20ft reefer is 6,058 × 2,438 × 2,591 mm outside and about 5,460 × 2,292 × 2,310 mm inside. The 40ft high cube reefer is 12,192 × 2,438 × 2,896 mm outside, 11,580 × 2,290 × 2,400 mm inside. Internal length runs 450 to 600 mm short of a dry box because the integral unit fills the front bulkhead: a current unit measures about 2,235 × 2,025 × 415 mm. Today's 40ft reefer is the high cube reefer, ISO type 1AAA. The 2,591 mm 40ft is a legacy form. ISO 668:2020 fixes the envelope, so the reefer container sizes below differ inside, not outside.

The 20 ft high cube reefer container dimensions lift the ceiling to about 2,540 mm and the 40 high cube reefer container dimensions give 2,400 mm inside. Refrigerated container dimensions from any builder follow that pattern. Pallet-wide storage units, 2,500 mm wide for two Australian pallets at 35,000 kg gross, carry refrigerated shipping container dimensions of their own class.

A 20ft reefer weighs about 2,770 to 3,290 kg empty and a 40ft high cube 4,360 to 4,650 kg. Three maximum gross figures circulate. ISO 668:2020, as amended in 2022, rates the 1CC and 1AAA sizes at 36,000 kg. Fleet tables still print the older 30,480 kg. New-build plates on the AU market sit at 22,000 to 24,000 kg, set by the builder's CSC test. Reefer container weight for permits and pad design is the number on the CSC plate.

A standard integral reefer holds any set point from −30°C to +30°C in ambient temperatures from −30°C to +50°C. Humidity holds at 60 to 85% RH, or about 50% with dehumidification on newer units. ISO 1496-2:2018 sets the thermal tests: the sixth edition reinstated the −18°C / +38°C cooling-capacity test and added a 50°C ambient functionality test. The reefer container temperature range serves thresholds the food business owns, not the container. FSANZ Standard 3.2.2 keeps potentially hazardous food at 5°C or colder. A temperature controlled shipping container logs the evidence. The operator's HACCP plan carries the obligation.

Controlled atmosphere, super-freezer and blast options

Beyond the integral reefer specification, SCS builds:

• controlled-atmosphere units with managed O₂ and CO₂ for respiring produce
• super-freezer sets holding −60°C to −70°C
• a freezer shipping container with blast pull-down capacity
• twin-unit redundancy with a genset for high-value cargo
• remote monitoring

Blast-freezer depth sits on the reefer vs cold room comparison.

A reefer runs on 3-phase 380–460 V, 32 A, 50/60 Hz through a 5-pin reefer socket. It draws roughly 3 to 7 kWh per hour depending on size, set point and ambient. Your electrician installs the outlet to AS/NZS 3000:2018, and a genset carries the load in transit (how SCS ships containers to site). Reefer container power consumption moves with:

• ambient temperature and humidity
• insulation condition and unit age
• loading practice and door openings
• defrost cycles and pre-cooling

The unit draw and cooling figures in the table describe a current OEM unit (OEM datasheet); we fit whichever unit the buyer specifies.

A refrigerated shipping container works by blowing chilled supply air from the front-bulkhead unit under the cargo through an aluminium T-floor and drawing it back over the load. Air passes through the cargo continuously. A variable-speed reciprocating compressor, a condenser and an evaporator run the cycle. Fresh-air exchange runs from zero to 15–250 m³/h for respiring produce, against the ATP benchmark of 50 hourly air changes (RVTC Guide to ATP). A microprocessor controller logs supply and return air, defrost, set-point and power events. A current unit carries about 4.5 kg of R134a and runs R134a, R513A or R1234yf under ISO 20854:2019. We fit whichever reefer container refrigeration system the buyer specifies.

Reefer walls, roof and floor are foam-cored polyurethane sandwich panels with a stainless-steel interior and an aluminium T-section floor, built to minimise thermal bridging under the ISO 1496-2 heat-leakage test. ATP's heavily insulated class, K below 0.4 W/m²K, is the export benchmark only: Australia isn't an ATP party. Refrigerated container specifications for the shell follow the dry-box pattern: Corten end frames and rails with zinc metallisation, per Corten steel and container construction. Insulated double rear doors carry rivet-free gaskets and an internal emergency release on storage builds (OEM construction reference).

ISO 668 fixes the envelope and gross rating, ISO 1496-2 the thermal performance, the CSC plate the transport approval, and AS/NZS 3000 the site outlet. Compliance attaches to the body, the machinery, the site installation and the food business separately, so a reefer is never "HACCP certified" in itself. Every figure in these reefer container specifications traces to a document below, and CSC and ISO container standards carries the body depth. Stationary installations in Australia and New Zealand sit under AS/NZS 5149.3.

The Ozone Protection and Synthetic Greenhouse Gas Management Act 1989 requires an ARCtick Refrigerant Handling Licence to charge, service or decommission a unit, and an Equipment Licence to import an HFC-charged reefer. Australia's HFC import quota steps down from 8 Mt CO2-e in 2018 to an 85% cut by end-2035 (DCCEEW). Our factory-direct manufacturing covers the body build, and SCS project deployments show that discipline on delivered units.

What is a reefer container?

A reefer container is an ISO thermal container built to ISO 1496-2 with an integral refrigeration unit in the front bulkhead, holding a set point from −30°C to +30°C for transport or static storage. Standard sizes are 10ft, 20ft and 40ft high cube.

How are reefer containers powered?

Reefer containers run on shore power through a 32 A, 3-phase 380–460 V, 5-pin reefer socket. Single-phase 240 V units suit sites without 3-phase. Off-grid or in transit, a clip-on or underslung diesel genset at 15 to 25 kVA prime carries one unit.

How long does a reefer hold temperature when unplugged?

A loaded reefer holds chilled cargo for 2 to 4 hours before it passes 5°C, frozen cargo at −18°C for 4 to 8 hours and super-freezer cargo for 8 to 12 hours. Plan for no more than two hours off power. Beyond that, a genset.