A refrigerated shipping container — a “reefer” — is a standard steel container with an integrated refrigeration unit and insulated walls, floor, and ceiling. It turns a shipping container into a walk-in cooler or freezer you can put anywhere you have power. Here's what to know before you buy one.

How a Reefer Is Built

The refrigeration machinery sits in one end wall, so a reefer's usable interior is shorter than a dry container of the same nominal length. The walls are insulated foam sandwiched between steel skins, and the floor is a T-shaped aluminium decking that lets cold air circulate underneath the cargo and back to the unit. That airflow design is why a reefer holds temperature far better than an insulated box with a domestic AC unit bolted on.

Temperature Range

Most integral reefer units hold a setpoint anywhere from roughly +77°F down to about -22°F (+25°C to -30°C), which covers chilled produce, dairy, floristry, pharmaceuticals, and hard-frozen storage. Deep-freeze and blast-chill duties are outside what a standard transport reefer is designed to do — if you need those, say so when you enquire and we'll tell you honestly whether a unit will get there.

Power Requirements — Check This First

This is where most reefer purchases go wrong. A standard integral reefer unit is built for three-phase power, typically in the 380–460V range, and it draws meaningfully more current on start-up than it does while running. A domestic single-phase supply will not run one.

  • Have three-phase on site? You need the right receptacle and a circuit rated for the unit — have an electrician confirm before delivery day.
  • No three-phase? A diesel generator set (genset) can power the unit, which is also how reefers run in transit. Budget for the genset, fuel, and servicing.
  • Smaller and converted units are sometimes built around single-phase equipment. Never assume — confirm the electrical spec for the specific unit you're buying.

Working vs. Non-Working Reefers

A working reefer has functioning machinery and is priced accordingly. A non-working reefer has the same insulated shell but a unit that no longer runs — and it's often the smarter buy. If you want a heavily insulated, wind- and watertight store for a workshop, a dry goods room, or a space you'll heat and cool your own way, a non-working reefer gives you all that insulation without paying for refrigeration you'll never switch on. We list working and non-working units separately and say which is which on the listing.

What to Check Before You Buy

  • Machinery hours and PTI: ask for the running hours and whether the unit has passed a pre-trip inspection (PTI), the standard self-test that exercises the whole refrigeration circuit.
  • Insulation integrity: punctures, crushed panels, or water-saturated foam quietly destroy efficiency. Look for bulged or soft wall panels.
  • Door gaskets: a reefer is only as good as its seal. Perished or flattened gaskets are cheap to replace but must be replaced.
  • Evaporator and condenser coils: heavy corrosion or bent fins mean reduced capacity and a repair bill.
  • Floor drains and T-decking: blocked drains and damaged decking break the airflow the design depends on.
  • Refrigerant type: older units may use refrigerants that are now costly or restricted to service.

Running Costs

A reefer is a piece of machinery, not just a box. Expect to budget for electricity (or diesel), periodic servicing of the refrigeration circuit, and eventual gasket and coil work. In exchange you get cold storage you own outright, on your own site, with no monthly rental.

Is a Reefer Right for You?

Buy a working reefer if you genuinely need controlled temperature and can supply the power. Buy a non-working one if what you actually want is the best-insulated container on the market. Not sure which? Talk to our team and describe the job — we'll point you at the right unit rather than the more expensive one. Browse refrigerated containers to see what's in stock.