Chilled and frozen from one reefer: it's just a set point

Ask whether a refrigerated container is a chiller or a freezer and the honest answer is: it is both, from the same box. Cooling a tray of catering platters at +4 °C and holding ice cream rock-hard at -22 °C are not two machines but one machine on two settings. A reefer is built to sit anywhere between -25 °C and +25 °C, so the choice between chilled and frozen is a number you dial in, not a product you order. What genuinely changes when you drop from the chilled band to the frozen one is the electricity it draws, how you load it, and the food-safety rules you answer to. This page takes each in turn.

Chilled or frozen is a set point, not a product

The two bands people mean are straightforward. Chilled covers roughly 0 to +8 °C — prepared food, catering, drinks, dairy and fresh produce that must stay cold without freezing. Frozen runs -18 °C and below, as far as -25 °C for stock that wants the extra margin: frozen meat and fish, ready meals, and ice cream, which usually sits at the colder end of the range.

One standard container serves both. The same Carrier, Thermo King, Daikin or Star Cool refrigeration unit holds whatever set point you specify; there is no separate “freezer” machine on the hire market and no specialist premium for running cold rather than cool. That is why a chiller and a freezer container are priced off the same used and one-trip market. If you genuinely need lower than -25 °C — some pharmaceutical or seafood work does — that is the rare super-freezer territory of -60 to -70 °C, which costs more and is worth flagging up front.

Which goods sit at which band

One practical caveat: a single container holds one set point at a time. It cannot chill one shelf and freeze another, so a genuinely mixed load means either two units or accepting the whole box at one band. Decide the band before you decide the size.

What frozen duty costs to run

The real difference between the two bands is power. Pulling and holding a load at -18 °C makes the compressor work harder than keeping it at +2 °C, so frozen duty draws more electricity on the same size of container. Indicative daily consumption:

These are indicative figures. The unit draws 5 to 12 kW depending on size, on a three-phase 380/400 V supply through a 32 A CEE five-pin plug (some small formats run on 230 V single-phase). Electricity is billed on top of the hire rate at your own contracted unit price, so a frozen user should budget more for power than a chiller user of the same box. It is the line that most often catches people out, because the hire rate rarely includes it.

A reefer holds temperature — it does not blast-freeze

One consequence of the frozen band is worth stressing: a reefer is designed to maintain temperature, not to crash it down. Load product already at its target temperature and the unit holds it comfortably; load warm goods expecting the box to freeze them and you will wait, at some risk to the product on the way. Rapid freezing of warm stock is a different job — blast freezing, run on specialist equipment at temperatures well below a storage set point — not something a reefer is meant to do. For frozen storage the rule is simple: bring it in cold, keep it cold. The heavier the ambient heat outside, the harder a frozen set point works to hold, which is why the summer electricity figure sits at the top of the bracket.

Frozen storage and the rules

Two points on compliance, offered with care because they vary. ATP certification concerns refrigerated transport, not a container standing still on your yard; a statically sited unit is generally outside its scope, so do not assume ATP is required for storage. Food-hygiene duties such as HACCP, by contrast, may well apply to how you keep chilled and frozen stock, and the detail differs by activity and by local authority — treat any hard rule you read online as a prompt to check with the relevant body rather than as settled fact. The colder the band and the more sensitive the food, the more this is worth doing properly.

Choosing between the two — and comparing offers

In practice the goods make the decision for you: they set the band, the band sets the running cost, and the size sets the rest.

• Chilled catering, drinks or fresh produce → a reefer at 0 to +8 °C, lightest on power.
• Frozen stock, meat, fish or ice cream → the same container set to -18 °C or below, with a higher electricity budget.
• A permanent chilled or frozen need beyond roughly 18 to 24 months → buying starts to beat hiring; used units are observed at £4,500 to £7,500 ex VAT, new one-trip units at £18,995 to £22,500 ex VAT, with VAT at 20% on top. Our for-sale pages go through grades and checks.

Because one machine covers both bands, you are really choosing a size and a set point, then comparing suppliers on price and condition — where, at equal spec, the gap between offers stays wide. Browse the other comparisons for size and condition, or once your band and size are settled, request your quotes: we pass your request to specialist suppliers, who contact you directly if they can meet your requirement.