The figures we use
These hourly consumption figures are those observed on the market, at normal load and mild outside temperatures. They also form the basis of our electricity consumption guide.
| Size | Chilled (+2 °C) | Frozen (-18 °C) |
|---|---|---|
| 10ft (~15 m³) | 2–3 kWh/h | 2.5–3.5 kWh/h |
| 20ft (~28 m³) | 3.5–4 kWh/h | 4–4.5 kWh/h |
| 40ft high cube (~67 m³) | 7–8 kWh/h | 8–9 kWh/h |
Electricity isn't the only cost
When buying, you also need to add delivery by crane lorry (£800 to £2,000 depending on distance and access), the electrical connection if one isn't already in place, and the annual servicing of the refrigeration unit. Our price guide covers the full budget, and our hire or buy comparison works out the threshold above which buying becomes the more sensible choice.
Frequently asked questions
Does this calculator give me my exact bill?
No, and no tool can. It applies typical hourly consumption figures to your kWh rate. Actual consumption depends on the outside temperature, how often the doors are opened, the condition of the seals, the goods stored and the age of the refrigeration unit. A ballpark figure for budgeting, not a quote.
Why does frozen mode use more?
Because the gap between the set temperature and the outside temperature is larger: holding -20 °C when it's 30 °C outside means removing far more heat than +2 °C, with more frequent defrost cycles. On a 20-foot unit, that's roughly £2 to £4 a day of difference.
How can I reduce consumption?
Limit door openings, check the seals (the main cause of heat loss on used units), place the container in the shade, leave space around the refrigeration unit, and don't set the temperature lower than necessary: every degree costs money.
What electrical supply do I need?
From 5 to 12 kW depending on size, three-phase 380/400 V with a 32 A CEE plug. The compressor start-up draws more current than steady running: allow some headroom and have the installation checked by an electrician.