If you’re looking for cold storage for your business, you’ve probably come across both refrigerated containers and blast freezers. They both keep things cold – so what’s the difference, and which one do you actually need?
The answer matters more than you might think. Choosing the wrong unit can damage your stock, put you on the wrong side of UK food safety law, and cost your business more money than necessary. This guide cuts through the confusion.
What Is a Refrigerated Container?
A refrigerated container – also called a reefer container – is a temperature-controlled storage unit with a built-in refrigeration system. Originally designed for international shipping, they’re now widely used across the UK for on-site cold storage by businesses of all sizes.
At Conrail, our refrigerated containers maintain temperatures from -40°C to +30°C, making them suitable for food retail, catering, pharmaceuticals, logistics, and much more. They connect to a standard or three-phase electricity supply, can be placed on any flat surface indoors or outdoors, and are available to hire short-term or purchase outright in 10ft, 20ft, and 40ft sizes.
The key thing to understand: a refrigerated container keeps goods at a target temperature. It is a storage solution.
What Is a Blast Freezer?
A blast freezer is a specialist unit designed to rapidly drop the core temperature of fresh, warm, or cooked goods – typically from around +50°C down to -18°C or lower within just a few hours. It does this using high-velocity fans that blast ultra-cold air (usually between -30°C and -40°C) across the product at high speed.
The key word is speed. Where a refrigerated container keeps things cold, a blast freezer gets things cold – fast.
The key thing to understand: a blast freezer changes a product’s temperature rapidly. It is a processing solution, not just a storage one.
The Critical Difference: Storage vs Freezing
This is where most businesses get confused, so it’s worth being clear:
A refrigerated container stores goods that are already at the right temperature. A blast freezer is used to rapidly freeze warm or fresh goods before they go into storage.
Think of a refrigerated container as a very large, very reliable fridge or freezer. Think of a blast freezer as the process that gets food freezer-ready in the first place.
If you receive fresh fish and need to freeze it quickly to preserve quality and meet food safety requirements, you need a blast freezer. Once frozen, you then transfer the stock to a refrigerated container for ongoing storage. Many food processing businesses in the UK use both – and we’ll come back to that.
Side-by-Side Comparison
| Feature | Refrigerated Container | Blast Freezer |
|---|---|---|
| Temperature Range | -40°C to +30°C | -30°C to -40°C |
| Primary Function | Maintain steady temperature for storage | Rapidly freeze warm or fresh goods |
| Cooling Speed | Steady and gradual | Fast – hours, not days |
| Power Usage | Moderate | High |
| Best For | Storing already-chilled or frozen goods | Freezing fresh produce, cooked food, meat, fish |
| Typical Users | Retailers, caterers, pharma, events | Meat processors, fisheries, ready meal producers |
| Hire Cost | Lower | Higher |
| UK Availability | Widely available | Available – specialist providers |
Why Freezing Speed Matters
This is something many businesses overlook. The speed at which food is frozen has a direct impact on product quality.
When food freezes slowly – as it would in a standard refrigerated container set to a low temperature – large ice crystals form inside the cellular structure of the product. These crystals rupture cell walls, leading to loss of texture, nutrient degradation, reduced shelf life after thawing, and poorer taste and appearance.
A blast freezer freezes product so quickly that only tiny ice crystals form. The cellular structure stays intact. The result is food that thaws almost indistinguishably from fresh – which is why blast freezing is the gold standard in commercial food production.
For businesses where product quality is critical – premium ready meals, high-end catering, seafood processors, artisan bakeries – a blast freezer isn’t a luxury. It’s essential.
Which Industries Need a Blast Freezer?
Blast freezers are best suited to businesses that process fresh or cooked goods and need to freeze them quickly before storage or distribution:
- Meat processors and abattoirs – freshly processed product must be chilled rapidly to comply with food hygiene regulations
- Seafood and fisheries – fish deteriorates faster than almost any food; blast freezing immediately after catch preserves maximum quality
- Ready meal manufacturers – cooked products must be chilled below 8°C within 90 minutes under UK food safety law
- Artisan and industrial bakeries – blast chilling preserves crust, texture, and moisture
- Fruit and vegetable producers – rapid cooling halts the enzymatic activity that causes ripening and spoilage
- Pharmaceutical manufacturers – some biologics and temperature-sensitive compounds require controlled rapid cooling
Which Industries Need a Refrigerated Container?
Refrigerated containers are the right choice when you need reliable, consistent cold storage for goods that are already at temperature:
- Food retailers and supermarkets – overflow chilled or frozen stock during busy periods
- Restaurants and catering companies – on-site cold storage for ingredients and prepared food
- Event organisers and festival caterers – temporary refrigeration at venues with no fixed cold storage
- Pharmaceutical distributors – vaccines, medications, and biologics stored at a steady +2°C to +8°C
- Logistics and distribution businesses – buffer storage in cold chain supply chains
- Breweries and distilleries – temperature-controlled conditioning and storage
- Retail chains – extra capacity during Christmas, summer, and other seasonal peaks
Quick Decision Guide
| Your Situation | Right Solution |
|---|---|
| You need to store goods that are already chilled or frozen | ✅ Refrigerated Container |
| You receive fresh meat, fish, or produce that needs freezing on-site | ✅ Blast Freezer |
| You need flexible cold storage for an event or seasonal peak | ✅ Refrigerated Container |
| You run a food processing facility and freeze large batches daily | ✅ Blast Freezer |
| You need pharmaceutical storage at a steady controlled temperature | ✅ Refrigerated Container |
| You want to extend shelf life of fresh-cooked meals or baked goods | ✅ Blast Freezer |
| You need cost-effective general cold storage for your supply chain | ✅ Refrigerated Container |
| You produce ready meals and need rapid chill-down to meet food safety rules | ✅ Blast Freezer |
Can You Use Both Together?
Yes – and for many food businesses, using both is the optimal setup.
A common and highly effective approach used by UK food processors and distributors is:
- Receive fresh or cooked goods at ambient or warm temperature
- Blast freeze immediately to bring the core temperature below -18°C within hours
- Transfer to a refrigerated container for ongoing frozen storage until dispatch
This two-stage process preserves maximum product quality while keeping stored goods at a safe, stable temperature. It also helps businesses meet UK food safety requirements around rapid cool-down of hot food. At Conrail, we can advise on the best combination of units for your operation.
Food Safety and Compliance: What UK Law Requires
UK food safety legislation has specific requirements around temperature control that directly affect which type of cold storage you need.
The Food Safety and Hygiene (England) Regulations 2013 require that hot food intended for cold storage must be cooled as quickly as possible. For businesses producing cooked or ready-to-eat food, this typically means blast chilling is not just preferable – it may be a legal requirement.
A standard refrigerated container cannot achieve the rapid cool-down that cooked food requires. A blast freezer or blast chiller is the compliant solution in these cases.
For businesses storing chilled products – fresh produce, dairy, or pharmaceuticals at +2°C to +8°C – a refrigerated container is perfectly suitable and fully compliant.
How Much Does It Cost?
Hiring is the most practical and cost-effective approach for most UK businesses, particularly where cold storage needs are seasonal, temporary, or unpredictable.
Refrigerated containers are generally more affordable to hire than blast freezers, which carry higher running costs due to their power-intensive fans and compressors. Both are available on flexible terms – from a few weeks to long-term arrangements. If you use a blast freezer year-round, purchasing outright may be worth considering.
At Conrail, We also offer purchase options with buyout discounts for long-term customers.
Why Choose Conrail for Cold Storage in the UK?
Conrail has been supplying refrigerated containers for hire and sale to UK businesses since 2009. Our units are manufactured to the highest specifications and we offer:
- Refrigerated containers for hire and sale in 10ft, 20ft, and 40ft sizes
- Temperature ranges from -40°C to +30°C
- UK-wide delivery and rapid deployment
- 24/7 technical support throughout your hire period
- Flexible short and long-term hire terms
- Full maintenance cover on all hire agreements
- Purchase options with buyout discounts
Frequently Asked Questions
Can a refrigerated container be used as a blast freezer?
No. A refrigerated container is designed to maintain a steady temperature, not to rapidly reduce the temperature of warm goods. Blast freezers use powerful compressors and high-velocity fans engineered specifically for rapid temperature reduction. Using a refrigerated container as a blast freezer will result in slow freezing, large ice crystal damage, and potential food safety non-compliance.
What temperature does a blast freezer reach?
A blast freezer typically operates at between -30°C and -40°C during the freezing cycle. This extreme cold, combined with high-velocity airflow, brings product core temperature down to -18°C or below within 2–6 hours.
What is the difference between blast freezing and blast chilling?
Blast chilling reduces food to around +3°C (chilled, not frozen), while blast freezing takes it to -18°C or lower. Both use rapid cold airflow but to different temperature endpoints. Food safety applications for cooked food typically use blast chilling; long-term frozen storage requires blast freezing followed by transfer to a refrigerated container.
Can I hire a refrigerated container for just one week?
Yes – Conrail offers flexible hire terms to suit short-term requirements, whether you need a unit for a single event, a few weeks during a seasonal peak, or on an ongoing basis.
How do I know what size refrigerated container I need?
The most common sizes are 20ft (holds approximately 6 pallets) and 40ft (holds approximately 12–14 pallets). Our team at Conrail can advise on the right size based on your stock volume and site layout.
Need a refrigerated container for hire or sale? Conrail delivers UK-wide with flexible terms and 24/7 support. Visit conrail.co.uk or get in touch for a quote.