Used refrigerated containers, often referred to as reefers, are one of the most cost-effective ways for UK businesses to secure reliable cold or frozen storage. Originally built for international shipping, ex-marine refrigerated containers are designed to maintain precise temperatures in demanding environments and are now widely used for static storage, logistics, and export.
This guide explains how used refrigerated containers work, what “ex-marine” really means, the specifications you should expect, and how to choose the right unit for your application.
What Is a Refrigerated Shipping Container?
A refrigerated shipping container is a temperature-controlled ISO container fitted with an integrated refrigeration unit. Unlike standard containers, reefers actively regulate internal temperature rather than relying on ambient conditions.
Refrigerated containers are commonly used for storing or transporting:
- Frozen and chilled food
- Meat and seafood
- Dairy products
- Pharmaceuticals and medical supplies
- Flowers and agricultural produce
Most standard reefers operate within a temperature range of approximately -25°C to +25°C, depending on the refrigeration unit fitted.
What Does “Ex-Marine” Mean?
Reefer containers use a built-in refrigeration system powered by an external electrical supply. When used in trAn ex-marine refrigerated container is a unit that has been retired from active service by a shipping line or leasing company.
These containers:
- Are typically 10 to 15 years old
- Have been maintained to strict maritime standards
- Are built for continuous international operation
- Show cosmetic wear from shipping use
- Prioritise insulation, structure, and machinery over appearance
Cosmetic dents, surface rust, and shipping livery are normal. Structural integrity, insulation, and refrigeration performance are what matter.
Temperature Control and Performance
Most used refrigerated containers offer:
- Minimum set points around -25°C
- Maximum set points around +25°C
- Continuous temperature monitoring via thermostat
- Stable internal conditions regardless of external weather
This makes reefers suitable for frozen storage, chilled storage, or temperature-controlled ambient storage.
Shipping Certification and PTI Testing
Used ex-marine refrigerated containers supplied for export or operational use should include:
- Valid CSC certification, suitable for international shipping
- PTI testing confirming the refrigeration machinery is operational at dispatch
A PTI, or Pre-Trip Inspection, confirms that:
- The unit is capable of maintaining set temperatures
- The refrigeration unit has been checked by a qualified engineer
- No faults are present at the point of supply
Standard 20ft Used Refrigerated Container Specifications
Typical specifications include:
- Circuit breaker: D-rated motor breaker required
- External size: 20ft × 8ft × 8ft 6in
- Construction: COR-TEN steel shell
- Interior: Stainless steel or food-grade lining
- Floor: Aluminium T-bar flooring
- Condition: Used ex-marine
- Certification: CSC supplied
- Testing: PTI included
- Power: 32 Amp, 3-phase supply
Typical Uses for Used Refrigerated Containers
Used reefers are widely used across the UK for:
- Food and beverage storage
- Seafood and meat processing
- Pharmaceutical and medical storage
- Catering and event preparation
- Supermarkets and wholesalers
- Agricultural and rural cold storage
They are frequently used as walk-in fridges or freezers, offering significantly better value than purpose-built cold rooms when access is limited.
Used Refrigerated Containers vs Walk-In Cold Rooms
A used refrigerated container typically costs a fraction of a traditional walk-in freezer or cold room.
Key advantages include:
- Self-contained refrigeration system
- Portability and relocation flexibility
- Industrial durability
- Lower upfront cost
- Wide temperature range
For businesses that only access cold storage once or twice per day, reefers often provide superior value.
Condition and What to Expect
Used refrigerated containers are sold for performance, not appearance.
You should expect:
- Cosmetic dents and surface rust
- Shipping line branding
- Signs of international use
- Stiff doors that benefit from regular lubrication
All functional aspects are assessed before sale. Photos shown are representative only.
To understand lifespan expectations, see our guide on how long used refrigerated containers last.
Optional Extras and Conversions
Depending on your application, optional upgrades may include:
- Internal LED lighting
- Man-trap alarms for freezer use
- Thermal strip curtains
- Easy-open doors
- Flooring upgrades for forklifts
- Repainting for improved appearance
Because reefers are specialised equipment, discussing requirements before ordering is strongly recommended.
Delivery and Power Considerations
Before ordering a refrigerated container, ensure:
- Clear delivery access for a 20ft or 40ft unit
- Adequate offloading space
- A 3-phase 32 Amp power supply on site
- Sufficient ventilation around the refrigeration unit
If power availability or site access is uncertain, this should be checked in advance.
20ft vs 40ft Used Marine Refrigerated Containers
Choosing the right size depends on capacity, access, and budget.
- 20ft used ex-marine refrigerated containers are ideal for smaller sites, limited access, and lower power demand
View our 20ft used ex-marine refrigerated containers for sale - 40ft used high cube marine refrigerated containers offer greater internal height and significantly more storage volume
View our 40ft used high cube marine refrigerated containers
Both options deliver excellent cost-per-cubic-metre value compared to fixed cold storage.
Why Buy a Used Reefer from Bosh Boxes?
- Containers sourced from trusted shipping lines
- CSC supplied for export where required
- PTI testing included
- Honest advice on suitability and running costs
- UK-wide delivery available
- Practical guidance, not overselling
We focus on making sure a refrigerated container fits your application, not simply supplying equipment.
Bottom Line
If you need reliable, temperature-controlled storage or shipping capability, a used ex-marine refrigerated container offers outstanding value. With industrial durability, precise temperature control, and proven marine-grade construction, reefers remain one of the most versatile cold-storage solutions available in the UK.
For availability, specifications, and a tailored quote, contact Bosh Boxes today.
The Bosh Boxes Way.
