A cold store is a storage space actively refrigerated to keep goods in optimum conditions. Technically, cold storage classification is assessed against 5 core criteria: operating temperature, purpose, storage capacity, construction type and refrigerant. Understanding these criteria helps a business grasp the technical differences and choose the right type of store for its product and its scale, optimising the capital cost. With more than 20 years building industrial refrigeration systems in Vietnam, Tan Long offers the most practical perspective to help investors make the right decision.
What is a cold store, and why classify them?
A cold store is a storage space fitted with an active refrigeration system, holding a stable temperature anywhere from 10°C (50°F) down to −86°C (−123°F) to preserve food, pharmaceuticals and sensitive goods. Classifying them correctly helps a business select the right equipment configuration, refrigerant and insulated panel, minimising product losses and saving on running costs.
How does a cold store differ from a chill room? A chill room mainly holds temperatures above zero, while “cold store” covers the deep sub-zero ranges used for freezing and long-term frozen storage. Why does each product need its own temperature range? Every type of biological cell and molecular structure reacts quite differently to temperature, so holding the correct temperature prevents bacterial growth and keeps nutrients intact.
Classifying cold stores by operating temperature
By operating temperature, cold stores fall into four main groups: cool storage (0°C to 10°C), freezer (−18°C to −25°C), rapid blast freezers (−35°C to −45°C), and ultra-low temperature stores (−60°C to −86°C). The temperature range directly determines the type of compressor, the refrigerant technology and the panel thickness required.
| Warehouse type | Temperature range | Typical products | Recommended panel thickness |
| Cool storage | 0°C to 10°C (32°F to 50°F) | Fruit and vegetables, dairy, cut flowers, pharmaceuticals | 75-100 mm |
| Cold storage | −18°C to −25°C (−0.4°F to −13°F) | Meat, frozen seafood, ice cream | 125-150 mm |
| Freezer | −35°C to −45°C (−31°F to −49°F) | Tuna, shrimp and fresh seafood for rapid freezing | 150-200 mm |
| Ultra-low temperature store (ULT) | −60°C to −86°C (−76°F to −123°F) | Vaccines, biological samples, pharmaceutical products | 200 mm and above |
Chill rooms (chiller, 0°C to 10°C)
A chill room holds a temperature above zero, between 0°C and 10°C (32°F to 50°F), and is used mainly for fruit and vegetables, dairy, cut flowers and certain pharmaceuticals. What humidity does a chill room hold to stop vegetables wilting? The optimum humidity for this type of store is normally 85–95%, to prevent surface moisture loss from the produce. At the design stage, the industrial evaporators are carefully sized to maintain the optimum temperature differential.
Freezer stores (freezer, −18°C to −25°C)
A freezer store operates between −18°C and −25°C (−0.4°F to −13°F), for long-term storage of meat, frozen seafood and ice cream. Standard practice for storing food of animal origin requires a minimum of −18°C (−0.4°F) to completely suppress the growth of harmful micro-organisms. As a technical principle, the frozen storage temperature must always be at or below the product's core temperature after freezing.
Blast freezers (−35°C to −45°C)
A blast freezer produces an extremely low range of −35°C to −45°C (−31°F to −49°F), focused on chilling product rapidly to preserve the cell structure of shrimp, tuna and fresh seafood. The biggest difference with this type of store is the very high rate of surface heat exchange. At the Kyokuyo Vina Foods project, Tân Long designed a blast freezing tunnel reaching −40°C (−40°F) in just 4 hours for tuna fillets.
Ultra-low temperature stores (ULT, −60°C to −86°C)
Ultra-low temperature (ULT) stores serve a specialised segment in healthcare and biopharmaceuticals, holding a stable temperature between −60°C and −86°C (−76°F to −123°F). −86°C (−123°F) is normally mandatory for mRNA vaccines and for storing critical biological samples. These systems must use cascade refrigeration with two different refrigerants to reach that depth of cold safely.
Classification of cold storage by function
By purpose, cold stores fall into six groups: processing stores, pre-cooling stores, distribution stores, retail stores, transport stores and domestic units. The core difference between them lies in their position in the supply chain, their design capacity and the daily frequency of movements in and out.
How does a distribution store differ from a transit store? A distribution store acts as a large central storage hub, typically 10,000 MT to 35,000 MT, holding goods long term with a modern WMS integrated. A cross-docking transit store, by contrast, is simply a collection point where product is cooled briefly before being loaded onto refrigerated vehicles.
| Warehouse type | Position in the chain | Typical capacity | Operating characteristics |
| Processing warehouse | Inside the plant | 500-5,000 MT | Highly variable load, large refrigeration capacity |
| Pre-cooling store | Before freezing | 50-200 MT | Short-term holding, surface cooling of product |
| Distribution store | Regional hub | 10,000-35,000 MT | Long-term storage, with automatic central monitoring |
| Commercial warehouse | Supermarkets, shops | 10-150 MT | Storage under 20 days, a wide range of products |
| Transport store | Containers, refrigerated vehicles | 5-25 MT | Mobile, temporary storage in transit |
| Domestic units | Households, F&B | Under 5 MT | Fridge and freezer cabinet format |
Classifying cold stores by storage capacity
Cold store capacity is expressed in MT (meat tons) — the standard unit of storage capacity in the industrial refrigeration sector. A 100 MT cold store holds around 100 tonnes (220,462 lbs) of frozen meat, equivalent to an actual storage volume of 250 m³ to 300 m³ (8,828 cu ft to 10,594 cu ft) depending on the stacking arrangement and loading density.
How does MT differ from m³? MT is a converted unit of the weight of goods, while m³ measures the physical volume of the store. How much floor area does a 50 MT store need? To reach that capacity, a store normally needs a floor area of around 60 m² to 80 m² (645 sq ft to 861 sq ft) with a ceiling height of 4–5 metres.
| Size | Capacity | Indicative floor area | Suitable for |
| Small | 5-50 MT | 10-70 m² | F&B chains, convenience stores, laboratories |
| Medium | 50-500 MT | 70-600 m² | Medium processing plants, supermarket chains |
| Big | 500-5,000 MT | 600-5,000 m² | Seafood export plants, logistics stores |
| Very large | Over 5,000 MT | Over 5,000 m² | Transhipment ports, national distribution centres |
Classifying cold stores by construction type
By construction, cold stores come in two forms: built stores (concrete walls with insulation applied inside) and modular panel stores (PU or EPS panels joined with camlocks). Panel stores now account for more than 90% of the industrial market in Vietnam, thanks to their very fast construction and the flexibility to dismantle and relocate them.
How do PU and EPS panels differ? A PU (polyurethane) core has a thermal conductivity of just 0.022 W/(m·K), markedly lower than the 0.035–0.040 W/(m·K) of an EPS core, making PU a far better insulator and ideal for deep-freeze stores.
| Criteria | Built store | Kho panel |
| Construction time | 4-6 months | 2–6 weeks |
| Investment costs | 30–50% higher | Optimal, faster return on investment |
| Dismantling | Fixed, cannot be relocated | Easy to dismantle and extend |
| Hygiene and appearance | Hard to clean, prone to condensation | Smooth surfaces, easy to wipe down, meets HACCP standards |
| Insulation life | As long as the building itself | 15–25 years (with PU panels at 38–40 kg/m³ density) |
| Suited to | Special heritage buildings | Most processing plants and commercial stores |
Classifying cold stores by refrigerant
By refrigerant, industrial cold storage systems in Vietnam use three main groups: NH3 (ammonia/R717), Freon (R404A, R507A, R134a) and CO2 (R744). The choice of refrigerant shapes the entire compressor configuration, the pipework and the associated safety standards.
Should you switch from R404A to CO2? The switch is entirely appropriate and necessary under the global HFC phase-down (the Kigali Amendment), as CO2 has a GWP (global warming potential) of 1 and is completely safe environmentally. Tân Long is one of the pioneers in Vietnam in completing industrial central NH3 refrigeration systems for major clients including Lotte F&G Vietnam, Frescol Tuna and C.P. Vietnam.
| Medium | Advantage | Limit | Suited to |
| NH3 (R717) | High COP, low cost, GWP = 0 | Toxic, pungent, requires a separate plant room | Seafood plants, processing complexes above 100 kW |
| R404A / R507A | Safe for people, easy to install | High GWP, being tightened under the protocol | Small and medium stores, retail stores |
| CO2 (R744) | GWP = 1, meets future green standards | High operating pressure (80–100 bar), expensive equipment | Premium stores, cascade systems with NH3 |
How do you choose the right type of cold store for your business?
Choosing the right cold store comes down to four central questions: at what temperature does the product need to be held, how many MT of storage are needed, where does it sit in the supply chain, and what is the available budget. Tân Long's standard technical consultancy process always begins with a site survey and an analysis of the product's physiology before arriving at a final configuration.
| Storage requirement | Recommended store type | Associated technical notes |
| Fruit and vegetables, flowers, pharmaceuticals | Chill room with 100 mm panels | Humidity must be tightly controlled at 85–95% |
| Frozen meat and seafood storage | Freezer store with 150 mm panels | An insulated, frost-protected floor is essential |
| Blast freezing shrimp and fish for export | Blast freezing tunnel or IQF conveyor | Product core temperature must be reached within 4 hours |
| Medical vaccine storage | ULT store using cascade technology | 24/7 monitoring and standby plant are mandatory |
| Logistics and distribution | Multi-zone distribution store | Integrated PLC/SCADA for centralised monitoring |
If your business needs a cold storage solution for storing food, the engineers will prioritise long-term temperature stability. For an export processing plant, wind tunnel combined with IQF conveyor is the optimum choice for the highest throughput. Every one of these compressor packs and evaporators is set up to run through PLC control cabinet for absolutely precise parameter control.
Frequently asked questions about cold store classification
Can a chill room be used for freezing?
No. A chill room is designed by default for the 0°C to 10°C range, so its compressor configuration and panel thickness cannot handle the deep sub-zero load of a freezing process. Forcing the system beyond its limits will damage the compressor, and converting it means replacing the equipment and the refrigerant entirely.
How many m³ of goods does a 100 MT cold store hold?
A 100 MT store gives around 250 m³ to 300 m³ (8,828 cu ft to 10,594 cu ft) of actual storage volume. That is equivalent to a gross store volume of 350 m³ to 400 m³ once you deduct the space for forklift aisles, air circulation clearances and the safety zone around the evaporators.
Should an industrial store use NH3 or Freon?
NH3 is entirely suited to large central refrigeration systems above 100 kW, thanks to its outstanding COP and low running costs. Freon, by contrast, is safer and suits stores below 100 kW or those located in residential areas where the risk of a chemical leak must be eliminated. Looking ahead, the Kigali road map is progressively phasing out high-GWP Freon, so larger businesses should consider CO2 or NH3 technology for new projects. This article has given a complete picture of the 5 criteria for classifying cold stores: temperature, purpose, capacity, construction and refrigerant. Choosing the right cold storage segment not only protects product quality and meets international standards but substantially optimises long-term operating budgets. Contact Tân Long's engineers now for in-depth advice and a completely free site survey for your project. See also: What is a refrigerated container? Features, construction and applications Cold storage for restaurants: choosing the right type, designing and installing it to F&B standards What is a GSP store? What makes a cold store GSP compliant?
Related pages
- How to store beef jerky in bulk: temperature standards and industrial cold storage systems
- Cold store design drawings: construction, process and how to read them
- Cold storage for restaurants: choosing the right type, designing and installing it to F&B standards
- Vietnam cold storage market 2026: potential and investment opportunities
- Tan Long industrial cold storage
Kỹ sư Nguyễn Toàn Thịnh (Giám đốc Kỹ thuật)
Hơn 18 năm kinh nghiệm thực chiến chỉ đạo tư vấn thiết kế và thi công hệ thống lạnh công nghiệp nặng, kho tự động ASRS và cấp đông IQF qua hơn 29 đại dự án quốc gia.
