A cold store is an insulated building that uses an industrial refrigeration system to hold storage temperatures from 10°C (50°F) down to −45°C (−49°F). Understanding how to make cold storage lets an investor supervise construction, compare contractor quotations and avoid unreasonable cost increases.
Cold stores fall into three main types by temperature: chill rooms (0–10°C), freezer rooms (−18°C to −25°C) and blast freezing rooms (−35°C to −45°C). The main materials are PU insulated panels (density 38–42 kg/m³, thermal conductivity 0.022 W/mK), cold room doors, and the compressor, evaporator and condenser system. Construction runs to seven steps, from site survey to handover.
This article brings together the technical standards, the common construction faults and a contractor selection checklist, drawn from more than 20 years of Tân Long designing and installing industrial refrigeration systems.
This article explains the principles. If you need a company to do the whole job, see Tân Long’s cold storage construction service — from site survey to operational handover.
What is a cold store and how does it work?
Cold storage is an insulated building that uses an industrial refrigeration system to hold temperatures from 10°C (50°F) down to −45°C (−49°F). It stores food, seafood, pharmaceuticals and produce to the temperature standard of each sector.
A cold storage room differs from a domestic freezer and a refrigerated container in three ways:
- A cold store is a permanent structure with insulated panels 50–200 mm (2–8 inches) thick.
- The refrigeration system has high capacity, using industrial compressors rather than small condensing units.
- Store volume runs from a few dozen to thousands of cubic metres, serving industrial-scale production.
The refrigeration system works on the vapour compression cycle. The refrigerant — NH3 (ammonia) for industrial stores or R404A/R507 for smaller ones — absorbs heat from the store through the evaporator and rejects it outside through the condenser. Cold stores are then classified by their operating temperature.
Common cold store types and their operating temperature ranges
Cold stores fall into three main types by temperature: cool storage (0°C–10°C / 32°F–50°F), freezer stores (−18°C to −25°C / 0°F to −13°F) and blast freezing rooms (−35°C to −45°C / −31°F to −49°F). Each serves a different sector and needs a different panel thickness.
| Warehouse type | Temperature | Humidity | Sector served | Panel thickness |
| Cool storage | 0–10°C (32–50°F) | 85–95% | Fruit and vegetables, dairy, pharmaceuticals, cut flowers | 50–75mm (2–3 inches) |
| Cold storage | −18 to −25°C (0 to −13°F) | 80–90% | Seafood, meat, frozen food | 100–150mm (4–6 inches) |
| Freezer | −35 to −45°C (−31 to −49°F) | 75–85% | Seafood for export, IQF, fast freezing | 150–200mm (6–8 inches) |
Chill rooms (0°C – 10°C / 32°F – 50°F)
A chilled store holds temperatures above freezing to keep produce fresh without icing it. High humidity of 85–95% stops fruit and vegetables drying out. Insulated panels of 50–75 mm (2–3 inches) handle the moderate temperature difference between inside and outside.
Freezer stores (−18°C to −25°C / 0°F to −13°F)
A frozen store holds goods long term. Panels need to be 100–150 mm (4–6 inches) thick to limit heat loss through the walls. A frozen store requires strict condensate management: the door gaskets must seal and the gasket heaters run continuously to prevent icing.
Blast freezing rooms and air blast tunnels (−35°C to −45°C / −31°F to −49°F)
A blast freezer and an wind tunnel (air blast freezer) bring the product down to −18°C within 4–8 hours. This type serves the seafood export industry and IQF freezing lines (individual quick freezing). Panels need to be 150–200 mm (6–8 inches) thick and the cooling capacity 2–3 times that of an ordinary freezer store. Panel thickness and equipment type change with each type of store.
Cold store materials: insulated panels, doors and refrigeration equipment
A cold store’s main materials fall into three groups: insulated panels, cold room doors, and the industrial refrigeration system. Material quality determines 60–70% of the store’s performance and service life.
PU and EPS insulated panels — thickness, thermal conductivity and applications compared
PU (polyurethane) and EPS (expanded polystyrene) panels are the two common insulating materials in cold store construction. PU insulates 35–40% better than EPS at the same thickness.
| Criteria | PU Panel | EPS Panel |
| Density | 38–42 kg/m³ | 15–25 kg/m³ |
| Thermal conductivity (U-value) | 0.022 W/mK | 0.034 W/mK |
| Common thicknesses | 50 / 75 / 100 / 150 / 200mm | 50 / 75 / 100mm |
| Moisture resistance | High – water absorption <2% | Moderate – water absorption 3–5% |
| Price | 30–40% higher | Affordable |
| Life expectancy | 20–25 years | 10–15 years |
| Application | Freezer rooms, blast freezing rooms, pharmaceuticals | Chill rooms, limited budget |
Cold room doors: sliding, hinged and high-speed
There are three main types of cold room door. Sliding doors suit industrial stores with wide openings and regular forklift traffic. Hinged doors suit small stores opened infrequently. High-speed doors go at loading bays to reduce cooling loss where the door opens constantly. Tân Long manufactures the T-Light cold room door range with triple gaskets and an aluminium frame rated for deep sub-zero temperatures.
Compressors, condensers and industrial evaporators
An industrial refrigeration system has three main groups of equipment. The compressor is the heart of the system; Bitzer, Copeland and Mycom are widely used. Screw compressors suit high capacity, piston compressors suit smaller stores. Evaporative condensers reject heat efficiently in Vietnam’s hot, humid climate.
Industrial unit coolers come in two forms: herringbone evaporators for blast freezing rooms and fan-type evaporators for chill rooms. NH3 (ammonia) is used for large industrial stores; R404A and R507 suit smaller stores and pharmaceutical storage. Once the materials are chosen, the next step is installation in the correct sequence.
Building a cold store from A to Z: seven design and installation steps
Building a cold store takes seven steps: site survey, technical design, floor preparation, panel installation, door installation, refrigeration system installation, and commissioning and handover. The order of work directly affects the store’s performance and service life.
Step 1: Site survey and heat load calculation
The first step is the site survey and heat load calculation. The engineering team measures the space, checks the floor is level within a tolerance of ≤3 mm over 2 m, and assesses the floor loading. An industrial store needs a floor rated for at least 1.5 tonnes/m².
The heat load calculation covers: heat through the walls and ceiling, heat from incoming goods, and heat from lighting, workers and forklifts. On seafood cold storage projects, the Tân Long team always measures floor moisture before installation. A floor above 60% moisture needs waterproofing before work begins.
Step 2: Technical design and construction drawings
Cold store design drawings cover the overall layout, evaporator and condenser positions, airflow direction and the pipework schematic. Power and control drawings (PLC or SCADA panel) are produced in parallel. The design has to specify the maximum stacking height and a minimum clearance of 150 mm (6 inches) between goods and walls so air circulates evenly.
Step 3: Floor preparation and the ventilation duct system
Floor preparation is an important step many contractors skip. The ventilation ducts measure 300 mm wide by 200 mm high (12×8 inches), spaced 400–500 mm (16–20 inches) apart. This system prevents condensation beneath the floor and stops frost heave from the temperature difference.
A bitumen or 0.2 mm PE film waterproof layer is laid over the floor before the floor panels go down. On a 500 MT freezer project in Sóc Trăng, the Tân Long team found the floor heaving where the previous contractor had omitted the ventilation ducts, with the floor surface temperature 5°C above design.
Step 4: Installing floor, wall and ceiling panels
Panel installation order: floor → walls → ceiling. Floor panels sit on the ventilation ducts, with joints sealed using heat-resistant silicone. Wall panels lock together with cam-locks, with a permitted joint gap of ≤1 mm. Ceiling panels hang from stainless steel supports designed to carry the evaporators and refrigerant pipework. Every panel joint must be completely sealed to prevent thermal bridging and condensation.
Step 5: Fitting the cold room doors and aluminium coving
Panels are cut to the designed door opening. The aluminium or stainless steel door frame is fitted together with anti-condensation coving. The technician checks that the door gasket seals and that the gasket heater (where fitted) runs at the correct rating. A poorly sealing gasket is the leading cause of cooling loss and evaporator frosting.
Step 6: Installing the refrigeration system: compressor, evaporator, pipework and refrigerant
The compressor is mounted on anti-vibration feet, with ACR-grade copper tube connections. Every pipe joint has to be brazed with a nitrogen purge to prevent internal oxidation. Once the pipework is complete, the system is evacuated to ≤500 microns and held for 4 hours without rising.
The Tân Long team applies a double evacuation procedure on every project: first down to 500 microns then broken with nitrogen, then a second evacuation to ≤500 microns held for 4 hours. This removes residual moisture completely, extends compressor life and reduces the risk of moisture blockage in the expansion valve. The refrigerant is then charged to the designed weight.
Step 7: Commissioning, balancing and handover
The system runs continuously for 4–8 hours to confirm it reaches setpoint. The temperature difference between zones must be ≤2°C. Compressor current must be steady and not exceed 105% of rated capacity. The handover file includes as-built drawings, the warranty booklet and operating instructions for the investor’s technical team.
Technical standards a cold store must meet after installation
Once installed, a cold store has to meet standards for temperature, humidity, stacking and refrigeration safety. These parameters directly affect storage quality and monthly running costs.
| Criteria | Standard value | Note |
| Temperature difference between zones | ≤2°C | Check with a thermometer at 5 points in the store |
| Clearance between goods and walls | ≥150mm (6 inches) | Ensures air circulates around the goods |
| Clearance between goods and ceiling | ≥300mm (12 inches) | Does not obstruct the airflow from the evaporator |
| Floor loading | ≥1.5 tonnes/m² | Industrial store with forklifts |
| Condensate drainage | Discharged outside the store | With a trap against odour and freezing |
| Safety certification | HACCP, ISO 22000 | Mandatory for food export storage. GSP/GDP for pharmaceuticals. |
Meeting the standard at handover is only the start. Holding it requires the right operating and maintenance routine.
How should a cold store be operated and maintained after installation?
A cold store needs scheduled maintenance to hold its performance and equipment life. The usual cycle: monthly for the evaporators (defrost, clean the fins), every 3–6 months for the compressor (measure current, check refrigerant, change oil), and annually for the whole system (check panels, door gaskets, electrical system).
Many failures, however, come not from operation but from the original construction. Here are the common faults and how to avoid them.
Common cold store construction faults and how to avoid them
Cold store construction faults usually occur in three areas: floor preparation, panel installation and refrigeration system installation. Spotting them early keeps repair costs down and avoids damage to the goods.
| Fault | Cause | How to avoid them |
| Floor heave | Missing ventilation ducts, or ducts of the wrong size | Build the ducts correctly at 300×200 mm, spaced 400–500 mm |
| Condensation on panels | Panel gaps >1 mm, door gasket not sealing | Seal the joints fully with silicone, replace gaskets every 6–12 months |
| Refrigerant leaks | Poor brazed joints, inadequate evacuation | Braze with a nitrogen purge, evacuate twice to ≤500 microns |
| Evaporator frosting up | Defrost timer set wrongly, door gasket not sealing | Adjust the defrost cycle, check the gasket monthly |
| Cold room door not sealing | Door frame fitted out of alignment, hinges sagging | Realign the hinges, replace the gasket, check the heater |
On a 500 MT freezer project in Sóc Trăng, the Tân Long team found the floor heaving after 6 months in service because the previous contractor had skipped the ventilation ducts. The repair cost three times what doing it properly would have. Many faults trace back to choosing an inexperienced contractor.
Choosing a cold store contractor: an A to Z assessment checklist
Choosing a cold store contractor means assessing seven criteria: industry experience, manufacturing capability, reference projects, warranty terms, scheduled maintenance, an emergency hotline, and technical certification.
| Criteria | Questions to ask the contractor | Importance |
| Experience | How many years has the contractor been in the industry? Have they built projects of this size? | ★★★ Very high |
| Manufacturing capability | Do they have their own equipment factory, or do they only assemble? | ★★★ Very high |
| Reference projects | A list of completed projects? Any case studies? | ★★★ Very high |
| Warranty | How long is the refrigeration system warranty? (standard: 12–24 months) | ★★ Cao |
| Regular maintenance | Is there a 3–6 month maintenance package? A 24/7 emergency hotline? | ★★ Cao |
| Certification | ISO 9001, HACCP? Any refrigeration industry technical certification? | ★★ Cao |
| Engineering team | Are the engineers professionally trained? Do they hold copper brazing certificates? | ★ Moderate |
Tân Long meets all of these criteria, with more than 20 years of experience, a factory in Duc Hoa 1 Industrial Park (Tây Ninh, formerly Long An), and more than 100 flagship cold storage projects for Lotte, C.P. Vietnam, Kyokuyo Vina Foods, Frescol Tuna and many seafood exporters. Our management system meets HACCP and ISO standards.
Frequently asked questions about building a cold store
How much does a cold store cost to build?
The cost of building a cold store depends on size, temperature and materials. A small store of 20–50 m³ runs from 150–350 million VND. An industrial store of 500 m³ and above runs from 1.5–5 billion VND. What pushes the cost up: imported compressors, NH3 refrigerant, and a SCADA control system.
Should you build a small cold store yourself at home?
An investor can install a store under 10 m³ themselves given refrigeration knowledge and panel installation experience. Anything above 10 m³ needs a professional contractor to ensure refrigeration safety, floor loading and the designed cooling performance.
PU or EPS panels: which suits a cold store better?
PU panels insulate 35–40% better than EPS at the same thickness, suiting freezer and blast freezing rooms. EPS suits chill rooms on a limited budget. For stores below −18°C, PU is the standard choice.
How does industrial cold storage differ from a mini cold room?
An industrial cold store has a volume of 100 m³ or more and uses a central refrigeration system (NH3 or parallel compressor racks). A mini store under 50 m³ uses a single condensing unit, installs faster and costs less. An industrial store requires floor preparation, ventilation ducts and a PLC/SCADA control system.
Take control of cold store quality from the design stage
Building a cold store to standard takes quality materials, a disciplined seven-step construction process and a contractor with real experience. The panels and the refrigeration system determine 60–70% of the store’s performance. The order of work — particularly floor preparation and evacuating the pipework — directly affects how long the installation lasts.
An investor should use the seven-criteria checklist to assess contractors and supervise each step of the work. With more than 20 years building industrial refrigeration systems, Tan Long is ready to advise on the design and installation of a compliant cold store at any scale and in any sector. Contact the Tân Long engineering team for a free survey and quotation.
Contact information:
- Head office: 86 Dong Den, Tan Binh Ward, Ho Chi Minh City, Vietnam
- Factory: Lot MM3-2, Road No. 04, Duc Hoa 1 Industrial Park, My Hanh Commune, Tay Ninh Province, Vietnam
- Mail: info@tanlongvn.com
- Opening hours: Monday – Saturday, 8:00 AM – 5:30 PM
- Hotline: 02838494943
Related pages
- Cold store classification: 5 technical criteria and how to choose the right type
- Storing dried squid in bulk in a cold store: temperature and humidity standards
- Cold store repair: how to identify faults and the expert troubleshooting process
- How to store beef jerky in bulk: temperature standards and industrial cold storage systems
- Tan Long industrial cold storage
Doanh Nghiệp Đang Cần Khảo Sát, Nâng Cấp Hoặc Thiết Kế Mới Hệ Thống Lạnh Công Nghiệp?
Đội ngũ kỹ sư Cơ Điện Lạnh Tân Long với hơn 18 năm kinh nghiệm thực chiến chỉ đạo hơn 29 đại dự án quốc gia, cam kết tư vấn tính toán phụ tải nhiệt chuẩn xác, tối ưu hóa hệ số hiệu suất COP, chuyển dịch môi chất tự nhiên NH3/CO2 và tiết kiệm 20–30% chi phí điện năng vận hành.
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.
