NH3 refrigeration (ammonia, refrigerant R717) is the industrial cooling solution for seafood and food processing plants and large-scale cold stores. Tan Long designs, manufactures its own equipment, installs and maintains turnkey NH3 systems — with 29 projects delivered in Vietnam since 2005.
| Medium | NH3 (Amoniac) – R717 |
| Evaporating temperature range | -18°C to -40°C |
| Application | IQF freezing, air blast freezing tunnels, contact plate freezers, cold stores, chiller rooms, workshop air conditioning |
| Tan Long scope | Design – Manufacture – Supply – Installation – Commissioning – Maintenance |
| Equipment built in house | IQF freezer conveyors, contact plate freezers, air blast freezers, flake ice machines, evaporative condensers |
| Manufacturing plant | Duc Hoa 1 Industrial Park, Tay Ninh (formerly Long An) |
| Projects delivered | 29 projects |
When a plant should choose NH3 refrigeration
NH3 is the most economical choice when a plant meets all four conditions below. If one of them is missing, Freon or CO2 is usually the better fit.
- A large, concentrated cooling load. The more load there is, the wider the electricity cost gap between NH3 and Freon. For an industrial-scale processing plant that gap typically repays the extra investment within a few years.
- Continuous operation. The system has to run many hours a day for NH3's high efficiency to pay off. In an intermittently operated store the benefit drops sharply.
- Space for a dedicated machine room. NH3 requires the compressor pack to sit in a separate machine room with emergency ventilation. It cannot be installed as scattered stand-alone units the way Freon can.
- A trained operating team. This is the condition investors most often overlook. NH3 is safe when operated correctly, but it demands stricter procedures than Freon.
If a plant cannot meet conditions 3 and 4, Tan Long will normally recommend Freon or a combined system — rather than pushing an NH3 system through at all costs.
NH3, Freon and CO2 compared
These are the three common refrigerants in industrial refrigeration. None of them is best in every case — the right choice depends on load size, required temperature and site conditions.
| Criteria | NH3 (R717) | Freon (R404A, R507…) | CO2 (R744) |
|---|---|---|---|
| Cooling efficiency | Highest | Medium | High at very low temperatures |
| Refrigerant cost | Lowest | Expensive | Low |
| Ozone depletion | No | No (but has global warming potential) | No |
| Working pressure | Medium | Low | Very high |
| Toxicity | Yes – requires safety procedures | Low | Asphyxiant at high concentration |
| Dedicated machine room required | Mandatory | Not required | Recommended |
| Pipework material | Steel (NH3 corrodes copper) | Copper | High-pressure steel |
| Best suited to | Large plants running continuously | Small and medium stores, stand-alone units | Very low temperature ranges, cascade systems |
In practice many plants use a combined multi-refrigerant system: NH3 for the large load, Freon for small stand-alone units. Tan Long has delivered a combined CO2, NH3 and R404 configuration at the Lotte F&G Vietnam plant.
NH3 safety — where the specialist contractor and the trading contractor part ways
NH3 has a very distinctive pungent smell, detectable at concentrations far below the dangerous threshold. That is both an advantage — leaks are noticed early — and the reason the system has to be engineered properly from the start.
A properly built NH3 system must have at least the following layers of protection:
- Leak detection sensors in the machine room and in every area carrying refrigerant pipework, interlocked with the alarm.
- Emergency ventilation for the machine room, triggered automatically when a sensor exceeds the threshold.
- Safety valves and relief lines discharging to a safe location outside the building.
- A machine room separated from the production area, with its own emergency exit.
- Steel pipework — never copper, because NH3 corrodes copper and copper alloys.
- Operating procedures and technical documentation handed over to the plant's operating team.
These items are small against the total investment, but they are exactly what gets trimmed when quotations are compared on price alone. When you receive an NH3 quotation, ask the contractor to itemise the safety scope separately so the comparison is fair.
What Tan Long's scope covers
Tan Long delivers all six steps as one package, without separating design from execution.
| Stage | Content |
|---|---|
| 1. Survey and calculation | Measuring the site, calculating the cooling load from actual processing capacity, setting the temperature range for each zone |
| 2. System design | Selecting the compressor configuration, designing the NH3 pipework, laying out the machine room and the safety systems |
| 3. In-house manufacturing | IQF freezer conveyors, contact plate freezers, air blast freezers, flake ice machines, evaporative condensers — produced at Duc Hoa 1 Industrial Park, Tay Ninh |
| 4. Supply of imported equipment | Mycom compressors, Güntner air coolers, Danfoss valves and other specialist brands |
| 5. Installation and commissioning | Connection, pressure testing, vacuum pump-down, refrigerant charging, fine-tuning and acceptance |
| 6. Maintenance | Scheduled maintenance, fault rectification, spare parts replacement |
Why Tan Long manufactures its own equipment
Most refrigeration contractors in Vietnam work on a trading model: import the equipment, then install it. Tan Long builds the main equipment sets at its own factory in Duc Hoa 1 Industrial Park, Tay Ninh.
That creates three concrete advantages for the investor:
- Control over the schedule. No dependence on import delivery dates — usually the single biggest cause of project delay.
- Customised to the site. Conveyor, freezer and condenser dimensions are designed around the actual building, instead of forcing the building to fit off-the-shelf equipment.
- Fast repairs. Materials, drawings and the fabrication team are all in Vietnam. When something fails there is no wait for an overseas order.
A concrete example: at the Kyokuyo Vina Foods plant, 17 of the 33 main equipment sets on the project were built by Tan Long — including all 08 high-speed IQF freezer conveyors with a combined capacity of 4,300 kg/h, the contact plate freezers, 04 flake ice machines and 04 evaporative condensers.
NH3 refrigeration projects delivered by Tan Long
Below are some representative NH3 projects, with the scope actually delivered.
| Factory | Location | NH3 system scale |
|---|---|---|
| Meito Vietnam | Tan Duc Industrial Park, Tay Ninh | 30,000-pallet cold store · 07 Mycom screw compressors · 50 air coolers |
| Nichirei TBA Logistics | Long Hau Industrial Park, Tay Ninh | 20,000-pallet cold store (~165,600 m³) · 06 compressors · 34 air coolers |
| Meito Vietnam | Song Than II Industrial Park, Binh Duong | 20,000 MT cold store · 07 screw compressors |
| Frescol Tuna Vietnam | Nghi Loc, Nghe An | 12,000 MT frozen store · 06 air blast freezing tunnels |
| Kyokuyo Vina Foods | — | 08 high-speed IQF freezer conveyors, 4,300 kg/h · 05 Mycom compressors |
| Saigon Food | Vinh Loc Industrial Park, Ho Chi Minh City | 04 workshops · 13 Mycom reciprocating compressors |
| Vietnam Clean Seafood | An Nghiep Industrial Park, Soc Trang | IQF freezer conveyors · contact plate freezers · flake ice machines · 2,000-pallet cold store |
| Agrex Saigon | TP.HCM | 05 consecutive projects · 1,000-pallet cold store |
See all 29 projects delivered by Tan Long.
Equipment in an NH3 refrigeration system
- Refrigeration compressor — screw or reciprocating, depending on the capacity range and duty cycle
- Evaporative condenser — built by Tan Long, more energy efficient than air-cooled condensing in Vietnam's climate
- Industrial refrigeration system — distributing cooling to the stores and the processing areas
- IQF conveyor — individually quick freezing in 8–15 minutes
- Contact freezer and wind tunnel — block and tray freezing
- Flake ice machine — preserving raw material at intake and pre-processing
- Control cabinet and SCADA — monitoring and controlling the whole system
- Pressure vessel and cold storage panel
Two large-scale NH3 projects delivered by Tan Long
- NECS – New Era Cold Storage, Tay Ninh: 102,642 pallet positions, total cooling capacity of around 3.05 – 3.08 MW, 08 MYCOM screw compressors arranged on two pressure stages, and a -40°C blast freezing tunnel rated at 44,250 kg per batch. Tan Long delivered the work across three phases in 2024, 2025 and 2026.
- AJ Total Vietnam – Long Hau Industrial Park, Tay Ninh: a cold storage centre of approximately 30,700 pallet positions, with an ASRS automated freezer store over 40 m high rated at 515.2 kW, 06 Mycom compressors and 25 Güntner air coolers. Tan Long delivered the main system in 2019 – 2021 and additional scope in 2023 and 2024.
An NH3 system has its own requirements for the electrical control scope because of the refrigerant's safety characteristics — see control panels for NH3 refrigeration systems.
Frequently asked questions about NH3 refrigeration
What is an NH3 refrigeration system?
An NH3 refrigeration system is an industrial cooling system using ammonia (refrigerant R717). NH3 offers the highest cooling efficiency among the common industrial refrigerants in the evaporating range from -18°C to -40°C, the refrigerant itself is inexpensive, and it does not deplete the ozone layer. It is the most common choice for seafood and food processing plants and large-scale cold stores in Vietnam.
NH3 or Freon — which is better for a factory cold store?
It depends on scale. NH3 is more economical with a large cooling load, continuous operation, space for a dedicated machine room and a trained operating team. Freon suits small and medium stores, stand-alone units, or sites where a separate machine room is not possible. Many plants use a combined system: NH3 for the large load, Freon for the small units.
Is an NH3 system safe?
NH3 is safe when it is designed and operated correctly. Ammonia has a distinctive pungent smell detectable well below the dangerous concentration, so leaks are usually noticed early. A compliant system needs leak detection sensors, emergency ventilation for the machine room, safety valves with relief lines to the outside, a machine room separated from the production area, and steel pipework.
Why must NH3 pipework be steel rather than copper?
NH3 corrodes copper and copper-bearing alloys. All pipework, valves and fittings in an NH3 system must be steel. This is a fundamental difference from Freon systems, which use copper tube, and one of the reasons an NH3 system calls for a contractor with specific experience.
How many NH3 refrigeration projects has Tan Long completed?
Tan Long has designed, manufactured and installed refrigeration systems for 29 projects in Vietnam, most of them NH3 — seafood, food and beverage processing plants and cold chain logistics centres. The largest are a 30,000-pallet cold store at Meito Vietnam (Tan Duc Industrial Park) and a 12,000 MT frozen store at Frescol Tuna Vietnam (Nghe An). See the full project list.
Does Tan Long manufacture its own equipment or only import?
Tan Long builds IQF freezer conveyors, contact plate freezers, air blast freezers, flake ice machines and evaporative condensers at its plant in Duc Hoa 1 Industrial Park, Tay Ninh. Specialist equipment such as Mycom compressors, Güntner air coolers and Danfoss valves is imported from the manufacturer. On the Kyokuyo Vina Foods project, 17 of the 33 main equipment sets were built by Tan Long.
How long does it take to build an NH3 refrigeration system?
It depends on the scale and complexity of the project. Tan Long surveys the site and calculates the real cooling load before committing to a schedule. Manufacturing the equipment in house keeps the schedule under Tan Long's own control, with no dependence on import delivery dates.
Does Tan Long maintain NH3 systems installed by other contractors?
Yes. Tan Long provides scheduled maintenance and fault rectification for industrial refrigeration system, including systems installed by other companies. Call 0933 357 058 (Mr. Thinh) to arrange a survey.
Request advice and an NH3 system quotation
Tan Long surveys the site, calculates the cooling load from actual processing capacity and quotes for a turnkey NH3 system. Call 0933 357 058 (Mr. Thinh) or send a quotation request.
Related technical reading
- types of refrigerant
- safety when operating and repairing refrigeration systems
- compressors for NH3 systems
Related pages
- Turnkey industrial cold storage contractor
- 29 projects delivered by Tan Long
- What is a refrigeration system? Types of industrial refrigeration
- Cold storage installation to standard – step by step
- About Tan Long – industrial cold storage contractor since 2005
- Industrial cold storage design consultancy
- Industrial cold storage maintenance
