Industrial Refrigeration Compressors

Refrigeration compressor (also known as a cooling compressor) is the central device in every industrial refrigeration system. It draws low-pressure refrigerant vapour from the evaporator, compresses it to high pressure, then discharges it to the condenser to reject heat. The entire cooling capacity of the system depends on how stably the compressor runs. Tan Long supplies industrial refrigeration compressor packs running on NH3 (ammonia) and Freon (R404A, R134a, R507), suited to cold stores, seafood plants and high-capacity food processing lines.

What is a refrigeration compressor and how does it work?

A refrigeration compressor is a mechanical device that raises pressure refrigerant from low-pressure saturated vapour to high-pressure superheated vapour. The compression cycle runs continuously in four steps: suction from the evaporator, adiabatic compression, discharge into the condenser, and expansion through the expansion valve. The efficiency of this process sets the coefficient of performance (COP) of the whole system.

In an industrial NH3 refrigeration system, suction pressure ranges from 1.5 bar to 4.5 bar (21.8 psi to 65.3 psi), while discharge pressure reaches 10 bar to 18 bar (145 psi to 261 psi), depending on the design evaporating and condensing temperatures. With Freon systems the pressure range differs by refrigerant. Understanding these two parameters correctly is what lets an engineer select the right compressor pack for each application.

Compressor cluster at Tan Long

Refrigerants and their application in compressor systems

The choice of refrigerant is the decisive factor in determining the type of refrigeration compressor, the overall design approach and the long-term operating cost for the business. Below are the most common refrigerants Tan Long applies in real projects:

NH3 (ammonia, designation R717): This is a fully natural refrigerant that does no harm to the ozone layer and offers the highest thermodynamic efficiency of any commercial refrigerant in use today. Tan Long regularly designs and builds NH3 systems for large-scale cold storage projects holding from 500 tonnes to more than 12,000 tonnes of product. These systems require a refrigeration compressor rated for high pressure, and the pressure vessels that go with it must comply strictly with the TCVN 6843 technical safety standard.
HFC and HFO (Freon such as R404A, R134a, R507A, R448A): These refrigerants suit small and medium refrigeration systems particularly well, thanks to their low toxicity and straightforward installation and maintenance. Freon is commonly used in chiller rooms for agricultural produce, in water chiller systems and in mid-capacity mesh belt IQF freezer lines. Combining this refrigerant with the right refrigeration compressor piston or screw type optimises cooling performance for food and pharmaceutical processing plants.
CO2 (designation R744): This is the new green technology trend in the global food refrigeration industry, with a GWP (Global Warming Potential) of approximately 1. It does, however, impose very high technical demands, because the refrigeration compressor has to operate at extremely high pressure, ranging from 50 to 100 bar. That calls for a more complex and precise system design, requiring accurate calculation by Tan Long's experienced engineering team to ensure safety.

Outstanding features of refrigeration compressor

How to select the right refrigeration compressor for a system

Selecting a refrigeration compressor depends on four key technical parameters: the required cooling capacity (kW or RT), the design evaporating temperature, the condensing temperature at the installation site, and the refrigerant used.

Step 1 – Calculate the cooling load: The total cooling load comprises heat gain through the building envelope, the load from the goods being cooled, and the load from equipment and lighting inside. It is expressed in kW or RT (1 RT is 3.517 kW, or 12,000 BTU/h).
Step 2 – Determine the evaporating temperature: Frozen storage (-18°C to -25°C) requires an evaporating temperature of about -30°C to -35°C. A quick-freezing tunnel (-35°C to -40°C) requires an evaporating temperature of -45°C to -50°C.
Step 3 – Check COP and electricity consumption: The higher the COP, the lower the running cost. A modern screw compressor achieves a COP of 3.0 to 4.5 at an evaporating temperature of -10°C and condensing at +35°C. Annual electricity consumption (kWh) determines the lifetime cost of the equipment, not just the initial purchase price.
Step 4 – Select the refrigerant: NH3 (R717) has the advantage in COP and causes no greenhouse effect (GWP of 0), but requires a sealed system and safety-trained staff. Freon suits small and medium systems and is easier to maintain.

Industrial applications of refrigeration compressor systems

Tan Long is a trusted contractor that has installed refrigeration compressor systems at many major projects in Vietnam's food and seafood processing industry. Below are typical applications that demonstrate the performance of the equipment Tan Long supplies:

Industrial cold storage systems: On large-scale cold storage projects, Tan Long deploys NH3 systems combined with refrigeration compressor screw units rated from 150 to 300 HP. This keeps freezer rooms stable at -18°C to -25°C (approximately -0.4°F to -13°F) and chiller rooms at 0°C to +5°C (approximately 32°F to 41°F).
Seafood processing plants: For quick-freezing systems that need an evaporating temperature down to -40°C (approximately -40°F), Tan Long favours refrigeration compressor two-stage piston units or high compression-ratio screw compressors to meet the demanding freezing-time requirement.
Frozen food production: Core equipment such as wind tunnel, contact freezer or IQF freezer conveyors all need a refrigeration compressor capable of running reliably for 20 to 22 hours a day.
Water chiller solutions: For process water chilling in the 5°C to 12°C range (approximately 41°F to 54°F), Tan Long applies screw refrigeration compressors combined with water-cooled or air-cooled heat rejection depending on the site.

Selected projects using refrigeration compressor systems supplied by Tan Long: Major partners such as Kyokuyo Vina Foods, Lotte F&G Vietnam, C.P. Vietnam, Frescol Tuna Vietnam and Ca Mau Seafood all run refrigeration compressor systems designed and installed directly by Tan Long's engineering team.

The most common types of industrial refrigeration compressor

In modern refrigeration engineering, choosing the right refrigeration compressor accounts for up to 70% of the efficiency and service life of the whole system. On projects delivered by Tan Long , Tan Long works mainly with three compression technologies: screw, piston (reciprocating) and scroll.

The comparison table below helps investors choose:

Compressor type	Capacity range	Suitable refrigerants	Typical applications
Screw	50 kW – 1.500 kW	NH3, R134a, R404A	Large cold stores, Mesh belt IQF freezer, seafood plants
Piston (Reciprocating)	5 kW – 200 kW	NH3, R22, R404A	Freezing rooms, small and medium chiller rooms
Scroll	3 kW – 50 kW	R410A, R134a, R404A	Water cooled chiller, commercial refrigeration systems

1. Screw refrigeration compressors

Refrigeration compressor screw compressors work on the principle of two meshing helical rotors compressing the refrigerant continuously. The advantage of this type is that it has no suction or discharge valves, so it runs extremely smoothly with minimal mechanical vibration.

The slide valve technology allows capacity to be modulated from 10% to 100%, saving significant electricity when the load varies. Tan Long typically applies refrigeration compressor NH3 screw units to large cold storage systems from 5,000 tonnes upwards, or to high-capacity food processing plants.

Reference specifications for Tan Long NH3 screw compressor packs:

Cooling capacity: 150 kW – 1,200 kW (approximately 511,000 – 4,095,000 BTU/h)
Motor power: 37 kW – 315 kW
Rotational speed: 2,950 rpm (50 Hz)
Evaporating temperature: -40°C to +10°C
Maximum compression ratio: 1:20
Typical COP: 2.5 – 4.5

2. Piston (reciprocating) refrigeration compressors

This is the line refrigeration compressor is the traditional type, but it remains important thanks to its ability to reach very high compression ratios, suited to deep freezing down to -50°C.

In the Vietnamese market, especially at seafood plants in the Mekong Delta, refrigeration compressor semi-hermetic NH3 piston units are popular for wind tunnel or for individual packs from 20 kW to 100 kW. Their biggest advantage is durability, easy maintenance and ready availability of spare parts at Tan Long's own factory.

3. Scroll refrigeration compressors

Compact and efficient at low capacity, refrigeration compressor scroll compressors are the first choice for Water chillers serving central air conditioning or cooling small production lines. With few moving parts, this type minimises minor breakdowns over long service life.

NH3 versus Freon refrigeration compressors compared

Choosing between refrigeration compressor running NH3 (ammonia) or Freon (such as R404A, R507) is a strategic decision that directly affects a company's long-term operating cost. Below is a detailed analysis based on real installation experience at Tan Long:

Comparison criteria	NH3 refrigeration compressors (R717)	Freon refrigeration compressors (R404A/R507)
Environmental rating	GWP of 0, ODP of 0 (environmentally friendly)	GWP 3,260 – 3,985 (high global warming impact)
COP (-10/+35°C)	4.0 – 4.8 (very high efficiency)	2.8 – 3.5 (moderate efficiency)
Popular Applications	Large cold stores, seafood plants, IQF	Medium cold stores, supermarkets, F&B
Operating costs	15% – 25% lower	Higher, because COP is lower
Safety requirements	Very high (leak detection system required)	Medium
Service life	20 – 30 years	15 – 20 years

Since 2020 the Vietnamese market has shifted noticeably. Seafood processing plants and cold storage facilities above 3,000 MT are moving to refrigeration compressor NH3 packs. The aim is to cut electricity costs as far as possible and to meet strict international environmental standards such as greenhouse gas reduction commitments.

A system refrigeration compressor NH3 designed by Tan Long's engineers and installed correctly will have a very low refrigerant leakage rate, under 0.5% per year to ASHRAE Standard 15-2019.

Advice from Tan Long's specialists:

If you operate a large production facility and value durability beyond 20 years, an refrigeration compressor NH3 pack is the most economical answer.
For smaller systems that need to be compact with low initial investment, refrigeration compressor running Freon, integrated into a water chiller package or a chiller room, is the better fit.

To keep the system safe and running at peak efficiency, Tan Long recommends adding SCADA monitoring to track refrigerant concentration and compressor status 24/7.

Standard maintenance procedure for industrial refrigeration compressors

Scheduled maintenance of the refrigeration compressor is the prerequisite for keeping the coefficient of performance (COP) stable and extending the service life of the whole system. For industrial refrigeration compressor NH3 screw units, Tan Long recommends a strict technical programme in three stages: monthly maintenance, six-monthly inspection, and a major overhaul every 3 to 5 years of operation.

During the monthly and six-monthly checks, the technical team should focus on these core operating items:

Monthly operating parameter check: Monitor oil pressure and the actual lubricant level. Pay particular attention to discharge temperature, which must not exceed 90°C, and to mechanical vibration, which must stay below 4.5 mm/s RMS to ISO 10816, in order to protect the refrigeration compressor from physical damage.
Six-monthly scheduled maintenance: Change the specialist lubricating oil, clean the oil filter and check the function of the safety valves. This is also the time to measure motor insulation resistance and check the signals at the PLC control panel so that every machine protection scenario stays ready.

When the system reaches its overhaul interval (every 3 to 5 years), the refrigeration compressor is fully stripped down to regrind the rotors, replace the bearings, and inspect the slide valve and coupling thoroughly. This deep maintenance restores the original compression efficiency and prevents sudden shutdowns that interrupt production. Tan Long provides scheduled maintenance and on-site technical support for every cold storage, IQF freezer conveyor and air blast freezing tunnel system it has installed.

Why choose Tan Long for refrigeration compressors?

Tan Long is a refrigeration engineering joint stock company with more than 20 years in industrial refrigeration, serving seafood and food processing plants and large-scale cold stores across Vietnam.

In-house manufacturing: its own factory in Duc Hoa 1 Industrial Park, Tay Ninh (formerly Long An), with no dependence on outside subcontractors.
Turnkey D&B capability: design and construction under one roof, reducing the risk of a gap between the drawings and what is actually installed.
Complete documentation: equipment is handed over with technical files and CO/CQ certificates of origin.
Engineers with field experience: advice based on each plant's actual system configuration rather than selling from a catalogue.
Support after handover: the technical team is on hand for operation and maintenance throughout the equipment's life.

For advice on a specific configuration, please contact Tan Long's engineering team or see the projects already delivered.

Optimised industrial compressor pack solutions from Tan Long

Tan Long does not simply supply individual machines — it delivers a complete refrigeration compressor unit (compressor unit) solution. The whole system comes pre-assembled on a rigid steel skid, saving floor space and shortening installation time on site.

Every refrigeration compressor designed by Tan Long integrates the full set of auxiliary and control equipment:

Main compressor: selected from specialist international brands (screw or piston).
Separation and filtration: high-efficiency oil separator and a liquid separator to protect the compressor.
Safety and instrumentation: safety valves, pressure gauges and precision solenoid valves.
Control system: PLC control cabinet or SCADA monitoring system for intelligent operation and prompt fault alarms.

Before leaving Tan Long's factory, every refrigeration compressor goes through strict quality control: pressure testing, charging with specialist oil and a test run, so the equipment works from the moment it is handed over.

With more than 20 years in industrial refrigeration installation, Tan Long is a strategic partner to many large groups. Its high-capacity refrigeration compressor packs have been running reliably at landmark projects:

Kyokuyo Vina Foods: An NH3 system using a pack of 05 refrigeration compressor Mycom screw compressors for 08 IQF conveyor plus NH3 refrigeration for the whole plant.
Frescol Tuna Vietnam (Nghe An): compression solutions for the export tuna processing line.
C.P. Vietnam (Cu Chi): freezing and food storage systems to international standard.

Real experience on projects of this scale is the measure of the design standard and reliability of the refrigeration compressor Tan Long builds.

Mycom compressor cluster

Why choose a Tan Long compressor pack solution?

Choosing a trusted company to supply and install a refrigeration compressor affects more than the initial investment — it determines the stability of the entire cold chain. Tan Long designs its solutions around energy efficiency and operating reliability. Every refrigeration compressor leaves the factory with a PLC controller programmed for multi-layer protection: high and low pressure control, discharge temperature monitoring, low oil level alarm and motor overload protection. The control panel is fully compatible with SCADA connectivity, so the plant can monitor remotely in real time and respond to faults promptly.

What sets Tan Long apart is its manufacturing capability and field experience in Vietnam's refrigeration engineering industry:

Manufacturing capability: Tan Long's plant in Tay Ninh (formerly Long An) operates to ISO and HACCP standards, ensuring precision in machining and pipework assembly for the refrigeration compressor.
Team of experts: With more than 20 years of specialist experience in NH3 systems, Tan Long's engineers support customers directly from the survey stage, cold storage design through to commissioning.
A matched equipment ecosystem: A refrigeration compressor reaches peak efficiency only when it works in step with supporting equipment such as industrial refrigeration absorbing heat, condensers rejecting heat, and pressure vessel (high-pressure receivers, oil separators) regulating refrigerant flow steadily.

Tan Long – a trusted contractor for industrial refrigeration installation

All of these components are managed centrally through the PLC control panel, optimising operating capacity and cutting wasted electricity.

To receive in-depth technical advice and updated detailed pricing information on the modules. refrigeration compressor genuine equipment, please contact Tan Long via Hotline: (+84) 933 357 058. Tan Long's specialists are ready to survey your site and propose the most efficient and durable technical solution for your business.

MYCOM compressors on real Tan Long projects

NECS – New Era Cold Storage, Tay Ninh: 08 MYCOM screw compressors arranged on two pressure stages. The low-stage group, model MCN250MB-L/51, delivers about 662.3 kW in freezer-room duty and 415.4 kW in -40°C freezing duty. The high-stage group, model MCN200M-L/51, delivers about 942.0 kW.
AJ Total Vietnam – Long Hau Industrial Park: 06 Mycom screw compressors for the central NH3 system serving the ASRS automated freezer store and the conventional stores.

Equipment that works alongside the compressor

The compressor is only one link. Real system efficiency depends on whether the following four equipment groups are matched to each other:

Industrial refrigeration system — the cooling side. Choose the wrong heat transfer area and the compressor either runs overloaded or runs under load; both waste electricity.
Evaporative condenser — the heat rejection side. Poor heat rejection raises discharge pressure, which pulls the compressor's power consumption up with it.
Pressure vessel — receivers, liquid separators, intermediate vessels. Too little or too much volume both affect system stability.
Control cabinet — decides which stage the compressor runs on and how it is protected when a fault occurs.

See the full range of industrial refrigeration equipment built by Tan Long.

Frequently asked questions about refrigeration compressors

What is the difference between screw and piston refrigeration compressors?

A screw compressor compresses refrigerant continuously with two helical rotors, suiting capacities from 50 kW upwards and varying loads. A piston compressor compresses in cycles, suiting small to medium capacities and systems that need very low evaporating temperatures (down to -50°C).

Are NH3 refrigeration compressors dangerous?

NH3 is toxic above 25 ppm (33 mg/m³) and flammable at 15% – 28% concentration in air, according to OSHA. However, an NH3 system designed to standard, fitted with automatic leak detection and operated by properly trained staff is safe in industrial use. Most large seafood plants in Vietnam use NH3.

What compressor capacity does a 1,000-tonne cold store need?

A 1,000 MT frozen store at -20°C in Vietnam (average ambient 35°C) needs a cooling load of roughly 120 kW to 180 kW (34 RT to 51 RT), depending on the insulation, how often goods move in and out, and the type of product stored. Tan Long calculates the real cooling load for each project before selecting a compressor model.

How many years does a screw compressor last?

An industrial NH3 screw compressor maintained on schedule lasts 20 to 30 years. Main bearing life is around 40,000 running hours (about 5 years running 24/7), after which they are replaced at overhaul.

Request advice and a quotation

Tan Long designs and builds industrial refrigeration equipment at its plant in Duc Hoa 1 Industrial Park, Tay Ninh (formerly Long An), so capacity and dimensions can be adjusted to the actual site. Call 0933 357 058 (Mr. Thinh) or send a quotation request with your output per shift and your main product type.