Free Piston Stirling Cooler
RIGID Stirling Cooler, unlike a compressor, is a cooling system that continuously repeats gas compression and adiabatic expansion using naturally occurring helium gas as a refrigerant. Helium is a very safe gas, completely harmless to our global environment. It is typically used in refrigerators, laboratory equipment, and vaccine storage for low-temperature distribution of goods. FPSC-Stirling engine technology is a breakthrough in Small and Deep Freezing. Temperature down to -120℃ in just a few minutes.
- RS40
- RS80
- RS100
- RS100 Plus
Cryocooler: State-of-the-Art Fast and Deep Freezing!
RIGID, one of the leading Chinese companies in terms of innovation, has developed a Free Piston Stirling Cooler – FPSC. The cooler brings the whole product to a new level, where it can save a lot of energy and greatly improve efficiency.
The FPSC cooler has several advantages over refrigerated compressor systems. They can achieve very low temperatures -86℃ (Max -160℃), have no moving parts except for the pistons, which reduces the risk of failure, and have a relatively high efficiency. They are used in a variety of applications, including Food, Cold chains, Laboratory Equipment, Automatic Devices, Petrochemicals & Oil, Scientific Research, Life Science, Medical Imaging, and the cooling of electronic components.
The RIGID Cryocooler is a cooling system that has only two moving parts. The cooler unit has a stainless steel housing and all sensitive components are hermetically sealed inside. This means it costs less to maintain. PFSC continuously repeats gas compression and adiabatic expansion, and uses natural helium gas as a refrigerant. Helium is a very safe gas. It is completely harmless to our environment.
Technical Data
- Specification
- Video
- Main Features
- Structure
- Application
Click picture below to watch the video!

Environmentally Friendly
RIGID Stirling Cooler adopts helium which is a naturally occurring gas that is harmless to the human body, does not deplete the ozone layer, and does not contribute to global warming.
Super Cooling Capacity
The FPSC can easily reach temperatures below -99℃ (on the cold head). This is extremely difficult to achieve with vapor compressors. The Stirling cryocooler is highly efficient. It can be up to 6 times higher than thermoelectric (Peltier) coolers.
Lightweight & Compact Size
Weight: 6~7 kgs (half the weight of compressor systems) The FPSC is suitable for use in life science, laboratory, medical, food, small countertop freezers, or portable refrigerators, as well as special low-temperature applications.
Precise Temp. Control
The FPSC is continuously modulated by electronic circuitry, not by on/off cycling as in compressor systems. The control circuits maintain a constant set temperature, allowing for extremely precise temperature control, ideal for sensitive applications.
Energy Savings
The RIGID FPSC consumes 40W~100W of power and is compatible with a variety of power sources such as 12V or 24V direct power, photovoltaic (solar cells), or in-house generators, as well as 110/220VAC power.
FPSC Stirling Model

Model: RS40
- Input power: 12V DC
- Working current: 6A
- Noise: ≤38dB
- Size: ODФ86mm x Length 260mm
-
Temp Range in Cold Fin (Cold part): -100℃~ 0℃
Model: RS80
- Input power: 24V DC
- Working current: 6A
- Noise: ≤48dB
- Size: ODФ86mm x Length 270mm
-
Temp Range in Cold Fin (Cold part): -120℃~ 0℃


Model: RS100
- Input power: 24V DC
- Working current: 6A
- Noise: ≤48dB
- External Size: 132×132x336mm(LxWxH)
-
Temp Range in Cold Fin (Cold part): -150℃~ 0℃
Model: RS100 Plus
- Input power: 24V DC
- Working current: 6A
- Noise: ≤48dB
- External Size: 167× 156 x 291mm (LxWxH)
-
Temp Range in Cold Fin (Cold part): -160℃~ 0℃

Advantage






Application
- Application Examples
- Working Process
Free Piston Stirling Coolers are complete CFC-free systems, using natural Helium gas. They are small, portable, and are widely used for precise temperature control for under -160℃ max. The default version of Stirling coolers includes pistons, heat exchangers, and compression spaces. But we see technological advancements in all industries, such as Biotech, Pharmaceutical, Food, Energy, Chemical, Medical, Bio-Science, logistics, and Metrology.
Isovolumetric Exothermic Process
Both pistons move in the same direction at the same time and the volume of gas remains constant until the compression piston reaches its dead center. As the gas passes through the regenerator, the heat is transferred to the packing, the temperature is reduced, and the pressure is also reduced.
Isothermal Compression
The compression piston moves while the expansion piston does not. Gas is isothermally compressed, compression heat is transferred through the cooler to the coolant (water or air), the temperature is maintained, pressure is increased, and volume is decreased.
Isothermal Expansion Process
The compression piston stops at the stop point while the expansion piston continues to move to the stop point. The gas is isothermally expanded and absorbs a certain amount of heat (cooling capacity) from the low-temperature heat source (cooling object) through the cold heat exchanger. The volume increases and the pressure decreases.
Constant Volume Heating Process
Both pistons move in the same direction at the same time to the stop point, the gas volume remains unchanged and returns to the starting position. As the gas passes through, it absorbs heat from the regenerator packing, and the temperature increases while the pressure increases.
Feature (3)
E-shop
Sample products are available from our online store. Your order will be proceeded in 24hrs and delivered by DHL/UPS/FedEx.

Free Piston Stirling Cooler Projects
Related Products (6)
FPSC is a kind of Stirling Cryocooler with a small footprint but efficient performance. RIGID Stirling cooler is a type of cryocooler that uses the Stirling cycle to achieve cooling. The Stirling cycle is a thermodynamic cycle that involves the compression and expansion of gas to produce a temperature difference. In a Stirling cryocooler, this cycle is used to produce a temperature difference between two regions, which can then be used to achieve cooling.
A Stirling cryocooler utilizes the Stirling cycle to convert electricity into the movement of heat from the cold tip towards the heat rejecter.
Stirling engines are energy conversion devices used as prime movers, refrigerating, or heat pumps. Currently, they are used commercially as cryogenic cooling systems, deep and fast freezing, and cold chain logistics, and are under development as low-noise, low-emission automotive engines.
Temperature down to -90℃ in a few mins. And with our largest model RS100, the maximum temperature can reach to minus -150℃.
Although air is the traditional working fluid for Stirling engines, Hydrogen and Helium are also employed for improved performance due to their better thermal properties.
The Cryocooler design life is 5 years, and this is the recommended lifetime, although the current mean time to failure (MTTF) is over 200,000 hours, roughly 23 years.
The cryocooler components are enclosed in a welded pressure vessel and there is no way to access them. There is no maintenance required on the cryocooler. We do recommend keeping the air fins free of debris on units that have cooling fins.
The cryocooler components are enclosed in a welded pressure vessel and there is no way to access them. There is no maintenance required on the cryocooler. We do recommend keeping the air fins free of debris on units that have cooling fins.
We have four models of Stirling Coolers:
- RS40:-100°C
- RS80:-120°C
- RS100:-150°C
- RS100 plus:-160°C
- RS40:12V DC
- RS80:24V DC
- RS100:24~30V DC
- RS100 plus:24~30V DC
You can purchase the cooler directly from our online shop.