R290 Refrigerant

R290 Refrigerant: Why It Matters for Under-Sink Water Chillers

Author: [2026-09-10] | By Xiamen Smart Water Technology Co., Ltd. Allen Huang allen@kitchenwatertap.com

R290 is propane (C₃H₈), structural formula: CH3CH2CH3, a natural hydrocarbon refrigerant with ODP 0 and a very low GWP of about 3. For compact under-sink water chillers, its combination of heat-transfer performance, low environmental impact and high cooling efficiency makes it a strong alternative to higher-GWP refrigerants.

Xiamen Smart Water Technology uses environmentally preferable R600a or R290 refrigerants in its water chiller range. New-generation chiller development is moving toward R290, with the aim of improving cooling performance while maintaining a low-GWP refrigerant platform.

R290 is the refrigerant designation for propane. It contains no chlorine and therefore has zero ozone depletion potential.

Its thermodynamic properties are particularly useful in compact refrigeration equipment where heat exchanger size, compressor load, cooling recovery and cabinet volume all affect the final product.

Values can vary slightly by reference standard, purity and measurement conditions. Final equipment specifications should therefore be based on the refrigerant manufacturer's technical data and the applicable product standard.

The choice of refrigerant directly affects the compressor, condenser, evaporator, expansion device, heat exchanger and control strategy.

R290 has several characteristics that can benefit a compact under sink water chiller.

High Heat-Transfer Potential and Refrigeration Capacity

R290 has favorable thermodynamic characteristics, including high latent heat of vaporization and good thermal conductivity. This allows a properly engineered refrigeration circuit to transfer heat efficiently.

The practical result is not simply a smaller compressor. The complete refrigeration circuit must be matched around:

• Compressor displacement
• Evaporating temperature
• Condensing temperature
• Capillary tube or expansion device
• Heat-exchanger geometry
• Refrigerant charge
• Water inlet temperature
• Target chilled-water temperature
• Ambient temperature

A claim such as "R290 saves 30% energy" should therefore never be treated as a universal equipment specification. Actual energy consumption depends on the complete system design and test conditions.

The main engineering trade-off is clear: R290 performs well, but it is highly flammable.

R290 is classified as A3, meaning high flammability and lower toxicity within the ASHRAE refrigerant safety classification system.

For an under-counter appliance installed inside a kitchen cabinet, this changes the engineering requirements.

A responsible R290 chiller design needs to consider:

• Refrigerant charge limitation
• Refrigeration-circuit integrity
• Component compatibility
• Ignition-source control
• Electrical component placement
• Ventilation requirements
• Leak-risk assessment
• Service procedures
• Applicable flammable-refrigerant standards
• Product installation environment

Because R290 is heavier than air, leaked refrigerant can accumulate in low areas. The appliance enclosure, electrical architecture and ventilation strategy therefore need to be evaluated as one system.

For mass production, the relevant safety requirements depend on the destination market and appliance category. The factory should identify the applicable standard before finalizing the refrigeration architecture rather than treating certification as a post-production paperwork exercise.

R600a and R290 are both natural hydrocarbon refrigerants with very low GWP and zero ODP. They are not interchangeable without redesigning the refrigeration circuit.

Differences in boiling point, pressure characteristics, volumetric capacity, and system requirements affect compressor selection and heat-exchanger design.

The choice should be made from the complete refrigeration-system design, not from GWP alone.

Xiamen Smart Water Technology currently uses R600a or R290 across its water-chiller development. New products are being developed around R290 where its thermodynamic performance and target application make it appropriate.

European refrigerant regulation is increasingly driving equipment manufacturers away from high-GWP fluorinated gases.

The EU F-gas Regulation (EU) 2024/573 establishes restrictions on the placing on the market and use of certain fluorinated greenhouse gases. The exact restriction depends on equipment type, capacity, refrigerant and application.

This creates an important distinction for buyers:

• Low GWP does not automatically mean the entire appliance is compliant.
• A compliant product still requires assessment of:
• Refrigerant type
• Refrigerant charge
• Appliance category
• Electrical safety
• Flammability requirements
• Construction
• Leakage protection
• Labelling
• Installation instructions
• Market-specific conformity assessment

For an importer or kitchen-appliance brand, the correct approach is to request model-specific compliance documentation rather than relying only on a refrigerant declaration.

Request R290 Chiller Specifications & Compliance Documents

A refrigerant alone does not determine chilled-water performance.

A typical compact water chiller follows this thermal path:

Water inlet → water heat exchanger → refrigeration evaporator → chilled-water outlet

At the refrigeration side:

Compressor → condenser → expansion device → evaporator → compressor

The evaporator extracts heat from the incoming drinking water. The chiller controller then monitors temperature and compressor operation to maintain the specified chilled-water range.

For a chilled water tap, the chiller must also be matched to the faucet's flow requirement.

For example, if the tap is expected to dispense 1.5 L/min of chilled water, the refrigeration system must have sufficient cooling capacity to maintain the specified outlet temperature at the stated inlet-water and ambient conditions.

Cooling Capacity Cannot Be Evaluated by Tank Size Alone

A larger cold-water reservoir does not automatically mean better cooling.

The engineering variables include:

This is particularly important for chiller sparkling water taps, because carbonation performance also depends strongly on water temperature.

CO₂ dissolves more effectively in cold water than in warm water. Therefore, a chiller sparkling water system normally cools the filtered water before carbonation.

The functional sequence is:

Filtration → Chilling → Carbonation → Dispensing

The refrigeration system must provide enough cooling capacity to maintain the required water temperature under actual dispensing conditions.

For a product developer, the target specification should therefore state:

• Water inlet temperature
• Chilled-water outlet temperature
• Flow rate
• Ambient temperature
• Recovery time
• Refrigerant type
• Refrigerant charge
• Compressor model
• Rated electrical input
• Refrigeration capacity

Without these conditions, two suppliers can quote apparently similar "3°C water chillers" while delivering very different real-world performance.

For an R290 water chiller manufacturer, factory testing needs to cover both refrigeration performance and flammable-refrigerant safety.

A production inspection plan may include:

The exact test limits should be established from the approved product design and applicable destination-market standards.

A production line using 100% functional testing provides a stronger quality-control basis than relying only on sample inspection.

Submit Your Chiller Performance Requirements

For an international drinking-water brand, changing refrigerant is not simply a component substitution.

An ODM engineering team needs to reassess the refrigeration platform because R290 can require different:

• Compressor specifications
• Refrigerant charge
• Expansion-device sizing
• Tubing configuration
• Heat-exchanger design
• Electrical-component arrangement
• Safety controls
• Production procedures
• Service instructions
• Certification documentation

This is where inner waterway design and refrigeration engineering need to be considered together.

A compact under-sink drinking-water system may combine a filter, chiller, boiler, carbonation unit and multifunction faucet in one kitchen installation. Cabinet volume is limited, so thermal insulation, ventilation, component placement and waterway routing all affect the final product.

For a private-label project, the most useful engineering documents to exchange before sampling are:

• Target water temperature
• Required flow rate
• Ambient operating range
• Water inlet temperature
• Electrical voltage/frequency
• Refrigerant requirement
• Maximum allowable cabinet dimensions
• Target certifications
• Filter specification
• Faucet functions
• Carbonation requirement, if applicable
• Expected daily usage

The technical case for R290 is strongest when three requirements overlap:

Low GWP + efficient refrigeration + compact equipment design.

R290's GWP of approximately 3 is dramatically lower than many legacy HFC refrigerants, while its thermodynamic properties can support efficient compact refrigeration when the system is designed specifically around propane.

The trade-off is equally clear: R290 is A3 flammable, so charge limits, ignition-source control, refrigeration-circuit integrity and applicable safety standards must be built into the product from the first engineering stage.

For Xiamen Smart Water Technology, the development direction is therefore practical rather than simply regulatory: R290 is being adopted for new water-chiller platforms where its cooling performance, energy characteristics, environmental profile and safety architecture fit the application.

Before approving an under sink water chiller manufacturer, request the following technical data in writing:

This information allows engineering, purchasing and compliance teams to compare suppliers on the same technical basis.

For compact drinking-water refrigeration, R290 is a strong low-GWP refrigerant option when the refrigeration circuit and safety system are designed specifically for it.

Its approximately 3 GWP and zero ODP give it a clear environmental advantage, while its thermodynamic properties can support efficient cooling. The limitation is its A3 flammability, which makes refrigerant charge, component placement, leakage control and applicable safety standards part of the product architecture.

For an under-sink water chiller or chiller sparkling water tap, the correct supplier should therefore be evaluated on the complete system-not the refrigerant name alone.

Xiamen Smart Water Technology develops under-sink water chillers, chilled water taps, sparkling water systems, boiling water taps, multifunction drinking faucets and complete drinking-water systems for international brands and distribution programs.

For product development, send your target cooling temperature, flow rate, cabinet dimensions, electrical market and certification requirements. The refrigeration and waterway configuration can then be evaluated before tooling and mass production.

Is R290 refrigerant suitable for an under-sink water chiller?

Yes. R290 is well suited to compact refrigeration when the system is engineered for its A3 flammability classification, specified refrigerant charge and applicable safety requirements.

What is the GWP of R290 refrigerant?

R290 has a 100-year GWP of approximately 3 and an ODP of 0. These values make it a low-GWP alternative to many high-GWP fluorinated refrigerants.

Can an ODM factory develop an R290 chilled water tap system?

Yes. Xiamen Smart Water Technology develops R290/R600a water chillers and integrated drinking-water systems, including chilled water taps and sparkling-water configurations for international product programs.

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