Refrigerant Molecular Sieve (XH Series)

Key Takeaways:

• Series Overview: XH Series refrigerant molecular sieves are zeolite desiccants purpose-built for moisture control in refrigeration and AC systems, with four specialized grades — XH-5, XH-7, XH-9, and XH-11 — each optimized for different refrigerant families.
• XH-7 (Workhorse Grade): Potassium-calcium-based XH-7 with ≈3Å pores is the industry standard for R134a systems, delivering excellent selectivity, high crush strength (≥70 N/bead), and proven compatibility with most HFC/HCFC/HFO refrigerants.
• XH-9 (Universal Grade): XH-9 offers the broadest refrigerant compatibility in the series, making it the preferred choice for mixed-refrigerant fleets, service operations, and multi-refrigerant manufacturing environments.
• System-Level Protection: Both XH-7 and XH-9 achieve residual moisture below 10 ppm, preventing ice blockages, acid formation, and corrosion in compressors, expansion valves, and heat exchangers.
• Full Range Available: XH-5 covers legacy CFC/HCFC systems and XH-11 serves next-generation high-pressure refrigerants (R410A, R32, R407c), completing a comprehensive product lineup for every refrigerant application.

What Are XH Series Refrigerant Molecular Sieves?

XH Series refrigerant molecular sieves are high-performance aluminosilicate desiccants specifically engineered for deep moisture removal in refrigeration and air conditioning systems. Installed in liquid line filter driers, XH Series sieves work alongside particulate filters to remove both moisture and solid contaminants, safeguarding critical system components from the damage caused by moisture ingress.

XH Series is chemically and structurally distinct from standard 3A and 4A molecular sieve used in general industrial drying — the pore size falls in a similar ~3Å class, but the formulation is engineered specifically for stable long-term contact with refrigerants and lubricant oils, an environment standard-grade molecular sieve is not qualified for. 4A in particular should never be used in refrigerant circuits under any circumstances.

The series is anchored by two flagship grades: XH-7 and XH-9. XH-7 is the industry workhorse — the most widely used grade for R134a and general HFC/HCFC/HFO systems, with a ≈3Å pore structure that selectively captures water while excluding R134a molecules. XH-9 is the universal grade, engineered for the broadest refrigerant compatibility range in the series, making it ideal for mixed-refrigerant environments — the key difference from XH-7 is refrigerant compatibility breadth, not pore size or bead specifications.

Complementing these two main grades, XH-5 serves as the basic option for legacy CFC/HCFC systems (R12, R22), and XH-11 is the specialized grade for next-generation high-pressure refrigerants including R410A, R32, and R407c. All grades share core advantages: low attrition rates (≤0.1% wt), high crushing strength, chemical inertness with standard lubricants, and deep drying performance that silica gel and activated alumina cannot match.

For readers who want a deeper look at the working principles and refrigerant-type compatibility across the series, see our Refrigerant Molecular Sieve Guide.

XH-7 vs XH-9: Key Differences

Understanding the distinctions between XH-7 and XH-9 helps you select the right grade for your application.

• Chemical Base: XH-7 uses a documented potassium-calcium dual-cation framework; XH-9's exact cation composition is proprietary/not independently documented in public sources — both are aluminosilicate zeolite formulations
• Pore Diameter: Both grades are ≈3Å class; no authoritative public data documents a systematic pore-size difference between XH-7 and XH-9 — the real distinguishing factor is refrigerant compatibility breadth (see below), not pore size
• Primary Use Case: XH-7 is the standard for R134a systems and household/commercial refrigeration; XH-9 is the universal grade for mixed-refrigerant fleets and service operations
• Refrigerant Compatibility: XH-7 covers R134a, R12, R1234yf plus most HFC/HCFC/HFO types; XH-9 adds R500 series, R600a, and a wider range of blended refrigerants (excludes difluoromethane mixtures)
• Bulk Density: XH-7 ranges 0.75–0.82 g/cm³; XH-9 ranges 0.80–0.90 g/cm³
• Crush Strength: Both grades ≥70 N per bead — no verified public data shows a systematic difference between XH-7 and XH-9 on this metric
• Water Adsorption: XH-7 ≥17% wt; XH-9 ≥16–17% wt
• Loss on Ignition: XH-7 ≤1.2%; XH-9 ≤1.5%
• Color: XH-7 is white beads; XH-9 is white to light tan beads

Key Benefits

Deep and Selective Moisture Removal

• XH-7's ≈3Å pore structure selectively adsorbs water molecules (≈2.8Å) while excluding R134a and other refrigerant molecules from entering the zeolite framework
• XH-9's universal formulation delivers strong water adsorption while maintaining inertness across the widest refrigerant compatibility range in the XH Series
• Both grades achieve residual moisture below 10 ppm in properly sized systems, preventing ice formation and acid buildup
• Optimized pore distribution enables fast adsorption kinetics for quick system commissioning

High Mechanical Durability

• Both XH-7 and XH-9 deliver ≥70 N per bead crush strength, resisting bed compaction and pellet fracture under high-pressure cycling in transport and industrial applications
• Attrition rate of ≤0.1% wt across both grades minimizes dust generation and downstream contamination
• High bulk density maximizes desiccant mass per unit volume, extending replacement intervals

Broad Chemical Compatibility

• XH-7 is inert to R134a, R12, R1234yf, and most HFC, HCFC, and HFO refrigerants
• XH-9 is compatible with nearly all refrigerants including R12, R22, R134a, R404a, R500 series, R600a, and R1234yf (excludes R32 and R32-containing blends such as R410A/R407C)
• All XH Series grades are compatible with POE, PVE, mineral oil, and AB oil lubricants without co-adsorption of refrigerant or additive molecules
• Stable pH range of 8–10 prevents chemical breakdown and preserves system composition

Long Service Life and Reliability

• Typical service life of 3–5 years in properly maintained systems with correctly sized filter driers
• Withstands temperature and pressure cycling without significant degradation in adsorption performance
• Low dust and attrition characteristics maintain clean system operation throughout the desiccant's service window
• Max operating temperature of 400°C ensures stability under peak thermal conditions

Comprehensive System Protection

• Prevents ice blockages at expansion valves and capillary tubes by maintaining moisture below critical thresholds
• Inhibits acid formation caused by moisture-reactive refrigerant decomposition, protecting compressor windings and bearing surfaces
• Reduces corrosion of copper, steel, and aluminum components throughout the refrigerant circuit
• Extends overall system service life and lowers maintenance and warranty costs

Applications

Household & Commercial Refrigeration XH-7 is the standard desiccant for household and commercial refrigerators and freezers using R134a systems. Installed in liquid line filter driers, it removes moisture from the refrigerant circuit to prevent ice formation at expansion valves, inhibit acid corrosion, and maintain efficient cooling performance throughout the equipment's service life. XH-9 is preferred when the same production line manufactures systems using multiple refrigerant types.

Mixed-Refrigerant Service Fleets and HVAC Contractors XH-9's universal compatibility makes it the top choice for service companies and contractors working across a wide range of refrigerant types including R12, R22, R134a, R404a, R500 series, and R600a (excluding R32-containing blends such as R410A/R407C, which require XH-11). One desiccant grade covers nearly all common refrigerants, simplifying inventory and ensuring correct grade selection on every job.

Automotive Air Conditioning Automotive AC systems endure severe operating conditions — high vibration, wide temperature swings, and frequent thermal cycling. XH-7 molecular sieve in receiver driers delivers reliable moisture removal with ≥70 N crush strength resisting mechanical breakdown, compatible with R134a and R1234yf automotive refrigerants. For multi-brand fleets running different refrigerant types, XH-9 offers universal coverage.

Commercial HVAC & Supermarket Systems Supermarkets, grocery stores, and food service operations depend on XH Series molecular sieves to maintain reliable operation of display cases, walk-in coolers, and freezer systems. XH-7 handles standard R134a and HFC installations, while XH-9 serves facilities with mixed refrigerant types or those using R500-series blended refrigerants. The high bulk density handles larger refrigerant charges and longer piping runs typical in commercial installations.

Transport Refrigeration Refrigerated trucks, shipping containers, and rail cars face extreme vibration, temperature variation, and harsh road conditions. The high mechanical strength and low attrition rate of both XH-7 and XH-9 make them ideal for transport refrigeration. XH-7 is standard for dedicated R134a transport units, while XH-9 is preferred for multi-temperature fleets with diverse refrigerant requirements.

Heat Pump Systems Heat pumps require desiccant that performs effectively in both heating and cooling modes. XH-7 molecular sieve in bi-flow filter driers ensures consistent moisture removal regardless of refrigerant flow direction, maintaining system efficiency year-round. XH-9 provides the same bi-flow capability with broader refrigerant compatibility.

Legacy CFC/HCFC Systems (XH-5) XH-5 is the basic-grade desiccant formulated for legacy R12 and R22 systems, providing reliable moisture removal for traditional CFC and HCFC refrigerants with stable chemical properties.

Next-Generation High-Pressure Systems (XH-11) XH-11 is the specialized grade for next-generation high-pressure refrigerants including R410A, R32, R407c, R452a, R452b, and R454b, delivering optimized performance for systems running these newer refrigerant types.

XH Series Grade Selection Guide

Select by Refrigerant Type

• XH-7 (Most Common): Best for R134a, R12, and R1234yf systems; also compatible with R404a, R22, R600a, R290, HFCs, HCFCs, HFOs, and CO₂ (excludes R32 and R32-containing blends such as R410A/R407C)
• XH-9 (Universal Choice): Preferred for mixed-refrigerant environments, R500 series blends, R600a hydrocarbon systems, and service fleets handling multiple refrigerant types; compatible with nearly all refrigerants except difluoromethane-containing mixtures
• XH-5 (Basic Grade): For legacy R12 and R22 CFC/HCFC systems
• XH-11 (Next-Gen): For R410A, R32, R407c, R452a, R452b, R454b, and other high-pressure next-generation refrigerants

Select by Application Type

• Household refrigerators / commercial freezers on R134a → XH-7
• Automotive AC on R134a or R1234yf → XH-7
• HVAC contractor / service fleet with mixed refrigerants → XH-9
• Manufacturing with multiple refrigerant lines → XH-9
• Supermarket systems on R500-series blends → XH-9
• Legacy R12/R22 equipment → XH-5
• VRF or high-pressure AC on R410A/R32 → XH-11

Bead Size Selection

• Φ1.6–2.5 mm beads: Standard size for most filter drier applications; good balance of adsorption kinetics and pressure drop
• 3–5 mm beads: Larger beads for higher flow rates and lower pressure drop; suitable for large industrial systems

Quantity Sizing The amount of molecular sieve required depends on total refrigerant charge size, expected moisture ingress rate, desired service life, and system type. Always follow equipment manufacturer recommendations for filter drier sizing and replacement intervals.

Using an incorrect grade may cause co-adsorption of refrigerant molecules or additives, altering system chemistry. Always verify compatibility with your specific refrigerant before installation. For grade selection assistance, contact our technical team.

Regeneration

XH Series molecular sieves can, in principle, be thermally regenerated by heating under vacuum or dry purge gas to drive off adsorbed moisture, similar to other zeolite-type desiccants. Typical thermal regeneration range for XH-7 and XH-9 is 175–260°C — lower than general-purpose 4A/5A molecular sieve (200–320°C) — since the dual-cation formulations may contain adsorbed olefin-type compounds that can polymerize at elevated temperatures.

However, for molecular sieve already installed inside a sealed filter drier, on-site regeneration is generally not recommended: the risk of releasing previously adsorbed moisture or contaminants back into the refrigerant circuit outweighs the cost savings, and most filter drier housings are not designed to be reopened and resealed reliably.

For bulk-supplied desiccant intended for reuse in open systems or manufacturing processes (rather than sealed filter driers), regeneration parameters should be confirmed against your specific equipment and application before implementation. For most refrigeration and air conditioning service work, replacing the filter drier or desiccant core is the recommended and standard industry approach.

Packaging & Shipping

We offer flexible packaging and shipping options to suit your project scale and logistics requirements.

Standard Packaging:

• 25 kg drums (moisture-proof, suitable for trial orders and small batches)
• 150 kg steel drums (standard bulk packaging for industrial orders)
• 500 kg super sacks (most popular for industrial bulk orders)
• 1000 kg jumbo bags (for large-scale projects)
• Custom packaging available on request, including pre-charged filter drier cores for direct installation

Minimum Order Quantity (MOQ):

• 1 ton (entry-level orders accepted — perfect for first-time customers)
• 5+ tons (standard bulk orders)
• Container-level supply for long-term partnerships

Container Loading Capacity:

• 20'GP container: 18-20 tons (palletized)
• 40'GP container: 22-24 tons (palletized)
• 40'HQ container: 24-26 tons

Loading Ports: We ship from major Chinese ports based on your requirements: Shanghai, Qingdao, Tianjin, Ningbo, and Shenzhen.

Lead Time:

• Stock orders: 7-15 days from payment confirmation
• Made-to-order: 20-30 days

Shipping Terms: FOB / CIF / CFR / EXW — flexible based on your destination and preferences.

Documents & Certificates

We provide complete documentation for every order:

📄 Technical Data Sheet (TDS) — Confirmed with you during product selection, ensuring exact specifications match your application requirements.

📄 Safety Data Sheet (SDS) — Provided before shipment, meeting all international transportation and handling standards.

📄 Certificate of Analysis (COA) — Issued for each production batch, delivered with your shipment for full quality traceability.

Additional documents available on request: Certificate of Origin (COO), Packing List, Commercial Invoice, Third-party Inspection Report (SGS / BV), Form E (for Middle East destinations with applicable tariff benefits).

Frequently Asked Questions

Q: What is the difference between XH-7 and XH-9 molecular sieve? A: XH-7 is potassium-calcium-based with ≈3Å pores, optimized for R134a and most HFC/HCFC/HFO systems. XH-9 shares the same ~3Å pore class but offers the broadest refrigerant compatibility in the series, including R500 series blends and R600a — the real difference is refrigerant compatibility breadth, not pore size. Choose XH-7 for dedicated R134a systems and XH-9 for mixed-refrigerant environments.

Q: What refrigerants is XH-7 molecular sieve compatible with? A: XH-7 is primarily designed for R134a systems and is also compatible with R12, R1234yf, and most HFC/HCFC/HFO refrigerants including R404a, R22, and R600a. It is not suitable for R32 or R32-containing blends (R410A, R407C) — see XH-11 for those. For specialized refrigerant applications, please verify compatibility with our technical team.

Q: What refrigerants is XH-9 molecular sieve compatible with? A: XH-9 is a universal-grade desiccant compatible with nearly all refrigerants including R12, R22, R134a, R404a, R500 series, R600a, and R1234yf. It is not recommended for R32 or refrigerant blends containing difluoromethane (R32), such as R410A and R407C — those require XH-11 grade.

Q: Can I use XH-7 for R410A or R32 systems? A: While XH-7 has broad compatibility, R410A and R32 systems typically require XH-11 grade for optimal performance. XH-11 is specifically formulated for high-pressure next-generation refrigerants. Please contact us for grade recommendation.

Q: Should I choose XH-7 or XH-9 for my refrigeration systems? A: If your systems run primarily on R134a or a narrow range of HFC/HCFC refrigerants, XH-7 is the standard and most cost-effective choice. If you service or manufacture systems using multiple refrigerant types including blended refrigerants (R404a, R500 series) or hydrocarbons (R600a), XH-9's universal compatibility will simplify your inventory and ensure correct grade selection.

Q: How often should I replace the filter drier in my refrigeration system? A: For properly maintained, leak-tight systems, filter driers typically last 3-5 years. They should always be replaced whenever the system is opened for service, after a compressor burnout, or if moisture contamination is detected.

Q: What is the difference between XH-5, XH-7, XH-9, and XH-11? A: XH-5 is for legacy R12/R22 systems; XH-7 is the typical grade for R134a and general HFC/HCFC systems; XH-9 is a universal grade for nearly all refrigerants; XH-11 is specialized for R410A, R32, and R407c. Contact us for grade selection guidance.

Q: Is XH Series molecular sieve compatible with CO₂ (R744) refrigeration systems? A: XH-7 is chemically compatible with CO₂, but CO₂ systems operate at much higher pressures (up to 150+ bar) and may require specialized formulations or different particle sizes. Always verify the specific product is rated for CO₂ applications.

Q: How do I know if my system has a moisture problem? A: Common signs include ice or frost at the expansion valve or filter drier outlet, reduced cooling capacity, fluctuating suction and discharge pressures, elevated discharge temperatures, and oil discoloration. A moisture indicator sight glass gives a quick visual check; laboratory oil analysis is the most accurate method.

Q: What's the difference between refrigerant molecular sieve and regular industrial molecular sieve? A: Refrigerant-grade molecular sieve is specifically formulated and tested for compatibility with refrigerants and lubricants, with tighter quality control for dust generation, chemical inertness, and adsorption performance under refrigeration operating conditions.

Need Other XH Series Grades or Custom Specifications?

We supply the full XH Series including XH-5, XH-7, XH-9, and XH-11 for diverse refrigerant applications. For bulk pricing, grade recommendation, or custom specifications such as specialized bead sizes, pellet forms, or pre-charged filter drier cores, please send your refrigerant type, lubricant type & system charge size to us. Our technical team will get back to you within 24 hours with a tailored solution.

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