Refrigerant Molecular Sieve (XH Series)

Key Takeaways:

• Core Function: XH-7 is a potassium-calcium-based aluminosilicate desiccant engineered for deep moisture removal in R134a refrigeration and air conditioning systems, with proven compatibility across HFC, HCFC, and HFO refrigerant families.
• Selective Adsorption: With a pore diameter of ≈ 3Å (0.3 nm), XH-7 selectively adsorbs water molecules (kinetic diameter ≈ 2.8Å) while completely excluding R134a and other refrigerant molecules, preventing system contamination and chemical instability.
• Enhanced Mechanical Strength: Radial crush strength of ≥ 70 N per bead with bulk density of 0.75–0.82 g/cm³ ensures long-lasting structural integrity under high-pressure refrigeration cycles.
• Broad System Compatibility: Chemically inert with R134a, R12, R1234yf, and most HFC/HCFC/HFO refrigerants, as well as POE, PVE, mineral oil, and AB oil lubricants.
• System Protection: Achieves residual moisture below 10 ppm, preventing ice blockages, acid formation, and corrosion in compressors, expansion valves, and heat exchangers.

What Is XH-7 Refrigerant Molecular Sieve?

XH-7 is a high-performance potassium-calcium-based aluminosilicate desiccant specifically designed for moisture control in R134a refrigeration and air conditioning systems. The XH-7 formulation incorporates calcium as a co-exchange cation alongside potassium, producing a refined pore structure with a diameter of ≈ 3Å (0.3 nm). This tailored pore geometry selectively captures water molecules (kinetic diameter ≈ 2.8Å) while completely excluding R134a molecules and other refrigerant molecules, preventing adverse reactions and maintaining system chemistry stability.

The potassium-calcium dual-cation framework delivers multiple advantages over conventional formulations: higher crush strength (≥ 70 N per bead), lower dust generation (attrition rate ≤ 0.1% wt), tighter quality control (loss on ignition ≤ 1.2%), and a higher bulk density (0.75–0.82 g/cm³) that allows more desiccant mass per filter drier volume. These properties translate directly into longer service intervals, cleaner system operation, and improved reliability under demanding thermal and pressure cycling conditions.

XH-7 is chemically inert across R134a, R12, R1234yf, and most HFC/HCFC/HFO refrigerant families, as well as all standard lubricant types including POE, PVE, mineral oil, and AB oil. It achieves deep drying to residual moisture levels below 10 ppm — a performance level that silica gel and activated alumina cannot reach.

In the field, XH-7 molecular sieve is installed in liquid line filter driers, where it works alongside a particulate filter medium to remove both moisture and solid contaminants. This dual-action protection safeguards critical components — compressors, expansion valves, and heat exchangers — from the damage caused by moisture ingress.

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

XH Series Overview

The XH Series includes multiple grades optimized for different refrigerant families. XH-7 is our typical grade for R134a and general-purpose HFC/HCFC systems. Other grades in the series include:

• XH-5: Basic refrigerant desiccant for R12 and R22 systems. Suitable for legacy CFC and HCFC refrigerants with stable chemical properties.
• XH-9: Universal-grade desiccant compatible with nearly all refrigerants including R12, R22, R134a, R1234yf, R404a, R407c, R500 series, and R600a. Excludes mixtures containing difluoromethane.
• XH-11: Specialized desiccant for next-generation refrigerants including R407c, R410A, R32, R452a, R452b, R454b, and R500.

For applications requiring XH-5, XH-9, XH-11, or other customized grades, please contact our technical team for grade selection and bulk pricing.

Key Benefits

Superior Drying Performance

• Achieves residual moisture levels below 10 ppm, preventing ice formation and acid buildup in the refrigerant circuit
• Water adsorption capacity of ≥ 17% wt (25°C, RH 50%) ensures effective moisture capture even at low concentrations
• Significantly outperforms silica gel and activated alumina in deep drying applications
• Optimized pore distribution enables fast adsorption kinetics for quick system commissioning

Enhanced Mechanical Durability

• Radial crush strength of ≥ 70 N per bead resists bed compaction and pellet fracture under high-pressure cycling
• Bulk density of 0.75–0.82 g/cm³ provides more desiccant mass per unit volume, extending replacement intervals
• Attrition rate of ≤ 0.1% wt minimizes dust generation and downstream contamination
• Loss on ignition ≤ 1.2% confirms structural stability after high-temperature activation

Universal Chemical Compatibility

• Inert to R134a, R12, R1234yf, and most HFC (R32, R404a, R410a), HCFC (R22, R12), and HFO (1234YF) refrigerants
• Compatible with POE, PVE, mineral oil, and AB oil lubricants without co-adsorption of refrigerant or additive molecules
• Potassium-calcium-based formulation prevents chemical breakdown and preserves system composition over the full service life

Long Service Life

• High adsorption capacity combined with excellent mechanical stability delivers typical service life of 3–5 years in properly maintained systems
• 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

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 (R134a Systems)

XH-7 molecular sieve is the standard desiccant in 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.

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.

Commercial HVAC Systems

Supermarkets, grocery stores, and food service operations depend on XH-7 molecular sieve to maintain reliable operation of display cases, walk-in coolers, and freezer systems. The high bulk density (0.75–0.82 g/cm³) 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 (≥ 70 N per bead) and low attrition rate (≤ 0.1% wt) of XH-7 molecular sieve make it ideal for transport refrigeration applications.

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.

Industrial Cold Storage

Industrial cold storage facilities and freezer warehouses operate at extremely low temperatures where moisture control is mission-critical. XH-7 molecular sieve provides the deep drying necessary for reliable low-temperature operation, protecting compressors and expansion valves in HFC and HCFC refrigeration systems.

Selection Guide

Refrigerant Compatibility Selection

Always select the correct XH Series grade for your refrigerant type:

• XH-7 (this product): Best for R134a, R12, R1234yf systems — the typical choice for household and commercial refrigeration
• XH-5: For legacy R12 and R22 systems
• XH-9: Universal grade for mixed refrigerant applications (R12, R22, R134a, R404a, R500 series, R600a, etc.)
• XH-11: For next-generation refrigerants R407c, R410A, R32, R452a, R452b, R454b

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.

Bead Size Selection

• Φ1.6–2.5 mm beads: Standard size for most filter drier applications; good balance of adsorption kinetics and pressure drop

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.

Regeneration

XH-7 molecular sieve 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 is 175–260°C — lower than general-purpose 4A/5A molecular sieve (200–320°C) — since the potassium-calcium-based formulation 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 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 R32, R404a, R407c, R22, and R600a. For specialized refrigerant applications, please verify compatibility with our technical team.

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: 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-7 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?

We supply the full XH Series including XH-5, XH-9, and XH-11 for diverse refrigerant applications. For bulk pricing, grade recommendation, or custom specifications, 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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