Desiccant Solutions for the AC Industry
In early Automotive AC system, Silica Gel, a common desiccant was used. It was replaced by Molecular Sieve for several reasons:
- Molecular Sieve minimizes de-composure of refrigerants – compatibility
- Molecular Sieve has a higher water capacity under changing temperature and pressure. It will not release moisture back into the system.
- Molecular Sieve adsorbs water, but not refrigerant or oil
Criteria for Selecting the right Molecular Sieve in the Automotive AC system
- Chemical Compatibility – The molecular sieve should not cause de-composure of the refrigerant or formation of acids.
- High Water Capacity – The higher the capacity, the less molecular sieve is required.
- Good Physical Strength – The molecular sieve should not "break apart" because of vehicle vibration.
AD-1® Molecular Sieve
Flow Dry® Technology AD-1® molecular sieve adsorbent was created in response to a strong market need for a high quality, high performing, yet economical desiccant for drying HFC-134a and other refrigerants. With the same if not better quality and performance than other suppliers the AD-1® molecular sieve has been specifically developed as the economic desiccant alternative to meeting your high standards for:
- High water capacity - The desiccant’s purpose is to remove moisture from the refrigerant. AD-1® molecular sieve delivers the same drying performance that users have come to expect.
- Strong resistance to attrition (wet and dry) - System vibration has always been an issue in refrigerant systems. Vibration can cause molecular sieve beads to move or rub against each other. This can cause dust to form from bead attrition, which can then cause premature system failure due to plugging, or excessive component wear. AD-1® molecular sieve meets and exceeds the industry standards for attrition resistance. It is important to have excellent attrition resistance when the beads are dry – early in the system life, and when wet – as the system ages and the desiccant has adsorbed more moisture.
- High bead crush strength - High bead crush strength signifies a durable product that can withstand the rigors of the dryer assembly process and the end use application. AD-1® desiccant exceeds industry expectations with superior bead crush strength.
- Density - Most dryers have a defined, but limited volume available for the desiccant. AD-1® desiccant’s density utilizes the right amount of space in a dryer.
- Chemical compatibility - AD-1® molecular sieve has proven chemically compatible with HFC-134a. Discuss other refrigerant applications with your Flow Dry representative.
AD-1® Molecular Sieve 8x12 BeadsDesigned for use in Automotive Air Conditioning Systems
|Water Capacity @ 25 ℃ (wt% minimum)||18.0%||18.0%||ADT-1|
|Loss on Ignition (LOI) @ 960 (wt% maximum)||1.0%||1.0%||ADT-2|
|Bulk Density (minimum)||53.0 lbs/ft3||0.848 g/mL||ADT-3|
|Crush, average 25 beads (minimum)||14.0 lbf||62.0 N||ADT-4|
|Hydrated Attrition (wt% maximum)||2.0 %||2.0 %||ADT-6|
Bead Size Distribution (wt%)*
Through 6 mesh
Through 8 mesh
Through 12 mesh
Through 20 mesh
* Tolerance +/- 10%
100.0 %, min
90.0 %, min
10.0 %, max
100.0 %, min
90.0 %, min
10.0 %, max
0.01 %, max
Bead Sizes Available
AD-1® molecular sieve standard bead size is 8x12 mesh (2mm). Other bead sizes may be made available.
AD-1® molecular sieve production is rigorously tested, using advanced testing equipment and methods, for strict compliance to industry standards.
Safety and Handling
Contact us for a copy of the AD-1® molecular sieve MSDS and for any questions related to handling the product.