Heatless Desiccant Air Dryers
A trusted heatless desiccant air dryer manufacturer and supplier in China, delivering reliable, energy-efficient solutions for industrial compressed air systems.
Heatless desiccant air dryers are industrial dryers designed to remove moisture from compressed air or gas streams using high-efficiency desiccant materials. Our dryers operate without external heat, relying on a portion of dried compressed air (purge air) to regenerate the desiccant.
This simplifies the system, reduces maintenance, and eliminates the need for electricity or steam during regeneration. Heatless air dryers are ideal for applications requiring moderate dew points (-20°C to -40°C), continuous operation, and reliable drying performance.
Lingyu’s heatless desiccant dryers protect critical equipment, reduce system downtime, and maintain overall efficiency, making them suitable for industries such as electronics, petrochemicals, food processing, and pharmaceuticals. Explore our range below and request a quote today.
It uses high-performance pneumatic valves, good adsorbent materials, and electronic controllers, which are simple to operate, have low operating noise, and have long service life.
Stable outlet dew point
Minimum regeneration gas consumption
Long service life of adsorbent
Easy maintenance
High safety
High reliability
Adjustable regeneration gas consumption
Optional dew point monitoring and control system
Stable outlet dew point
Minimum regeneration gas consumption
Long service life of adsorbent
Easy maintenance
High safety
High reliability
Adjustable regeneration gas consumption
Optional dew point monitoring and control system
Heatless desiccant air dryers remove water vapor from compressed air through Pressure Swing Adsorption (PSA). Unlike heated regeneration dryers, they use a portion of the dried compressed air to regenerate the desiccant without an external heater or blower.
Lingyu CH and HH Series heatless desiccant air dryers provide an average purge air consumption of 8–14% and are designed for industrial applications requiring low pressure dew points with a simple twin-tower regeneration system.
They are commonly used for instrument air, pneumatic controls, electronics, chemical processing, precision manufacturing, and other moisture-sensitive compressed air applications.
A heatless dryer uses two desiccant towers that alternate between drying and regeneration.
Adsorption: Wet compressed air passes through one tower, where the desiccant adsorbs water vapor and dry compressed air flows downstream.
Regeneration: A portion of the dry compressed air is expanded to near atmospheric pressure and passed through the second tower. This purge air removes the moisture previously adsorbed by the desiccant.
Repressurization & Switching: Before the towers switch, the regenerated vessel is repressurized and pressure is equalized between the two towers. The cycle then repeats automatically to provide continuous dry compressed air.
No external heat is required during regeneration.
| Parameter | CH Series | HH Series |
|---|---|---|
| Drying principle | Pressure Swing Adsorption (PSA) | Pressure Swing Adsorption (PSA) |
| Capacity | 3.8–150 m³/min | 1.5–130 m³/min |
| Approx. capacity | 134–5,297 CFM | 53–4,591 CFM |
| Rated inlet pressure | 0.7 MPa | 0.7 MPa |
| Operating pressure | 0.6–1.0 MPa | 0.6–1.0 MPa |
| Rated inlet temperature | 10–30°C | 10–30°C |
| Maximum inlet temperature | ≤40°C | ≤40°C |
| Average purge air | 8–14% | 8–14% |
| Pressure dew point | -50°C to -20°C | ≤-40°C |
| Desiccant | Activated alumina | Activated alumina + high-performance molecular sieve |
| Rated ambient temperature | 35°C | 35°C |
| Ambient operating range | 2–45°C | 2–45°C |
Other working pressures and capacities above the standard range can be configured according to project requirements.
Heatless dryers require very little electrical power for regeneration because no heater or blower is used. However, part of the dried compressed air is consumed as purge air.
The Lingyu CH and HH Series specify an average purge air consumption of 8–14%.
For example, for a dryer processing 100 m³/min:
| Average Purge Rate | Approx. Purge Air |
| 8% | 8 m³/min |
| 10% | 10 m³/min |
| 12% | 12 m³/min |
| 14% | 14 m³/min |
This purge air has already been compressed, so it represents an indirect energy cost at the air compressor.
For smaller systems or applications where simplicity is the priority, heatless regeneration can be an economical solution. For larger systems operating continuously, the cost of purge air should be compared with the heater or blower energy required by other regeneration technologies.
| Factor | Heatless | Externally Heated |
| Regeneration method | Dry compressed purge air | Heater + purge air |
| External heater | No | Yes |
| Average purge air* | 8–14% | 4–8% |
| Regeneration electrical demand | Very low | Higher |
| System complexity | Lower | Higher |
| Maintenance | Simpler | Heater system also requires maintenance |
| Initial investment | Generally lower | Generally higher |
| Main operating cost | Compressed air loss | Heater power + reduced purge air |
| Typical selection | Small / medium or simple systems | Medium / large continuous systems |
*Based on Lingyu CH / HH technical data for the corresponding heatless and externally heated series.
Neither technology is automatically more energy-efficient in every application. The correct choice depends on airflow, annual operating hours, compressor efficiency, electricity cost, required PDP, and maintenance requirements.
Key selection parameters include:
For applications requiring a PDP within approximately -50°C to -20°C, select the appropriate CH Series configuration according to the required air quality.
For applications requiring ≤-40°C PDP, the HH Series uses activated alumina combined with high-performance molecular sieve.
For high-flow systems operating continuously, purge air consumption should also be included in the selection calculation.
Lingyu CH and HH Series specify an average purge air consumption of 8–14% under the applicable operating conditions.
The CH Series specifies a pressure dew point range of -50°C to -20°C. The HH Series is designed for ≤-40°C PDP.
No. Heatless regeneration uses a portion of the dried compressed air to regenerate the desiccant, so no external regeneration heater is required.
The CH Series uses activated alumina. The HH Series uses activated alumina combined with high-performance molecular sieve.
Heatless dryers use more compressed air for regeneration but do not require heater power. Externally heated dryers use an external heater to reduce purge air consumption. The better choice depends on system size, operating hours, and energy costs.
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