Hybrid liquid desiccant mechanical fan system for simultaneous indoor cooling and dehumidification

Background

The field of heating, ventilation, and air conditioning (HVAC) is driven by the need to maintain human thermal comfort, which relies heavily on the body’s ability to cool itself through sweat evaporation. While effective in dry climates, this physiological mechanism fails in humid environments where the air is already moisture-saturated. Elevated indoor humidity severely impairs natural cooling, negatively impacting occupant comfort, health, and productivity. Consequently, there is a critical need for effective indoor moisture removal. In most climates, managing this latent heat load requires far more energy than simple temperature control.

Despite this need, current dehumidification approaches suffer from significant drawbacks. Traditional air conditioning removes moisture by cooling air below its dew point to force condensation. This over-cooling is highly energy-intensive and frequently requires wasteful reheating before the air enters the room. Alternative technologies also fall short; solid desiccant wheels demand substantial thermal energy for regeneration. Meanwhile, existing liquid desiccant systems present severe operational hazards. They typically utilize highly corrosive chemicals that rapidly degrade building equipment. Furthermore, these conventional liquid setups carry a high risk of desiccant crossover, where harmful chemical droplets can escape into the supply air stream and contaminate the indoor breathing environment.

Technology

This cooling technology integrates a liquid desiccant dehumidification system directly into mechanical fan blades to deliver simultaneous convective and evaporative cooling. A non-corrosive, siloxane-based desiccant is pumped through embedded channels featuring a hydrophilic non-porous membrane. As the fan rotates, high-velocity airflow enhances mass transfer. The membrane selectively absorbs water vapor from the air while strictly preventing desiccant leakage. The moisture-laden fluid is then circulated to a central hub or external unit, where it is regenerated using low-grade heat sources, such as solar or waste heat.

This solution is highly differentiated because it overcomes the primary drawbacks of traditional HVAC and existing desiccant systems. Conventional dehumidification relies on energy-intensive condensation that cools air below the dew point. Standard liquid desiccants are often corrosive and risk contaminating the air stream. In contrast, this system’s unique combination of a siloxane-based fluid and a non-porous membrane eliminates corrosion and crossover risks. By merging mechanical airflow with chemical moisture removal, the technology enables independent control of air velocity and humidity. This effectively manages latent heat loads, allowing for higher temperature setpoints and significantly lower energy consumption.

Benefits

• Significantly reduces energy consumption by managing moisture and latent heat loads without relying on traditional, energy-intensive condensation methods.
• Enhances indoor thermal comfort by providing simultaneous convective and evaporative cooling, allowing for independent control of air velocity and humidity.
• Ensures clean, uncontaminated airflow by using a non-porous hydrophilic membrane that strictly prevents the non-corrosive liquid desiccant from crossing over into the supply air.
• Supports sustainable and eco-friendly operation by utilizing low-grade, renewable, or waste heat sources (such as solar energy) to regenerate the desiccant.
• Lowers overall operational costs through reduced pumping requirements and lower regeneration temperatures compared to conventional HVAC and desiccant systems.
• Offers highly flexible implementation, capable of operating as a standalone in-room device or integrating into centralized building ductwork for residential, commercial, or industrial use.

Applications

• Commercial office space cooling
• Industrial warehouse humidity control
• Residential room air conditioning
• Green building HVAC integration
• Humid climate indoor cooling

Additional info

This system integrates siloxane-based liquid desiccant into mechanical fan blades via hydrophilic non-porous membranes. Rotation generates high-velocity airflow, facilitating mass transfer as the membrane selectively absorbs water vapor. This enables simultaneous convective and evaporative cooling, managing latent heat loads without energy-intensive condensation. The desiccant is regenerated using solar or waste heat, allowing for independent control of humidity and air velocity in indoor environments.