Refrigeration Industry and 3D printing - Bio-based FDM desiccant wheel promises low-temperature humidity control for HVAC and refrigeration

A research team has designed, printed and bench-tested a rotary desiccant wheel made from commercial PLA/wood composite filament, aiming to reduce regeneration temperatures and cut energy use in building dehumidification and refrigeration air-treatment stages (Martínez-Sánchez 2025).

What was built

The project reports a component-scale wheel fabricated via material-extrusion (FDM) using pine-wood-filled PLA segments arranged into a honeycomb rotor and hub assembly. By tuning nozzle diameter, layer height and infill, the team targeted porosity control to raise vapour uptake without sacrificing printability or assembly tolerances (Martínez-Sánchez 2024; Martínez-Sánchez 2025).

• Material: off-the-shelf wood-PLA (pine) grades; higher wood content delivered higher moisture sorption in screening.
• Geometry: channelled honeycomb elements printed as repeatable modules for rotor build-up.
• Print parameters: smaller nozzle (≈0.4 mm) and larger layer height (≈0.3 mm) increased porosity and water-vapour adsorption; infill values of 30–60 % shaped airflow and pressure drop (Martínez-Sánchez 2024).

How it performed

In laboratory air-handling tests, the printed desiccant elements were exposed to controlled temperature, humidity ratio and flow representative of HVAC duty cycles. The study links adsorption gains to measured porosity (strong linear correlation) and demonstrates assembly-level operation of a printed wheel built from these modules (Martínez-Sánchez 2025; Martínez-Sánchez 2024).

• Porosity–uptake link: higher porosity correlated with higher vapour uptake (R²≈0.93), enabling parameter-driven tuning rather than new chemistry (Martínez-Sánchez 2024).
• Low-temperature regeneration potential: recent literature cited by the authors indicates effective desorption below ~60 °C for emerging polymer/composite desiccants—substantially lower than the ~80–140 °C often used for silica-gel wheels (Xue 2024; Socci 2025).

Engineering caveats: PLA’s glass-transition (~60–65 °C) caps continuous thermal exposure; designs must manage mechanical integrity and creep under cyclic wetting/heating. Nonetheless, segmental construction simplifies replacement and incremental upgrades (Martínez-Sánchez 2024).

Why it matters for refrigeration/HVAC

Supermarkets, cold-rooms and mixed-use facilities wrestle with latent load control. High humidity elevates compressor lift, drives coil icing, and degrades display-case performance. A bio-based, 3D-printed wheel that adsorbs at room temperature and regenerates with low-grade heat (e.g., condenser waste heat, solar thermal, or heat-pump discharge) could:

• Trim energy consumption by shifting part of moisture removal away from the vapour-compression cycle.
• Stabilise store humidity, improving case efficiency and reducing defrost frequency.
• Accelerate iteration: FDM enables rapid redesign of channels and porosity to balance adsorption, pressure drop and manufacturability (Martínez-Sánchez 2025; Comino 2023).

Compared with conventional wheels that embed silica gel or molecular sieves on fibre substrates, a wood-PLA substrate offers a bio-based bill-of-materials, short lead times from digital models, and on-site printability for bespoke sizes. While peak capacity may trail mineral sorbents, system-level gains from lower regeneration temperatures and faster design cycles can offset material limits in targeted applications (Martínez-Sánchez 2024; Socci 2025).

What’s next

The authors frame a pragmatic path to deployment (Martínez-Sánchez 2025):

• Duty-specific parameter maps linking nozzle/layer/infill to uptake and pressure drop for supermarket and cold-room AHUs.
• Hybrid architectures: pairing printed desiccant segments with indirect evaporative or heat-pump-assisted schemes to harvest waste heat for regeneration.
• Durability studies: cycling to characterise hydrolysis and mechanical drift in wood-PLA under humid, warm conditions, and evaluating coatings or material blends to extend life.

The bio-based FDM wheel does not displace high-capacity silica or MOF composites overnight, but it establishes a credible, low-temperature, rapidly manufacturable pathway for humidity control in refrigeration/HVAC—one that can be tuned on the printer, not just in the chemistry (Martínez-Sánchez 2025; Martínez-Sánchez 2024).