Understanding Dehumidification Technology: Insights from ARBS 2024 and Humiscope

At ARBS 2024, my first stop was Humiscope, a company specializing in indoor climate control with a focus on dehumidification technology, including desiccant and refrigerant dehumidifiers. Despite having specified and inspected these systems in the past, I realized I lacked a deep understanding of their workings. John Morgan from Humiscope provided a comprehensive explanation, shedding light on the distinctions and applications of these technologies.

Refrigerant (Condensing) Dehumidifiers

John started by explaining refrigerant or condensing dehumidifiers, a technology I was somewhat familiar with. Using a simple psychrometric chart, he demonstrated that these systems are effective in environments generally above 10 degrees Celsius. The process involves cooling the air to remove moisture through condensation, similar to how air conditioners work. The air is then reheated using the condenser coil, which is an essential feature for maintaining desired indoor conditions.

These dehumidifiers primarily operate on an on-off control mechanism. However, advancements over the past decade have introduced remote condensers to avoid reheating in scenarios where moisture removal is needed without temperature increase. A critical limitation of refrigerant dehumidifiers is their tendency to ice up at zero degrees Celsius, preventing operation below this dew point.

Desiccant Dehumidifiers

Transitioning to desiccant dehumidifiers, John provided an in-depth explanation. This technology was new to me, and he used their TFT dehumidifier on display as a practical example. The system features a rotary section containing desiccant material, akin to silica gel packs used in various household products. As the desiccant material rotates, it absorbs moisture in one section and releases it in another, facilitated by a heating element.

John emphasized the precision of desiccant dehumidifiers, achieved through Solid State Relay (SSR) controls that allow for close proportional control. Unlike refrigerant dehumidifiers, desiccant systems are not constrained by freezing temperatures, making them ideal for conditions below six degrees Celsius. However, they do introduce additional heat into the environment, a factor that must be accounted for in system design.

Desiccant dehumidifiers effectively manage latent heat, providing relief to air conditioning coils struggling with latent loads. Typically, these systems only require 20-30% of the supply air to pass through the desiccant material to achieve efficient dehumidification.

Practical Applications and Design Considerations

Combining the two technologies can offer optimal solutions across a broader temperature range. For instance, desiccant dehumidifiers can handle lower temperatures and manage latent heat, while refrigerant dehumidifiers are suitable for higher temperatures and straightforward moisture removal without additional heat.

In just a brief interaction, my understanding of dehumidification technologies expanded significantly. The insights provided by John Morgan and the team at Humiscope have equipped me with the knowledge to make informed decisions about specifying and designing these systems in the future. For any further inquiries, I now know the experts to consult.

For more detailed information, visit Humiscope's official website.

Wes

B.eng Mech ( hons)