Background:
In a desiccant dehumidifier, the regeneration air refers to the process of removing moisture from the desiccant material so that it can continue absorbing moisture from the air effectively.
Desiccant dehumidifiers work by using a desiccant material (such as silica gel or zeolite) to absorb moisture from the air. As the desiccant absorbs moisture, it becomes saturated and needs to be regenerated or dried out to continue the dehumidification process.
During the regeneration process, a portion of the dry air, often referred to as the regeneration air, is diverted from the environment or processed air stream and directed over the saturated desiccant material. This dry air absorbs the moisture from the desiccant, allowing it to release the captured moisture and return to its dry state, ready to absorb more moisture from the incoming air.
The moisture-laden air generated during this regeneration process is usually expelled or vented outside the dehumidifier or the controlled environment, preventing it from affecting the indoor air quality.
By using this method of regenerating the desiccant material with dry air, the dehumidifier can continuously remove moisture from the incoming air, maintaining a lower humidity level in the desired space.
Figure 1: Average Cycle for Desiccant Dehumidifier Regeneration
For our design we have decided to implement a refrigeration cycle for the method of cooling regeneration as opposed to an air to air heat exchanger or no cooling in general. The regeneration air will flow into the evaporator from the desiccant drum. This will cool the air and cause the water to then condense. The heat produced from the condenser is used to aid in heating the air entering the desiccant drum.
Figure 2: Model Showing Vapor Compression Cooling Cycle
Future Steps:
We have decided to source a refrigeration cycle as most condensers and evaporators are large and expensive. This approach is the most cost effective way to acquire the parts required is to take parts from an off shelf dehumidifier. From our analysis we intend on using the Ninesky Dehumidifier as it will fulfill our needs. It can be seen in Figure 3 below.
Figure 3: Ninesky Dehumidifier