[Daox]

I just did a little googling myself. Here is an interesting solar dehumidifier. I think they call it "solar" but in order to make it solar you'd have to have solar hot water. The hot water is used to regenerate the descicant. Their PDF manual has a lot of info on the unit.

Solar Dehumidifier

HOW IT WORKS
The DH3000 effectively removes moisture at normal temperatures without the freeze-up
problems inherent with refrigerant dehumidifiers and/or conventional air conditioners. This
enables the unit to maintain lower relative humidity and to dry deeper, thereby having a
more significant effect on carpets, floors, walls, contents, and structural materials. This
capability also inhibits mold and mildew growth caused by moist or humid conditions.

The “heart” of the DH3000 is the desiccant wheel (see wheel specs). The detail in Fig. 1
shows that the wheel is made with a series of air passages or channels. Air can be forced
through these channels in either direction.



Figure 1
The desiccant wheel is made entirely of a desiccant/fiber material. Desiccants are
extraordinary substances, having a high capacity for moisture adsorption, while being
easily regenerated. When damp air passes through the desiccant wheel, it adsorbs the
moisture into the desiccant material within the wheel and dries the air. Conversely, when
desiccants are heated (also called regeneration), they release the moisture and become
regenerated.

The DH3000 utilizes two air streams through the wheel to complete this cycle: the Process
Air Stream and the Regeneration Air Stream. Again, Figure 1 illustrates how the cycle
works.

In the Process Air Stream, damp air is drawn through the channels in the wheel where the
desiccant absorbs most of the moisture in the air. This air, now “dried out”, is then
supplied back into the area being dehumidified. As the DH3000 operates, the wheel turns
very slowly so that a new portion of it is always in the drying zone.
The Regeneration Air Stream is heated by the hot water coil and forced through the wheel 8
at the drying zone. This hot air now causes the desiccants to release the moisture in a
vapor form. The moisture is exhausted through the Regeneration Air Outlet. This moist
air, also called “Exhaust Air”, is then vented to the outside. At this point, the wheel has
been reactivated and the dehumidification cycle is complete.

The Regeneration Air Stream should always be vented to the outside. Process Air Supply
may be discharged directly back into the space or ducted to the supply of the air
conditioner.

Review of the process:
• Dry air or process air is returned to the room or to the area being dehumidified.
• As the wheel turns; the “wet” area rotates through the drying zone and is exposed to
the heated regeneration air stream.
• Moisture in the desiccant is released into the regeneration air stream.
• The regeneration air, with the moisture, is vented to the outside.