Introduction

The use of water especially drinking water is needed everywhere around the world, especially in places where rainwater and rivers/lakes are not in abundance. In this work, we develop a Solar Powered Moisture Harvester, that allows for the transformation of water vapors that are present everywhere, into clean water. The system is divided into 2 compartments, first is the salt compartment and the second is the water collection compartment. Five design iterations are done each with progressive improvements. The final design comprises of a system of condensation chamber with salt for moisture capture, a peltier heater/cooler to distill the water and solar panel/battery system for driving the peltier device. In addition to this, a slant roof to ensure more efficient moisture capture, along with strategic positioning of the hoses and utilization of mini pump suction power and also their vibrations that encourage droplet sliding in to collection chamber.

Final Design

There are several section of the final design (see pictures in the gallery) 

#1 Peltier System; With an operational voltage of 9V and a current of 2A, the peltier system heats up or cools the salt and condensation chambers respectively. This device generates a temperature gradient on each of its side where one gets hot and the other gets cold when given electricity. The system is divided into 3 sections, top, middle, and bottom. The top section is where the hot side heat sink is located at, this heat sink is to release as much heat from the peltier as soon as possible. The middle section is where the peltier is located at, and it is surrounded by epoxy (unlikely to melt) which keeps the system intact. Finally, the bottom section is where the cold side heat sink is located at.

#2 Pump; With an operational voltage of 5V and a current of 0.09 A, the pump pumps both moist air and water that is collected from the salt compartment to the condensation chamber. In addition to this, the vibrations from the pump is also used to encourage a faster rate at which the droplets fall.

#3 Condensation Chamber; There will be the main access and the secondary access for droplets to enter the condensation chamber. The main access placed right in the bottom middle of the harvester’s slanted roof. Inside the chamber, on both sides of the tube, lips are found in order to guide the droplet flow to the tube. The secondary access is placed right in the top middle of the harvester’s slanted roof. This is due to the results during testing which indicate that some droplets at the top instantly drop down without sliding. Inside the chamber, on both sides of the tube, lips are found in order to guide the droplet flow to the tube.

Conclusion

1. Further research on distillation technologies with low power consumption are still needed.

2. Potential finding of optimal vibration used in encouraging droplet movements will help significantly.

3. Ideal operation of the system is to identify the pulses of heating and pumping since droplet formations are a slow process and as much power is wanted to be saved.

4. PLA and Silicone surfaces have difficulty in forming droplets.