What role does temperature play in solar still functionality?

Temperature and Evaporation Rates

Temperature significantly affects the evaporation rate in a solar still. For every 10°C (18°F) increase in temperature, the evaporation rate doubles. A temperature of 35°C (95°F) or higher is ideal for optimal evaporation. In a typical solar still design, the water is heated by the sun’s radiation, and the temperature of the water increases as it absorbs the heat. This increased temperature turns the water into vapor, which is then collected as condensation on the underside of the still’s cover.

Maximizing Temperature Gain

To maximize temperature gain, it’s essential to orient the solar still towards the sun and ensure minimal shading. A clear, transparent cover is also crucial to allow maximum solar radiation to reach the water. Additionally, a black or dark-colored water reservoir can absorb more solar radiation, increasing the water temperature. By maximizing temperature gain, the evaporation rate increases, resulting in faster water purification and collection.

Temperature and Condensation

As the water vapor rises and cools, it condenses on the underside of the still’s cover. A temperature difference of at least 10°C (18°F) between the water and the cover is necessary for efficient condensation. The condensed water then drips or flows into a collection container, where it can be stored or used. By controlling the temperature and ensuring adequate condensation, a solar still can efficiently purify and collect water, even in arid or water-scarce environments.