The Sun Bowl, created by Constantine Orfan, is a simple system of bowls and a pot designed to be used for water purification. According to Orfan, under ideal conditions, the Sun Bowl has the capacity to pasteurize up to 12-quarts of contaminated water per day. To use the tool, you place the steel bowl in the sunlight, place your water pot in the center of the bowl and cover the pot with the clear plastic punch bowl. Water typically must reach a temperature of above 150°F for approximately one hour to kill harmful waterborne bacteria and virus. It is always important to monitor the water temperature with a thermometer or WAPI, water pasteurization instrument.
The Sun Bowl works because the large mixing bowl acts like a deep parabolic reflector that collects and focuses sunlight in the center of the bowl where you place your water pot. The black color of the pot acts like a light magnet absorbing all available light striking its' surface. The pots' metal molecules are excited by the photons that make up the light resulting in heat which is transferred to the water (or food) in the pot. Finally, The clear plastic bowl helps to retain heat by promoting a greenhouse effect and preventing heat loss due to wind and air temperature. Because of the round shape of the bowl, no additional turning is required to catch the available sunlight as the sun moves across the sky during the day. Some sunlight is always being focused on the water pot no matter what the angle or position of the sun in the sky.
Though intended for water purification, the unit could also be used for solar cooking.