Design an adsorption refrigerator capable of maintaining a temperature between 2°C and 8°C that utilizes passive solar energy and can be built in developing countries. The team’s final product will be a clear and comprehensive set of instructions for building the device.
Based on the design decision matrices, a solar-powered adsorption refrigerator was selected for the design of the vaccine refrigerator. This refrigerator has no moving parts aside from a few valves. It uses no toxic materials, generally available materials, and should be simple to build and operate. The refrigerator has an intermittent cycle. It will “charge” during the day and remove heat from a cooling volume at night.Some previously used adsorbent/refrigerant pairs used for solar adsorption refrigeration systems are zeolite and water, silica gel and water, activated carbon and methanol, activated carbon and ammonia, and activated carbon and ethanol. It has been determined that the performance of each pair depends greatly on the climate in which it is tested.
- Macropores (>500 Angstrom*)
- Transitional Pores (20–500 Angstrom)
- Micropores (0–20 Angstrom)
“Charcoal is an ideal material for refrigeration because it has pores, which absorb and store water. This reduces heat from outside. And because wet charcoal does not allow easy passage of heat, it results in low temperatures inside the cubicle.”