OFF-GRID REFRIGERATOR

One of the most basic needs in life is to keep food in adequate conditions, and for that a refrigerator is needed. In this project two types of refrigeration units (vertical one door refrigerator and a horizontal freezer) will be developed. The refrigeration units outer shells are based on low-cost efficient AC refrigerators available in the market (at least A+ energy class) and we will make the necessary modifications (inclusion of PCM -Phase Changing materials, salt water in our case, and fittings to allow flexible load control, a variable speed compressor, a smart controller to manage the “on-time” or charge time). The refrigerator prototypes will have additional fixtures, such as ability to handle voltage spikes (thunderstorms which are very frequent in Africa), smart-sensing to detect insulating leaks and to control the cabinet temperature and a smart controller to manage the entire system (PV solar photovoltaic system with storage, variable speed compressor and PCM freezing and melting cycles). The PCM containers will be built using 3D printing technology specially designed for each refrigerator. To promote social inclusion our prototype will have special add-ons for people with disabilities, allowing them to reach every item inside the horizontal freezer. A metallized thin film non-condensation mirror will be installed on the inside cover door and a special picking handle will be included. The main purpose of the project is to develop affordable super-efficient refrigerators/freezers for off-grid systems, powered by solar PV system and the charging periods for battery and PCM will be managed by a smart controller developed in the project. Both prototypes will be tested in a controlled environment chamber to simulate the conditions (temperature and humidity) off most African countries.