Step 1 Identify a suitable location for your fridge. It does not matter whether it is under the sunshine or a shade. What is most important is that you choose a location where you do not have to shift the fridge from place to place – this is a permanent structure.
Step 2 Determine the size of you fridge that you want to construct. Also read: steps to follow while investing in drip irrigation
Step 3 Erect a double wire mesh boundary with at least a sizeable width within.
Step 4 Pack large charcoal particles in between while filling the gaps with smaller charcoal particles. Avoid use of charcoal dust because it will pollute your food.
Step 5 For the base, use mud; and for the roof, use dry grass. Do not use wire mesh or charcoal for the base or roof construction.
Step 6 Do not forget to put a door to keep away animals and thieves.
Step 7 Also, you have to be mindful that you have to pour water on this charcoal to maintain the cool temperatures within. You can either do this manually or automatically using constructed structures similar to those used in Drip Irrigation. The pouring of water can be done continuously or at a time depending on weather condition outside. The higher the temperatures, the more the water required.
An interesting concept I came across was one used by farmers in western Uganda. Their fridges are much smaller both in width, length and height. These women farmers place a bucket full of water on top of the “fridge”; hanging from the bucket onto the charcoal edges are deep thick wicks (like those of a lantern). The logic is that the wicks suck water and drip it on the charcoal, thereby cooling it.
Charcoal is used as it is a good coolant. Wet charcoal does not allow easy passage of heat thus resulting into low temperature inside. Also, use of water on the charcoal is to minimize charcoal dust. Charcoal is made of wood which by nature do not transmit heat easily. Also, charcoal has pore spaces which absorb and store water inside, this reduces heat passing from outside.
On the other hand, because charcoal comes from trees, use of charcoal only contributes to environmental degradation; which is disastrous to our environment. It grossly affects the climatic condition of an area, as well as the soil. It is important therefore that you seek legal country permission and guidance before you undertake this project. Also, you can start an active tree planting campaign.
Compiled by Karamagi Akiiki Ednah