Absorption refrigeration

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absorption refrigeration diagramAt Warehouse Appliance, we have spent years educating homeowners on the benefits of gas refrigerators, but how do they work? They work on the principle of absorption refrigeration, but first, we need to define what absorption refrigeration means.

Simply put, absorption refrigeration “absorbs” the heat inside the fridge.
Removing the heat makes the air inside the fridge cold. The absorption unit or “Cooling Unit” is located in the back of the fridge in a sealed box which contains an array of steel pipes.

Both propane and natural gas are commonly used in absorption refrigerators.
The gas is used to heat the absorption unit. The heat produced by the gas, which is located at the bottom of the unit, activates a chemical mixture inside the cooling unit. When hot, this mixture changes from a liquid into a vapor and begins moving to the top of the unit in the same way coffee is made in a percolator.

Once at the top of the unit, the chemical mixture – which is now ammonia vapor – condenses into liquid ammonia. Now in the liquid state, the ammonia begins pouring down the steel pipes. The pipes, which are in a zig-zag pattern, go through the freezer compart where the liquid ammonia begins absorbing the heat.

Because it is at the top of the refrigerator, the liquid ammonia absorbs the heat in the freezer compartment first and continues flowing down to the fridge. If the ammonia has not reached its maximum absorption in the freezer it will continue to absorb heat from the refrigerator as it moves down the pipes. This process is the reason the freezer cools down before the lower part of the refrigerator.

Now you know the basics of absorption refrigeration. If you have questions about gas refrigerators or freezers for your home or cabin, call Warehouse Appliance at 928-636-1955.