Hot air travels through the tubes and boxes of the patented PAR-2 and PAR-3 heat exchangers giving up its heat energy to the metal. Air temperature entering the tube is over 3000° F. Exiting the fryer, temperature is 500° F. The metal has absorbed the heat and transferred it to the shortening.

An important design feature of the PAR-3 heat exchanger is the strategic use of baffles in several locations. The agitator baffles are different from standard baffles as these have multiple ports and deflectors to swirl the hot air in all directions, which increases the efficiency of the heat exchanger.

The air temperature inside the PAR-3 heat exchanger changes dramatically from the flame in the beginning to the exiting air. The outer walls of the heat exchanger are much more uniform in temperature. The heat exchanger in turn heats the shortening. Because the temperature is very uniform throughout the vat, the result is perfectly cooked food. Most users discover that food cooks faster in the PAR-3 vat. Exposed to shortening a shorter period of time, food absorbs less shortening, resulting in better tasting food. It is common for users to save on shortening usage since less is absorbed in the food, less must be added back to the vat.