Infrared Fryers

One of the most widely used pieces of equipment in the food service industry is the deep-fat fryer. Perhaps the most significant advance in gas fryers, in terms of efficiency and economics, is the use of the infrared burner.

Standard Fryers

A standard fryer consists of a kettle containing cooking oil or fat, heated by thermostatically controlled burners or heating elements. In a conventional gas fryer, the burner flames are directed into immersion tubes running directly through the lower part of the kettle. The flames and hot combustion gases transfer heat as they pass through these immersion tubes, first to the tubes themselves and then, indirectly, to the oil that cooks the food. Unfortunately, the ratio of the heat produced to the heat potentially available in the fuel is approximately 47%. Utilizing infrared heat transfer improves the energy efficiency of the fryer to about 80%.

Infrared Fryers

While a conventional fryer utilizes the hot combustion gases to transfer heat to the kettle, the infrared fryer uses a radiant heat transfer process to heat the kettle directly without heating the surrounding air. Radiant energy only turns to thermal energy when it strikes an object, similar to the way the sun's energy can warm you even when the surrounding air is cold.

The typical infrared burner consists of a set of ceramic plates with approximately 200 holes per inch of surface. Natural gas and air flow through these holes, burning on the plate's surface at approximately 1,650°. This heat is transferred directly to the fry tank without heating the intervening air. Some infrared fryers have the burners placed flush against the sides of a V-shaped fry tank, shown by (A) in the illustration, while others suspend the infrared burners inside the cylinders near the bottom of the fry tank, shown by (B).


The primary benefit associated with the infrared fryer is increased energy efficiency, resulting in reduced operating costs. By increasing the energy efficiency from 47% for a conventional fryer to roughly 80%, the required gas input is substantially reduced. Where a 120,000 BTUH fryer was once necessary, an 80,000 BTUH infrared fryer may be sufficient to do the same job.

In addition, most infrared fryers are designed to have faster recovery times, thereby increasing production. Optional solid-state controls can also reduce temperature swings and extend the life of the cooking oil, one of the most significant expenses associates with fryers.

Other Advances in Frying Equipment

In addition to the infrared fryer, there are two other improvements to the conventional fryer: the catalytic fryer and the convection fryer. Both offer improved energy efficiency and reduced operating costs. The catalytic fryer uses an adaptation of the infrared burner to enhance heat transfer and minimize wasted heat. The convection fryer utilizes a pump to circulate the cooking oil through a heat exchanger and around the food being cooked. This eliminates temperature variations in the fry tank, speeds the cooking process and increases the energy efficiency of the unit to approximately 75%.