How many of us have ever given any consideration to the spacing behind the cooking appliances and the rear of the hood?

According to Don Fisher, President/CEO of Fisher-Nickel and Manager of the PG&E Food Service Technology Center, recent tests and experiments have shown that empty space behind cooking appliances can actually push the thermal plume forward.

With many exhaust hoods designed to maintain only the minimum 6” overhang, this means that the thermal plume (grease particles, volatile organic compounds, smoke and vapor from cooking) can actually be pushed forward enough to escape the front edge of the exhaust hood.

We already know as designers and operators that electric cords, plugs and gas lines normally create a space of 4” to 6” behind the cooking appliances. The desire on the part of many designers, chefs and operators to line up the fronts of all or many appliances can increase that empty space to many more inches behind various pieces. Testing has shown that this empty space at the rear of the appliance encourages a movement of the thermal plume forward.

Experiments have proven that when the space is closed off, the thermal plume then returns to the back wall of the cooking line and is readily captured.

In a recent conversation UP YOUR STACK™ had with FCSI Consultant, Dave Stewart based in Madison, Wisconsin, he suggested an idea that he employs. Dave adds a removable angled piece of stainless steel across the back of the hood just above the electric outlets and below the working level of the equipment. The purpose is to present a clean look, hide the plugs and outlets and reduce cleaning in this area. Now it looks like Dave may have added another reason by improving the exhaust ventilation process.

More information will be available from Don Fisher in the future about this subject but we wanted to give you a “heads up” about something most of us have most likely never even thought about.