For students and those new to the industry, it is the big stainless steel box over cooking equipment. However, to those of us in the industry, it might be a canopy, a ventilator or simply a hood. And often the names are used interchangeably. No matter what they are called, they all are designed to remove smoke, grease and other particles from the space were the cooking is taking place. They are also equipped with a fire safety system that is designed to trigger in the event a fire breaks out. That could mean a fire developing in a deep fat fryer or fire igniting behind the filters or in the duct system.

So do not get confused by what the box is called. While most are connected to the fan via a duct that travels through the building up to the roof, a few exhaust out of a building side wall. Another small group for special applications and limited use, utilize a set of built-in multi-stage filters that cleanses the grease-laden air and may release it back into the building. These operate only over electric appliances and have limited capacity.

For a fuller explanation of terms and applications, go to www.upyourstack.com and visit the Design Tips tab under Resources for the article on Type I vs. Type II hoods.