Direct-Fired Make-Up Air Systems
In a small setting such as a typical home’s hood over the kitchen range, the air can be made up by normal ventilation, air leaks or an open window. In a commercial or industrial operation, however, the large amount of air being evacuated by an exhaust blower must be replaced directly by a make-up air system to maintain the air quality in the building.
An exhaust system in restaurants and food service operations will pull a tremendous amount of air from the cooking areas. A building’s normal ventilation system won’t replace the air fast enough. Instead, more air will rush through air leaks, bringing in unheated or uncooled air from the outside. With buildings becoming more energy efficient with those leaks being filled, the air will have to come from other sources, including backdrafts down chimneys or through water-heater flues, replacing the air with carbon monoxide.
In industrial buildings, exhaust systems from manufacturing processes can be immense. Without a make-up air system, the air that can be pulled in from any available source can be as fouled as the air it replaces, even containing volatile gases.
A make-up air system blows fresh air into the building whenever the exhaust system powers up. Direct-fired make-up air systems are widely used in kitchen and food service operations, industrial processing, paint booths, and wastewater treatment.
These systems not only provide clean, fresh air to replace the fouled exhaust air, direct-fired make-up systems will also heat or cool the air it sends in to maintain comfort levels for the people inside the building.