All habitable spaces include ventilation. From day one the space has a perfect balance of exhaust versus intake providing a neutral building pressure that meets the appropriate codes. Over time it is inevitable that changes are made to the building’s ventilation to keep up with the changes to the building.
A restaurant has an increase in customers and needs another grill, a manufacturer needs additional production and adds another line, a school adds a field house. Most common in commercial, industrial and institutional spaces, including office buildings, restaurants, warehouses, manufacturing facilities, etc., the common approach is to add another exhaust fan.
The exhaust fan will remove the additional heat, smoke, smell, etc. What is not considered is where the air to satisfy the additional exhaust load is going to come from.
The imbalance in building pressure has 5 major negative effects impacting: