Chicago's yearly precipitation comes in at an average of about 36 inches (910 mm), but during the summer, rain arises from short-lived hit-or-miss rain rather than actual prolonged rainfalls, and thunderstorms also occur with regularity at night. In a normal summer, temperatures exceed 90 Â°F (32 Â°C) on 23 days.
You might have heard someone mention flue spaces for rack storage, and wondered what flue spaces are and why they are needed. Flue spaces are clear lines of sight from the floor up to the ceiling within rack storage areas. There are two types of flue spaces - transverse flues and longitudinal flues.
A flue space's net width is a measure of its gross width minus any horizontal obstructions, such as rack uprights, located within the flue space. In other words, a rack upright (typically 3 in. [75 mm] wide) is not considered a flue space, due to the cross bracing used. If the space between two rack structures is more than 24 in. (600 mm), treat the space as an aisle for in-rack sprinkler design and installation purposes. Maintain vertical alignment of flue spaces as closely as possible.