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.
Furnace Plenum. A plenum is a compartment, air space or chamber that is filled with air that is then distributed elsewhere. A furnace plenum then, is such an air chamber that gets filled directly (and quickly) by a large blower that is above, below or adjacent to it. Air ducts connected to a furnace or heater plenum carry this air to various registers around a house or building.