Abstract: Disclosed is a climate chamber, such as a refrigeration chamber, with a conveyor apparatus. The conveyor apparatus includes an endless, partially collapsible conveyor belt having a product-supporting bed with an upstanding sidewall along one edge of the belt. The belt is coiled in a generally helical configuration to form a plurality of helical tiers stacked one above the other, so that the sidewall portions form a substantially continuous wall-like surface, with the top portion of a wall of an underlying tier contacting an adjacent superior tier so as to form a generally self-supporting edge region of the conveyor belt. The other edge of the conveyor belt is supported by a generally helical guide rail, which maintains adjacent tiers of the helical stack spaced apart from one another. Air flow through the stack can be freely circulated between the spaced other edges of adjacent tiers and/or vertically through the perforated conveyor belt.