Draught Equipment and System Configuarations > Equipment and Configurations for Long-Draw Draught Systems > Cooling

As with direct-draw systems, kegs reside in a walk-in cooler held at 34° to 38°F. But to keep beer cold throughout its journey from keg to faucet requires additional cooling components that surround the beer lines themselves.  We find two common designs: air-cooled and glycol-cooled.

Trunk Line

In a forced-air long-draw system, beer lines travel through a tube or chase kept cold by a continuously operating recirculation fan.  The fan pushes cold air from a condensing unit inside the cooler into and through the ductwork. In both single-duct and double-duct systems cold air travels a route from the cooler to and through the tap tower as well as a return route back to the cooler. Single-duct systems use a tube-in-tube design effective for runs of up to 15 ft.  Runs of up to 25 ft. can be created using double-duct systems where separate tubes carry the outbound and return flows.

Glycol-cooled systems service runs longer than 25 ft. Here, a separate chiller pumps cold food-grade liquid propylene glycol through cooling lines parallel to and in contact with the beer lines.  These systems require well-insulated and carefully configured trunk line (See photo).  Each beer line (usually barrier line) in a trunk touches a glycol line to keep the beer cold as it travels from keg to the faucet.

Glycol Chiller

In addition to the glycol chiller used to maintain temperature of the beer lines, some systems use a separate glycol cooling system to chill the tap tower.

Typical Lond-Draw Glycol System

Typical Long-Draw Glycol System