Principles and Benefits of "Radiant" Passive Chilled Beams

Frenger's X-Wing chilled beam represents the very latest development in passive beam technology. X-Wing employs convective and "Radiant" cooling principles and is designed to deliver high cooling duties (up to 370 watts per meter) with no noise and minimal air movement.

As cold water passes through the chilled beam the warm room air is cooled against the beam's cooler surfaces. This cooled air, which is heavier due to its higher density, then streams through the punched louvres in the beam and percolates through the small ceiling perforations into the room space below. In this way air is circulated within the room, with warm air from the room being continually replaced by cooled air.

In addition to this convective cooling process, the cold surfaces of the beam also absorb heat radiation from the building occupants and the warmer surrounding surfaces. X-Wing's radiation quotient is approximately 40% of the total cooling effect (the other 60% of cooling being generated by the convective cooling effect described above). The ability of X-Wing to cool by radiation means that, when compared to a finned tube battery, X-Wing can deliver 40% more cooling without increased draught risk.

The efficiency of the convection process, coupled with the ability of the product to exchange energy by way of long-wave radiation, means that X-Wing retains a high cooling effect even when the air temperature in the room is relatively low (e.g. at night or when the building is unoccupied). In this way large amounts of cold energy can be stored in the building structure during low load periods, and used to offset heat gains when the need arise.