active chilled beam system

Active Chilled Beam (ACB) System

250 South Wacker uses this revolutionary new HVAC system to transfer a large portion of the cooling and heating load from the less efficient primary air distribution system (fans and ductwork) to the more efficient water distribution system (pumps and piping).

With the ACB system, a central fan partially tempers building air as is done with conventional HVAC systems. This air is continuously supplied to the ACB units, but at a much lower pressure than with conventional HVAC systems. As a result, room air is induced into the unit and through the water coils. The induced room air is cooled or heated by the water coil in the unit, mixed with the air from the central system and returned to the room.

The central system is designed to circulate only the amount of air needed for ventilation purposes, while with the ACB units provide the necessary air movement and heating or cooling. This system reduces the amount of air circulated by the central system by 65%, and places the bulk of the air tempering load on the more efficient water distribution system.

Benefits of the ACB

1. Lower energy consumption and operating costs. Studies have shown that—in typical North American commercial office buildings—fan energy is often second only to lighting in terms of energy consumption. The active chilled beam system dramatically reduces the the fan energy needed because the system requires only a small amount of fan-forced air to be circulated at very low pressure. It is estimated that energy consumed heating or cooling 250 S. Wacker will be 77% less than it might be with a conventional VAV system.

2. Improved comfort through excellent air movement and uniform air temperatures throughout the room. With the ACB system, draftiness or "dumping" are not as much of a concern as with VAV or CAV systems. Because tempered air is diffused, rather than forced, into the space, it moves more steadily and evenly through the room.

3. Excellent indoor air quality and odor control. as the full ventilation air requirements are delivered to the zones at all times and at all load conditions. Superior humidity control at all sensible load conditions is also assured as the constant volume primary air is delivered with the proper moisture content to satisfy the latent loads.

4. Very low noise levels. The new technology nozzles used to induce air from the central system to the ACB units are whisper quiet. There is no terminal unit fan or motor in or near the occupied spaces.

5. Space savings. The ACB units at 250 South Wacker are installed in the ceiling allowing the tenant free and clear planning and access to the building’s windowall.

Learn about 250 South Wacker's Low-e Glass

Learn about 250 South Wacker's Eco-friendly finishes

For more information about active chilled beam systems, visit www.activechilledbeam.com