Appreciation of the Application of Chilled Beams in Some Foreign Buildings

Working Principle of the Chilled Beam:
The active chilled beam system is an air conditioning system that integrates the functions of refrigeration, heating, and ventilation. It can provide a good indoor climate environment and control for individual zones. The primary air is mainly used to eliminate the indoor moisture load, and it can also provide heating, cooling, and ensure the supply of fresh air; the terminal heat exchange coil is used to handle the indoor heat/cold load. In summer, the treated primary air flow enters the chilled beam and then passes through the nozzles to the lower end of the chilled beam. According to the Venturi effect, when a high-speed air flow passes through an obstacle, the air pressure near the upper port on the leeward side of the obstacle is relatively low, thus generating an adsorption effect. The room air at the lower end of the chilled beam flows upward due to this effect and is cooled when passing through the heat exchanger. The cooled air mixes with the primary air flow, and the temperature is lower than the room temperature, and then it enters the room to cool the air there. Through such a repeated cycle, the heat in the room is carried away by the cooling coil, thus achieving the function of refrigeration.

In winter, hot water flows in the heat exchanger, so the chilled beam plays the role of heating.

The coil of the active chilled beam is generally equipped with a condensate water pan. Once the cold water temperature is lower than the dew point temperature and condensation occurs, the condensed water can be collected by the condensate water pan.
The passive chilled beam system is an air conditioning system that integrates the functions of refrigeration and heat exchange.

This system needs to operate in combination with an independent primary air system. The primary air is mainly used to eliminate the indoor moisture load and ensure the supply of fresh air. The terminal of the passive chilled beam relies on the principle of complete natural convection for refrigeration and heat exchange. The hot air flow rises and the cold air flow sinks, which will generate a circulating air flow in the room. This chilled beam system integrates the advantages of comfort, low noise, energy conservation, and low maintenance.
The air flowing out from the chilled beam will form two air flows in opposite directions, flowing along the suspended ceiling to both sides of the chilled beam. Such an air flow forms a very good indoor air distribution. The air flow flowing along the suspended ceiling forms the Coanda effect and thus flows along the ceiling and then slowly flows to the cooling area. Since there is no strong blowing from a fan, users will feel very comfortable in the cooling area; the air circulation formed by the chilled beam is very uniform, giving people the feeling of being in nature, which will increase the users' sense of warmth and nature, thus improving the quality of life. Among them, in summer, the area on the left side near the window is affected by solar radiation heat and conduction heat, making the natural convection in this area obvious. The air forms a large buoyancy, and it is easy for the supply air flow to be blown away from the glass outer window.

This phenomenon is called the blocking effect, resulting in the poor distribution of local high-temperature air in the peripheral area. Therefore, the jet direction of the air should avoid being perpendicular to the glass.
Case Appreciation: