Chapter 8 - Chilled Beams and Radiant Ceiling System

Chilled beam and radiant ceiling systems provide excellent thermal comfort, energy conservation, and efficient use of space due to high heat capacity of water used as heat transfer medium. The operation of the systems is simple and trouble-free with minimum maintenance requirements. In chilled beam and radiant ceiling systems, the high temperature cooling and low temperature heating maximize the opportunity for free cooling and optimize the efficiency of heating. With radiant ceiling system, approximately 70% of the total cooling is by radiant absorption and the remaining 30% by convection if the backs of the tiles are insulated. The operation of chilled beam is based on convection. Chilled beam and radiant ceiling systems are dedicated outdoor air systems to be applied primarily in spaces where the required specific outdoor air flow rate and internal humidity loads are moderate. In design, attention should be paid to control those systems to prevent surface condensation. In order to keep humidity levels within the design parameters, the primary air handling unit normally requires the facility to dehumidify the supply air. The primary airflow rate should also be high enough to deal with the latent gains generated inside the space.