What is the definition of a Passive Chilled Beam? A Passive Chilled Beam (PCB) is an energy-efficient cooling system used in buildings. It is a type of air conditioning system that uses the natural convection of air to cool the space, making it more comfortable and energy-efficient. It is a two-piece system, which includes a cold beam and a heat sink. The cold beam is a long, wide, flat surface that is exposed to air in the building. As the air passes over the beam, it cools down as it absorbs heat from the surface. The heat sink is located underneath the beam to collect the heat from the air. This heat is then distributed to other parts of the building, creating an efficient cooling system. PCBs are commonly used in large office buildings, schools, hospitals and public areas due to their low maintenance and energy efficiency. Unlike traditional air conditioning systems, PCBs do not require additional equipment or energy to cool a space. They