This is the problem motivating our study of a building cooling technology called hydronic radiant systems which use less recirculated air, and in the process, could save energy. Our efforts have taken the form of projects to characterize the technology and to develop a computer model. The model is based on the finite differences method and covers both active and passive building elements. Reduced Air Transport Traditionally, HVAC systems are designed as all-air systems. These systems reduce the amount of air transported through buildings significantly, because the ventilation is provided by outside air systems without affecting the recirculating air fraction.
Radiation provides most of the cooling, using water as the transport medium.
The separation of cooling and ventilation tasks not only improves comfort conditions, it also improves indoor air quality as well as the control and zoning of the system. Hydronic cooling systems combine mechanisms to control the temperature of room surfaces with central air handling systems. A core-cooled ceiling is the cooling equivalent of a floor heating system. In this system, water is circulated through plastic tubes embedded in the core of a concrete ceiling. This layout allows the system to take advantage of the storage capacity of the concrete, and provides the opportunity to shift the building peak load away from the utility grid peak.