Chapter 4: RADIANT HYDRONIC HEATING SYSTEMS
4.1 INTRODUCTION TO RADIANT HYDRONIC SYSTEMS
Radiant hydronic heating systems accomplish heat delivery by means of panels that transfer 50 percent or more of total panel energy radiantly, a characteristic by which the ASHRAE Handbooks define all radiant systems. The distinguishing feature of radiant hydronic heating systems is the use of a liquid or fluid to transfer heat from the originating source to the radiant panel at the location of heat delivery. The focus of this chapter is the development of information about hydronic heating panel design, performance, and control characteristics.
Radiant hydronic systems employ a broad range of radiant panel configurations located on or in the floor, wall, or ceiling. The performance characteristics are impacted by the planar selection. Occupant proximity to the heat source, the split between radiant and convective heat transfer, and potential for heat-obstructing or surface-covering materials all are important considerations in plane selection for radiant heat delivery. Each location can accommodate a broad selection of hydronic equipment and design options.
Common radiant hydronic panels encompass a variety of floor design options to accommodate the complex range of new and existing building architectural requirements. Even though radiant hydronic floor systems normally embed the heat transfer conduit directly into the floor as the panel, the heat transfer conduit may also be placed on the underside of the floor. Each radiant floor panel design should be analyzed carefully to determine its unique performance requirements, as planned, as it could be installed, and as it might later be used.