The ASHRAE design recommendations for radiant heating panels are reviewed and evaluated using the results computed from a numerical model. The panel configuration that was considered consists of hot water pipes buried in either a bare or a covered concrete slab floor with a concrete footing and perimeter insulation. The numerical model is described in detail and uses a finite control volume based solution method. Particular parameters of interest are the downward and edgewise heat loss, the panel thermal resistance, and the required mean water temperature.

Results of the numerical model were compared with prior experimental results and agree qualitatively. The ASHRAE design recommendations are shown to be adequate and are slightly conservative for designing both bare and covered floor heating panels with no infiltration and with an area-weighted average unheated surface temperature, AUST, equal to the room air temperature. The ASHRAE design recommendations are conservative because both the downward and edgewise heat loss and the panel thermal resistance are overestimated.

Units: I-P