Convection heat is what you feel from air heated by warm air furnaces, heat pumps, and baseboards. The warm air is distributed mechanically or through natural convection. Long wave radiant energy is the most efficient form of heat transfer. Radiant heat is healthy, comfortable heat. Airborne dust, pollen, and germs are reduced by the elimination of blowing air.
Operating costs are lower.
Ceiling placement eliminates obstructions to radiant heat transfer. Actually heat doesn't rise, it's hot air that rises, creating natural convection like that from baseboard heaters and other warmer surfaces. So, the ceiling is best. Yes, radiant energy creates heat when it strikes the floor and furnishings, and the warmed surfaces reradiate heat, thereby warming the air. In this Florida office, radiant panels provide perimeter heat for a variable air volume system.