To better understand radiant heat, let’s first discuss thermal energy and heat transfer. “Thermal energy” is just a fancy way to say “heat.” Thermal energy always moves – from the warm object to the cooler object. This radiant heat transfer can occur in three ways.
First – there is convection. Thermal energy is transferred by air movement. In a forced-air heating system, air is blown across a hot surface – then it carries that heat through ductwork. When that warm air is blown into the room, the air temperature rises and the objects in the room are heated by the air. The downside is – air movement tends to cool the human body, which makes this method of heating counterintuitive to the idea of comfort.
Second – there is conduction. A heated surface comes into physical contact with a cooler surface. Thermal energy is transferred from warmth to cold by contact. This is an efficient way to transfer heat – but when it comes to human comfort – it’s not easy to keep your body in constant contact with a heat source. Just try it sometime…
Third – there is radiant heat. Energy is transmitted as an infrared wave from a heat source to a cooler object with very little heat loss in the process. Our planet receives energy from the sun in the form of radiant heat. the space between is very cold, but because the thermal energy travels as an infrared wave – very little energy is lost – and it heats the first solid object it comes into contact with, our planet.
This is the primary principle at work in a radiant heating system. Instead of blowing heated air around, you turn a surface into a heating panel and radiate thermal energy into the room.
The logical choice is to turn the floor into a heating panel. Heat will radiate from the floor to the objects in the room. In addition, cool air at the floor will be heated and gently rise and spread throughout the area. An in floor hydronic heat system can be custom designed to do just that.