Radiant Heat

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.

If you would like to know more about the process of designing and/or installing radiant heat - feel free to leave a comment or question below.

A radiant heating system is comprised of three main components - a heat source, a control system and a distribution system.

The heat source can be a boiler, a hot water heater, a heat pump, sometimes even solar panels. Anything that can produce enough heat can be used as the heat source.

The control system is used to send heat to different parts of the structure. With radiant heat, you can you can control zones - setting different areas up with their own individual thermostat controls. Valves or pumps can be set up to turn different zones on or off - or keeping them set to the temperature desired for optimal comfort.

The distribution system in a hydronic system utilizes piping. These pipes - most commonly PEX - allow the control system to send warm water to the floor. Remember the heating panel mentioned up above? The PEX in the floor transfers heat into the floor and provides heat whenever the thermostat for that area is calling for heat.

As an example - if the thermostat in the main living area calls for heat, the valves for the piping in that area open up and a pump turns on to circulate water through those PEX circuits. The floor begins to warm up and radiant heat is transfered into the room. Once enough thermal energy has permeated the room - the thermostat is satisfied and the zone is shut off.

If the heat source needs to provide additional heat during the cycle, it comes on and provides more heat for the system. In operation, it's really quite simple and comfortable. The simplicity is achieved by following precise hydronic heat and radiant design guidelines.