Radiant Heating

To better understand radiant heating, let's first talk about thermal energy and heat transfer. Thermal energy is a fancy way to say "heat." Thermal energy always moves from warm to cold. This heat transfer can happen in three ways: convection, conduction and radiant.

Convection happens when you blow heated air across the object to be heated - like pushing hot air through forced-air ductwork. Conduction happens by solid contact - a warm object touches a cool object and warms it up. Radiant energy is transmitted as an infrared wave between two objects.

Radiant energy is how the sun heats our planet. The cold vacuum of space can't absorb and hold much heat - but once the radiant energy from the sun hits the mass of our planet - things start to warm up.

In-floor radiant heating is a way to use the properties of radiant energy to heat a structure as opposed to the more traditional convective approach associated with forced-air heating. To do this, we turn the floor surface into a radiant heating panel.

There are a few ways to make your floor a radiant panel. Small areas can be done with electric cables or mats. Most larger projects use a water-based (hydronic) system where warm water is pumped through tubing. Three major components are involved: a heat source, the distribution/control system, and the piping itself.

The heat source can be a hot-water heater, a boiler, a heat pump and sometimes even solar panels. Your radiant heat source will need to be sized according to the anticipated heat load of your project. A competent radiant designer will know how to do this for you.

The distribution/control system can be a simple copper manifold or a copper piping with pumps and tees. It may also be a valved brass or plastic manifold with zone and flow control valves - a pump or pumps - and a control box to tie your thermostats into the system.

The piping can be copper, but in most cases today - it will be a cross-linked polyethylene (PEX). Several grades of PEX are available (A, B &C) - you'll find most people in the industry recommend A or B for radiant heating. The main differences are the temperatures and pressures the PEX can handle and the flexibility of the tubing. The more flexible the tubing, the less likely it will kink during your radiant heating installation.

I hope you've found this information helpful. If you have, feel free to "digg" me. For additional information - please visit my website about: hydronic heat

Take care,

RadiantSteve