The Basics Of Radiant Floor Heat
Radiant floor heat is becoming popular in most new homes. What is it and why is it a desired feature in new homes? Can it be added to an existing older home?
Imagine waking up in the cold early morning and walking into your kitchen to make a cup of coffee. If your kitchen is tile, like mine, it could be a very cold trek. But with radiant floor heating the experience is much more enjoyable. Instead of stepping into a cool room with a cold floor the floor is warm and pleasant. The floor tiles are heated from beneath by water or electricity, but occasionally by forced air. For residential applications the most efficient radiant floor heat is either electric or “liquid” also known as hydronic. Thermostats may be installed to control the heat in each area according to usage and may be programmed to a specific temperature for a specific day part.
Hydronic systems consist of a series of pipes installed beneath the floor which carry heated water throughout the area and return to the heater. The best systems consist of a boiler with pumps, valves and thermostats. Hydronic radiant floor heat is either done ‘wet’ or ‘dry’ installations. Wet installations consist of tubing embedded in concrete. The entire concrete sub-floor acts as a conductor, spreading heat throughout the floor which then radiates up into the room or rooms. Dry installations consist of tubing running in the air space beneath the floor or between two layers of sub-flooring material. Hydronic systems are a popular choice for solar powered heating. (Electricity is still required to pump the liquid through the system.) It is possible to use hydronic radiant floor heating in a smaller space with a residential hot water heater instead of a full home size boiler. Disadvantages unique to the hydronic system are initial cost, especially in a new solar heat application, thickness of slab required for wet installation and possible maintenance issues with the pumps and valves.
In floor radiant heat, the system is usually installed under tile or laminate flooring on a thin layer of concrete. It can be built into the floor with cables or installed with a mat purchased at your local home improvement store. More than one mat can be installed on one thermostat. You can also have the electric floor heaters installed with a “dimmer” light switch instead of the expensive thermostat. This saves money at the outset, but costs in the long run as the switch can be flipped accidentally and the floor temperature takes hours to change, using up costly electricity before you realize the error. The mats come in different sizes and are thin enough that they can be used in a remodel situation without causing significant floor height differences. Before you begin the project it is best to decide the layout and plan the thermostat location accordingly.
Disadvantages to any radiant floor heat system include the initial financial outlay for installation and the ‘lag time’ for the floors to get hot – but this is easily overcome with correct thermostat programming. Advantages are the comfort of a warm floor, the quiet operation as compared to a traditional furnace unit and the reduced turnover of room air that requires more air to be heated. Also there is a considerable probability that your on-going home heating costs will be reduced.
