March 5th, 2008

Radiant Heating: Is It For You?

Posted by Shayna Prunier

A new trend that is “radiating” around green homes right now is using a radiant heating system rather than conventional forced air systems.  Speaking from experience, since I am currently installing radiant heating in my own home, I hope to arm you with some additional insight into this type of system.  

The Benefits of Radiant Heat Systems

The intent of a radiant heating system is for heat to radiate upward from the floor surface which acts like an ultra-efficient low level radiator.  Rather than forcing air to come out of a single vent in the ceiling, wall or floor, the radiant system creates an even flow of warm air that starts from the floor and naturally rises to heat an entire house.  The heat usually comes from tubes filled with warm water that are embedded into a concrete or plywood sub-floor.  There are also electric coil systems that can be used in smaller areas or exterior surfaces.  Keeping such a large surface like the floor at an even level of heat will warm other objects and people in a room rather than directly heating the air.  In a well insulated home, the heating temperature can be kept lower with a radiant heat system, and this results in lower energy use and costs.

Radiant heating can also improve your indoor air quality. If you don’t properly maintain a conventional forced air sytem (which entails cleaning the air ducts every year and changing all the air filters) you could be blowing allergens and even toxins around your home. Radiant heating systems have no filters to change and will never run the risk of polluting the air. One more added bonus is the silence of a radiant system, no fans blowing, sideboards creaking, or water gurgling.    

There is no question that radiant heating is warm and cozy, but does it make sense for all green homes?

The upfront costs of installing a radiant system are more expensive than a conventional heating system and may not produce as high a return on the initial investment.  If you live in an older home in a colder climate, and in an older energy-inefficient home, radiant heat can be a very worthwhile investment. It would particularly make sense if you are planning any floor replacement work already.

However, if you have a fairly green home already (or are building one), it is likely already designed for energy efficiency (e.g., you probably have good insulation and an energy-efficient furnace).  These homes often utilize passive solar strategies combined with good insulation to control thermal comfort.  A radiant system might be overkill and potentially provide too much heat for some well designed green homes.  For example, if you live in a warmer climate, it may cost $10,000 to install a radiant system to offset $100 worth of heat per year.  This may make sense if you like being able to walk on the bare floors all year round, but it should be something to think about when it comes to prioritizing the green attributes for your home.   

Another thing to think about is the flooring that will rest on top of the radiant heat system. BE SURE to check with the warranty of your finished flooring manufacturer or installer to avoid any potential problems.  There are some wood manufacturers that will not warranty a floor if it is put over a radiant system. 

How Can I Get a Radiant Heating System?     

There are a variety of methods and manufacturers of radiant heating systems.  If you are building a new home, you can work with your contractor and plumber to install a radiant system right into a new foundation.  Companies like the Radiant Floor Company will map out and design a system that works with the heating zones within your home. 

If you are renovating and keeping the existing floors, there are products like Uponor’s Quik Trak, WarmBoard, or GCS Radiant that will go over virtually any material and create a great subfloor for your finished flooring material. 

For those of you in cold climates, it is not too late to install a radiant floor and still enjoy it for the rest of the season.  If you are in a warmer area, you may want to do a little more research.  As with any green decision for your home, it should be dependent on your own green goals.  Help us radiate the word on radiant systems and let us know of your experiences.