The days when "thermal mass" was an important phrase in reference to radiant heating systems are long gone. Although the concept is still one that is paramount to understanding the way that the technology functions, the idea of conductivity has emerged in the industry as a notion of the utmost importance.
Early radiant heating systems were reliant on concrete slabs that stored heat generated from the sun during daylight hours. These passive systems would provide warmth once the sun went down, essentially delaying the release of the heat for about 12 hours.
This delay was initially a benefit of these systems, as the schedule would work for homes that needed to provide heat after the pinnacle of the retention of the sun's rays.
This delay in passively heated homes is something that technological advances have outed as an issue with concrete slab systems. A complaint arose that the thermal mass that was responsible for the delivery of heat took too long to deliver the necessary warmth to a residence.
In any home, the heat load changes can occur much too quickly for high mass systems to respond, as homeowners often complained of their residence being too cold in the morning, but too hot later in the day. This problem was exacerbated for families who wished to heat their home after being absent for a period longer than 12 hours.
This made companies consider using highly conductive materials to help expedite the process.
A highly conductive radiant floor system causes heat to flow into the conditioned space at the same quick rate that it flowed out of the designated area.
For more information regarding the importance of conductivity within a radiant heating system, click here.