Studies have shown for years that having a thermal mass to retain and release heat is the most effective and efficient way to heat an area. To achieve this in your home, tubing is attached to the wooden floors and then a gypsum based concrete of 1 ½" is poured over the tubing. Once this cures, the finished floor can be installed directly over top. The theory is that when the radiant infloor heating system is on, tubes carrying hot water begins to heat the concrete rather than just releasing heat into the air. The concrete (thermal mass) then starts to radiate its' heat very evenly and for a long period of time. If the room has the right exposure the sun can help heat the mass, even in the winter. Floors often are still warm 12 hours after the system has been turned off. This system is especially effective in the basement. Radiant tubing is attached to the rebar and then the concrete floor is poured making the entire basement a thermal mass. In the summer the night air cools the floor. This energy is then released during the day to assist the home's A/C operation.
To gain a thermal advantage, stone or ceramic tile flooring can be used on top of poured base layer. Tile holds temperatures much better than wood. In certain installations you may want to consider insulating the underside of the ceiling below the primary space if the lower level, like a basement or crawl space, is not used as frequently. We can assist you with determining the necessary areas to insulate in your particular case.
The thermal gain is significant since masonry materials hold the heat and the cool for up to twelve hours and re-releases it back into the room. As a result, the demand on your A/C or furnace is reduced during that part of the day. This works great in conjunction with radiant floors and/or rooms that have southern exposure and overhangs that shade in the summer and let heat in over the winter to warm the thermal mass. Similar benefits can come with thermal mass walls or even water tanks positioned strategically in the home.
The return on investment of having a thermal mass is 13.3%, this does not take into effect the added comfort level.
The ROI Calculation is based on 1,000 square feet of floors with utility bill savings in both summer and winter.