- In terms of efficiency – how much of the available heat stays in the building vs. how much is wasted-there is no difference between a concrete suspended slab system and a staple up system within the floor joists. There is, however, a performance difference, a difference in how much heat each system is capable of putting out. Slabs, suspended or on grade, put out more heat (50 BTUs/ sq. ft.) than systems within floor joists (35 BTUs sq. ft.). However, well-insulated residential structures need only 20-25 BTUs sq. ft. to maintain comfortable temperatures at zero degrees F, so either arrangement will provide sufficient heat.
- In rooms with high ceilings or extensive glass where higher performance is desired, there is an alternative to the suspended slab. By strapping the floor with 1x4s or 2x4s, placing the tubing in the spaces in between and filling in the areas between strapping and tubing with sand, dry mix or cement, you will gain most of the advantages of a slab without the cost and weight. Flooring is then nailed to the strapping. This procedure is described on page 10 of our Installation Manual.
