Obviously, the more insulation that you put in, the less heat loss you will have. When installing tubing in a concrete slab, it is important to have insulation under the concrete slab to limit the downward heat loss. The tubing is attached to a mesh with a standard slab poured over the top of it. The ends of the loops emerge from the concrete at the manifold locations. For most new construction and some remodeling projects, lightweight concrete provides an excellent mass for heat storage and transfer.
Tubing is secured to the sub-floor and a lightweight concrete mix applied over the top.
This becomes the new sub-floor. An aluminum plate system can be installed on top of a sub-floor, or from underneath the floor joists, in a remodeling project. The Radiant System requires hot water. How you heat it depends upon what is the most economical and efficient in your area. Usually the next higher size available unless the design is also for future system expansion.