Systems rated at 160 w/m² and 200W/m² are installed on uninsulated concrete floors with good results both in conservatories and internal rooms. However, due to the thermal dynamics involved, a cold uninsulated concrete subfloor will absorb up to 30% of the heat load down into the floor.
Without insulation the heat up rate is slower and running costs are higher. It is a fact however, that many installations have critical floor levels and a layer of insulation is not practical.
To make the best use of the system, insulation should be installed, either below the subfloor or as a layer of insulation backing board on top of the subfloor, OR BOTH.
Insulated floors pay for themselves over time with energy saved.
– Updated: January 2020