Floor heating system and floor-heating device and hollow connecting member

Claim 2

A floor heating system comprising: a plurality of double pipe structures each including outer pipes and inner pipes disposed parallel to each other under a floor so that heat emitted through said outer pipes can heat the floor, said double pipe structures extending between and being connected at opposite structure ends to a pair of parallel main pipes; one of water and a thermal medium fluid is sealed in said double pipe structures between said outer pipes and said inner pipes; and a heat generating body; said heat generating body being inserted within each said inner pipe through openings at inner pipe ends which are projected from ends of said double pipe structures beyond said outer pipes.

Claim 3

A floor heating system in accordance with claim 1 wherein: said heat generating body includes a continuous electric heating wire inserted within said inner pipes; projecting ends of said inner pipes of said double pipe structures passing through said main pipes; said electric heating wire is passed through a first-row double pipe structure from an inner pipe first end to a second inner pipe end; said electric heating wire is passed through an adjacent second-row double pipe structure from a second end of its inner pipe to the said inner pipe first end; said electric heating wire is passed through an adjacent third-row double pipe structure from a first end of its inner pipe to the second end of said third row double pipe; and this process is repeated until said electric heating wire is passed through a double pipe structure disposed as a last row of such.