(January 2010) An innovative floor heating has been developed by the Portuguese Granisintra Company: „Stonecell“, combines natural stone as a heat reservoir with electricity as the source of thermal energy.
The system is comprised of three components. Plastic modules (40 cm x 40 cm und 4 mm), which are affixed to the floor through which the second component, the heating coils, are pressed. Natural stone tiles are the third component topping off the construction. The tiles are held in place by a click-system integrated in the plastic modules, which, in turn, may be screwed down. An aluminum band acts as a conductor to ensure uniformity of heat throughout the tile.
The system offers one major advantage to floor heating with warm water: The tiles heat up almost immediately. Approximately 15 minutes after turning the system on, toasty-warm room temperatures are registered throughout – even more quickly if a higher density of coils is chosen.
Another advantage is that the modules are very easy to install. It is also possible to apply the elements to a wall – vertically. The system can be dismantled and installed elsewhere with ease. And, should a tile be damaged, it can be removed and replaced.
The system is presently undergoing its test phase to secure patenting. The tests are being conducted by the Portuguese National Laboratory (LNEC). First tests were successful. So far Granisintra has sold around 5000 m² „Stonecell” and is using it in its own office complex since over 5 years. Two of the components are readily available: the stone tiles and the heating coil. Only the plastic modules are a development of Granisintra.
„Stonecell’s” Achilles’ heel is that heating with electricity is not ecologically optimal. Much of the primary energy is lost in producing electricity. So the system will likely find its biggest market in warm climates where it is the better alternative to heating with the air conditioner.
Granisintra’s headquarters are in Pero Pinheiro in the mountains behind the City of Sintra about 30 km from Lisbon. The Company has been working with granite since 1989, later expanding to other types of stone.