RADIANT PANELS > THE EVOLUTION OF HEATING THROUGH RADIANT FLOORS
HISTORY: THE OLD SYSTEMS
Ancient thermal bath
Thermal floors can be traced back to up to 2000 years ago, when the architects invented the so-called ‘hypocaust floors’, from the Greek “heating from below”: smoke and hot air coming from a hearth close to the building would flow through determined pipes built underneath the floor. In the ancient Rome, aside from heating the air in specific heat rooms, the geothermal system was also used in order to provide heating to large environments as well as the thermal baths.
METALLIC RADIANT FLOORS
Corroded metallic pipe
Far before the discovery of the modern radiant floors, in the 60s the first radiant floors were made with metallic pipes which would be placed in the middle of the joists in between blocks without any insulation. Metallic pipes were placed at 50 cm of distance one another and the same circuit would heat different environments; for this reason there was no way to set the temperature room by room. With aging, the metallic pipes – both in steel or copper – would be damaged due to corrosion or electrolysis.
Furthermore, since they had a small contact with the surface, the main features of these systems was the incredibly high water temperature, which would reach even 60°C in order to achieve 20°C in the room. The floors therefore had alternated spots: some unbearably hot and others that were way cooler.
For this reason these systems would:
- Give feet swelling problems
- It wasn’t possible to set the temperature room by room
- The metallic pipes would get clogged and corroded
- It wasn’t possible to achieve a summer air-conditioning
RADIANT FLOORS WITH PLASTIC PIPES AND OTHER SYSTEMS
Plastic represented a solution to several problems: the systems are faster to install, and it is easier to flex the pipes; however a radiant floor system can give problems if it is not designed well and if it is not installed by specialized technicians.
One of the main advantages of using plastic pipes is that it is possible to avoid joints underneath the floor as well as decrease the distance between pipes. However there are several plastic pipes that can be used, and each one of them has different chemical-physical features. Normally the best choice implies a higher cost, but unfortunately sometimes pipes that aren’t guaranteed to last long are used and joints underneath the floors are made.
For radiant floors also polybutylene and polypropylene are used, but these materials can age suddenly; this molecular aging occurs already after a decade. This doesn’t happen with reticulate polyethylene with thermal memory, a material that is chosen and used by Deltasolar for its systems.
The quality of the pipe used, however, is not enough if a heating system is not designed well and installed by specialized technicians.
Analyzing in the 70s some German systems still used by some companies , we realized that there were several discrepancies determined by an approximation in the computations and the installation. Still nowadays, to simplify things, some companies use simple computations based on two or three types of fixed inter-axis such as 10, 20 or 30 cm. For this reason the amount of pipe can vary creating extreme thermal discrepancies in the environments. To fix the pipes some companies use polystyrene mushrooms that limit the heat dispersion and cause an increase in the water temperature; this results in feet swellings and an energy waste.
PROBLEMS WITH THE OLDER SYSTEMS
Thermography
As it can be noticed by the thermograph, this type of ‘coil’ installation in very inconsistent as far as distributing the heat. On one side of the floor there is a temperature that is higher of a few degrees in respect to the other side. Furthermore, with this system it is not possible to obtain an air-conditioning during the summer, because it would result in extreme condensation on the floor.
Coil pipe
A feature of these older systems is the installation of the ‘coil’ pipe: notice the large empty spaces that cause the inconsistence of the heated surfaces. Furthermore, with this ‘coil’ system, the water flow creates electro-magnetic fields, which have a bad influence on people’s health. With the ‘opposite spiral’ system, the water flows in alternated directions, and therefore the electro-magnetic fields cancel
each other out.
Rusticated insulating panels
Rusticated insulating panels. With this type of panels the pipes are too tied up, and it is not possible to place them according to the thermal needs, nor avoid background protrusions. For this reason, with these systems it is necessary to create an expensive background that has to cover all the other systems. The thickness needed is of about 118 to 120 cm. The protrusions of the insulating panels also represent a thermal barrier, which interferes with the heat distribution. With Deltasolar’s system, only 5-6 cm are needed in the most critical cases, while for normal cases only 10 cm will suffice.