Principle

Principle of air conditioning/heating by radiation.

In heating, there are two main modes of transfer of the heat: the convection which warms the air (convectors), and the radiation, that of the sun for example, which  directly transmits its heat to walls, objects and to our body.

All bodies emit infrared radiation, which are heating. Two objects of different temperatures radiate to each other, the warmest one exchanging its heat for the benefit of the colder one.
 
Radiation from the ceiling
 

In this case the determining temperature is not that of the air, but that of the walls. An experiment was done in a room where the air was refreshed down to 10°C (50°F) but the walls were warmed: the occupants felt warm. 

The cooling of the air is not enough to compensate the heat due to the radiation of walls and people feel uncomfortable. This experiment proves the determining role of the wall temperature for the comfort feeling. The same experiment was done is the winter and gave the same results concerning comfort

The man continuously exchanges his heat with his environment. A fast loss of heat causes a sensation of cold. The body succeeds in maintaining its thermal balance by bringing in unpleasant additional regulating mechanisms such as the shudder.

It is necessary to obtain a point of thermal neutrality coinciding with an imperceptible loss of the calories of the body. This corresponds to the temperature of comfort, determined by the air temperature, the wall temperature, the air speed and the hygrometry.

That is why heating/refreshing by radiation perfectly suits the need for comfort.
 
 

"We give to buildings a thermic life."

A network of capillary tubes allows water circulation to convey the heat or the cold through the building. These tubes, arranged in the ceiling, the walls, or even the ground, transform the simple walls into active elements, and, by opposition to fan coils or AHU, ensures an unequalled quality of indoor environment.
 
 

That was our preliminary conception as we were developing the cooling ceiling with capillary tubes back in the 80's. Similar to the blood vessels in our body, the KaRo capillary mats get the heat produced in the building evacuated towards the outside, under the control of a local or centralized regulation, which, as in the human body, regulate the streams of heat. The air conditioning by radiation is the only one to require no recycling of the air. This allows to:

  • Protect the quality of the air without draft,

  • Create no acoustic nuisance,

  • Reduce the energy consumptions (to bring the same quantity of heat, the volumes to be conveyed are 1000 times more important with air than with water).
 

The KaRo mat

The heart and center of the KaRo system is the mat of capillary tubes. This mat consists of a a grid of flexible and very thin tubes (3 mm / 0.12 in diameter) with collectors of variable diameter: 10, 15, 20 mm (0.4, 0.6, 0.8 in). The small thickness of KaRo mats allows their mounting straight on the surface of walls, ceilings and floors. One KaRo mat transforms passive elements of construction into heating and cooling surfaces.
 

Particularity

Capillary tubes always present a laminar flow: The positive effect is that the head loss grows only linear with the amount of extra water, and not quadratic. 
 

Materials

KaRo mats are made out of polypropylene (P series), or copper (C series).
 

Types of KaRo ceilings

The various types of KaRo ceilings available are: 

Plaster coated KaRo ceiling 
Metal KaRo ceiling
Plaster board or StoSilent® KaRo ceiling
 

More light

That is why the architect of Stadtsparkasse (City Savings Bank) in Cologne chose an oblique ceiling. Normally the energy cost to warm or cool should be higher, because of the extra space in the room, but KaRo mats compensate this very effectively.
 

 

The concept of KaRo safety 

The concept of  KaRo safety guarantees the exploitation of KaRo ceilings for many years. It includes system, production and assembly.