Natural Climate Control using Radiant Heat from a Surface Heating System

Radiant heat instead of circulating warm air

Conventional heating and air conditioning systems use air to transport heat. The air should flow through the room as evenly as possible and distribute the heat in the process. Practice shows that this approach only works theoretically. Air conditioning systems create unpleasant drafts. Dust and germs rise from radiators with the warm air. Both are not only uncomfortable, but create a health risk.

The modern way to control the room temperature is to use radiant heating and cooling. Underfloor heating is generally regarded as a proven and reliable technology. Today it is no longer just a luxury, but often a standard in new buildings.

All room enclosing surfaces are suitable for thermal activation. This applies to both heating and cooling of rooms. With regard to the effects achieved and the efficiency, the results differ depending on whether the ceiling, wall or floor is used for activation. If you follow the motto “learn from nature”, the decision as to which area should be used for thermal activation is very easy. In most applications, ceiling heating and cooling is the best choice, because warmth to make you feel good comes from above.

Since water transfers heat much more efficiently than air, the energy required for heating and cooling distribution can be significantly reduced. Per unit of volume, water has a heat transfer capacity approximately 3,500 times greater than that of air. Water-based systems can therefore operate with significantly lower flow rates. The power required to drive the pumps needed for water circulation is low compared to the fan power of a traditional air conditioning system. Furthermore, in both heating and cooling modes, the water’s temperature is close to the desired room temperature and does not need to be heated or cooled at great energy expense.

A healthy indoor climate requires not only the correct temperature but also sufficiently fresh and clean indoor air. However, even if supply ventilation—necessary to ensure clean indoor air—is included in the operating cost calculation for the entire system, the use of water-based radiant heating systems still enables cost reductions of about 50% compared to a conventional air conditioning system. The comparative study “Climate Protection through Reducing Energy Demand for Building Cooling,” commissioned by the Federal Environment Agency, determined that over a 20-year period, the total annual costs for an office building with a cooling ceiling and basic ventilation were approximately 6 to 12 €/m², compared to 12 to 26 €/m² for a comparable system with full air conditioning.