From surface heating to full surface heatingTo increase the coefficient of performance of the heat pump, every degree less flow temperature counts. We take this to the extreme with full-surface heating!
To simplify full-surface heating, water was replaced by air in February 2025. While the system was previously limited to walls for cost reasons, it is now also being fitted to floors and ceilings.
The possibilities with better thermal insulation and heat recovery from exhaust air have been used up. What remains as an optimization is to increase the coefficient of performance of the heat pump. The lower the temperature difference, the better. Low-temperature heat storage and producing heat from the air only during the warmest hours of the day, skipping cold spells, is one part of the strategy. The other part of the strategy is lowering supply temperature by adding more heating surfaces. From radiators to optimized radiators, on to floor heating. Still further to the combination of wall heating and underfloor heating. But even that can be increased with full-surface heating.
Here are examples of how different flow temperatures affect the coefficient of performance of the heat pump. A 2° warm heat source and 40% of the theoretically maximum achievable coefficient of performance according to Carnot are assumed.
In a conventional setup, 10 m of heating pipe per m² of wall is common. With 16 mm aluminum composite pipe with 12 mm inner diameter, this is 1.13 liters of water per m² wall. Our last wall construction before the invention of full-surface heating in August 2022 therefore also only had a heat storage capacity of 14.9 kJ/m²/K, which is relevant for the interior. With the new wall construction with full-surface heating, this increased to almost 14 liters of water per m² of wall and 75 kJ/m²/K. |
GEMINI next Generation AG – Technology
