From surface heating to full surface heating

To 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!

Reduce electricity demand for room heating and cooling

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.

20° room temperature, 21° supply temperature

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.

Supply temperature	60°	50°	40°	35°	30°	27°	24°	21°
Coefficient Of Performance	2.30	2.69	3.30	3.74	4.33	4.80	5.40	6.19
Electricity for 1200 kWh heat	522	446	364	321	277	250	222	194

Wall and floor are almost 2,000 liters of buffer storage

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.