Zero (S111) New Office Building with latent heat storage, Stuttgart, Germany

Zero (S111) New Office Building with latent heat storage

The energy and climate concept for the new office building is aimed at sustainable construction and robust building operation with optimization of thermal and visual comfort with the lowest possible CO2 emissions over the entire life cycle.

The focus is on ensuring air quality, especially at low outside temperatures, and also on limiting warming in the summer to counteract overheating. The goals are to be achieved by using robust technology with low maintenance requirements.
The four upper floors will be constructed in timber. The space program, the occupancy, as well as the flexibility of these office spaces were optimized in order to be able to implement the goals of a robust climate and energy concept. Low technical installation density, promise lower operating and energy costs with high quality of stay.

Measurements are taken on a mockup to test summer operation with a radiator running in cooling mode, as well as to determine performances.

The supply air for the office areas is pre-conditioned by means of facade ventilation elements with downstream preheating and pre-cooling. With the help of exhaust chimneys and the ventilation elements in the facade, the office floors can be ventilated mainly naturally. Maximization of natural ventilation and heat recovery from the exhaust air ensure energy efficiency and comfort.

The first floor is designed as a classic wooden building and houses meeting rooms of various sizes, a canteen with a full kitchen, and a fitness area.

An ice storage tank with a volume of 400 m³ (14,126 ft³) serves as a heat and cold source for a heat pump. Such a latent heat storage uses the energy of the phase change from water to ice. With the help of the heat pump, heat is extracted from the ice storage in winter until almost the entire ice storage is frozen at the end of the heating period. The built-up ice will then be used for free building cooling in the summer. Another source of regeneration is the recovered heat from the exhaust air.

With the planned climate and energy concept, a nearly climate-neutral building operation is possible. Certification in accordance with DGNB is being targeted.


Storing energy with water and ice :>