Plus-Energy Daycare Center, Bretzfeld, Germany

The proposed climate and energy concept for the two-story new construction focuses on high energy efficiency and low use of technology, thus ensuring low maintenance costs. Regenerative and local resources are used.
In addition to operable windows for ventilation, the concept for the required air exchange provides energy-efficient basic ventilation: This continuous ventilation works like a cascade, the supply air is introduced into the group rooms and then flows into the lounge and then into the bedroom. There the air is extracted, whereby a special heat exchanger, an enthalpy wheel, recovers heat and humidity at the same time for the supply air.
Conventional heat exchangers recover the sensible heat up to 90%, but not the (considerable amount of) energy of the latent heat needed to supply the room air with the necessary moisture.
An enthalpy wheel - or rotary heat exchanger with sorption technology - additionally treats the air humidity and uses the energy of the latent heat bound in it providing humidity in the supply air in an energy-efficient and cost-effective way.
Underfloor heating heats rooms in winter and can cool them in summer. Night ventilation via the very efficient ventilation system is also possible.
Daylight is extremely important because we humans need it for concentration, well-being and performance. Therefore, the group rooms on the upper floor are supplied with daylight both from the façade and via the specially developed air and light chimneys. On the exposed facades, the external sun shading system with daylight control prevents too much of a good thing.
A reversible heat pump supplies heat or cold. Energy efficiency in combination with local regenerative power generation through photovoltaics on the roof offers the possibility of a PlusEnergy building. Therefore, the entire roof area of the daycare facility is used to generate electricity and gains more energy in the annual balance than is consumed.
The planned daycare as a PlusEnergy building will accommodate growing generations with comfort and serve as an example of sustainability not only for children.
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