Energy Flow Wall is a new revolutionary concept where the main source of energy is the sun, helping to achieve the best indoor climate and the lowest energy cost by ventilating, heating, and cooling a building.

The components of the system are Sun Walls with containers filled with PCM (Phase Change Material), Ventilation Windows, electronic control of indoor climate and energy, a control system, and an extraction heat pump placed in the building to reuse the energy from the waste air.


The Ventilation Window was invented in 2004, with the intention of supplying a building with fresh preheated air instead of the installation of a ventilation system. The Ventilation Window can supply the building with fresh air from the outside both night and day, but the sun can only preheat the ventilation air passing the window as long as it shines. The rest of the time, the ventilation air is only preheated by the heat loss from the building.

Further developments in Energy Flow Wall have now added a Sun Wall to the system. In the Sun Wall are containers with PCM installed. The PCM is able to collect and store energy from the sun during the daytime to be released during the night when we don’t get any direct heat from the sun, and in that way supply the building with energy when it is most needed.

To ensure that all rooms are ventilated and heated/cooled, the system has sensors to measure temperature and occupancy in each room.

To avoid exhaust air from the building allowing heat loss, an exhaust heat pump is placed in the building. It ventilates the building and reuses the energy from the polluted air before it is sent out from the building.

All the behavior of heating sources and the extraction heat pump is under electronic control and constantly regulated by a control system designed for the house.

To regulate the temperature and indoor climate in each room, the owner of the building has a mobile app and/or a control panel in the house.

Service may be done by the service team at Energy Flow Wall ApS, either online on through or a direct visit