Smart Windows

The main issue of existing low emissivity windows is that the E coating is either placed on the outer (max. solar gain, desirable in winter) or the inner side (min. solar gain, desirable in summer) of the glazed unit.

But if a smart reversible window is installed, then users can rotate the sash from a winter to summer position and vice versa to change the position of low E coating to select the right configuration.

Bergamo® Tecnoligie Spzoo was established in 1996 and has developed the design and development of the smart windows.



The development of windows, window frames, glazing and window closing mechanisms utilize a unique closing mechanism, which allows the window sash to be turned around by 180 or 360 degrees and locked in the opposite position.

Each window is fitted with an inside and external pane of glass which permit various amounts of solar radiation into the building at different times of the year.

Each window can be regulated and controlled manually or electronically.



Potential energy use reduction using a reversible window with different glass configurations has been estimated by performing a sensitivity analysis.

The graph visualizes the benefits of the reversibility, given a specific glass configuration. Selection of glass configuration is highly dependent on the cooling demand.

graph window

Simulation results shows the reduction of energy demand due to the smart window configuration ‐ the maximum reduction 5.8 [kWh/m2 floor area] corresponds to 39 [kWh/m2 glass area]. The reduction is calculated as the difference in energy demand with a reversible window and a fixed window in solar protection position.



A speculation is that the potential for the smart window may decrease, if implemented in an already highly retrofitted building where heating season is short and energy demand is already low.

rotating window  closed window

The innovative window concept is based on the idea of reversing sash in vertical or horizontal position through the central axis.

  • Prototype dimensions 900x1400mm
  • Wooden profiles thickness of 90mm.

The reversible window can contribute to lower energy consumption as well as comfortable indoor climate and conditions the whole year round.