Free-Cooling mode, in combination with Air Changes Ratio→nmin=5(h-1) is essential for VMF concept and its efficiency.

The unit will maintain Troom during intermediate seasons (spring, autumn with Tambient≥10oC and ≤20oC), which form 30-40% from the total annual working hours), only by using free-cooling and ventilation, without compressor's work.

Night cooling mode works on the same principal. In these modes Damvent maintain Troom of the whole building, with very low energy consumption of the supply/extract fans. These are high energy saving features/modes, that cannot be obtained by the existing systems