One TwinFresh unit can serve rooms up to 343 sq. ft. To arrange a ventilation system based on TwinFresh Comfo ventilators, install one unit in each room. For larger premises, install two ventilators. Each ventilation unit is controlled independenly so you may adjust a ventilation mode for each room considering the individual preferences. Air flows from one room to another through door grilles, openings or halls and ensures required circulation in premises.