A liquid-container/ventilation-tube kit for a ventilation system that includes (a) a ventilator, (b) a respiratory humidifier having a housing and a liquid container, the housing having a pair of first electrical contact elements, (c) a first inhalation tube extending from the respiratory humidifier to a Y-piece, (d) a second inhalation tube extending from the ventilator to the respiratory humidifier, and (e) an exhalation tube extending from the Y-piece to the ventilator, the kit including the liquid container having a pair of first connection elements for removable connection of the first and second inhalation tubes thereto, and a pair of second connection elements each attached to a respective one of the first and second inhalation tubes and by which each of the inhalation tubes is pneumatically connected to a respective one of the first connection elements along a first connecting direction, each second connection element having a second electrical contact element that is positioned and arranged such that electrical connection with a respective one of the first electrical contact elements is possible in both of two ways, one when the pneumatic connection of the respective ventilation tube to the liquid container is effected after the liquid container has been inserted into the housing and the other when the liquid container is inserted into the housing after the pneumatic connection of the ventilation tubes to the liquid container has been effected.
