Dimensions and duct outlets Figure 1. Dimensions and duct outlets Inner diameter of the female collar ∅ 160 mm (R and L models). Duct outlets, R model and L model 1 Supply air from the unit to the apartment 2 Extract air from the apartment to the unit 3 Exhaust air flowing outdoors from the unit 4 Outdoor air to the unit Figure 2. Condensing water outlet dimensioning