Special fans that control both air intake and exhaust are needed for room ventilation in both new and renovated buildings. Until now, fans with forward-curved impellers were used for central home ventilation units with and without heat recovery. But the proven RadiCal centrifugal fans with free-running backward-curved impellers deliver significantly better results for both efficiency and noise emission. Now ebm-papst has combined its proven RadiCal with an aerodynamically optimized scroll housing for use in central home ventilation units. Several benefits in practice The scroll housing with its round exhaust opening connects directly to the pipe fitting on the ventilation unit’s outlet, considerably reducing the usual flow losses while the air performance remains very pressure-insensitive and the efficiency increases by up to 34% compared to centrifugal blowers of the same construction. In addition, the noise level is reduced by 3.5 dB(A), as already confirmed in numerous tests. Installation-induced noises that arise during operation and are undesirable in living areas can also be reduced. The optional FlowGrid air inlet grill can be mounted on the intake side if needed. This results in agreeable acoustic characteristics as it minimizes unpleasant low-frequency sounds caused by obstructive fittings inside the unit. The fan is controlled and its operating data read out via the MODBUS RTU option. Plug & play system, ready to install The RadiCal centrifugal fans in 3D scroll housings are offered as ready-to-install plug & play solutions in size 190 with various output levels up to 170 W. They will be available from April 2017.