Greenwood CMEV.4E Low Energy Constant Running Central Ventilation Unit

Fitted in a loft above two bathrooms the unit is inaudible in the rooms below even at max speed. Speed of airflow is infinitely variable. Set the trickle low rate and set the maximum boost rate and the system automatically assigns the fan speed of the mid setting midway. The only noise is from the significant airflow on boost setting through 4-inch ceiling vents. Could be made near inaudible even on boost by fitting 5-inch ceiling fittings. The device is designed for 5-inch/125mm fittings, but works OK with 5-inch to 4-inch/100mm adaptors. Would definitely buy again.

Brilliant bit of kit. Highly recommended for flats.