Profile: Manrose Manufacturing Ltd. specializes in providing ventilation fans, mechanical extract ventilation (MEV), heat recovery (MVHR), hand driers, and electrical heating & cooling accessories. Our 9 and 12 inch window fan is suitable for a variety of domestic and commercial applications. The WF230 range has been designed for window or wall mounting. It features extractor fans at an extract rate of 668 m3/hr, 185 liters per second. There are three models in the range starting with the basic unit (WF230) which has fixed louvers, can be supplied with an optional pullcord switch, and provides a natural source of trickle flow ventilation when the fan is switched off.