If you are looking for a quiet replacement fan in the bathroom going through the wall, then the Brookvent Aiirstream Xe 100T or the Silent 100 CRZ with its seven year guarantee is a good choice. If you are going through the ceiling with a short duct run, then the S&P Decor CR, Silent 100 CRZ and Nuaire Faith are good choices. If you have an attic space, the inline S&P TD 160/100T is a powerful and very quiet intermittent fan. If you are suffering from mould problems, we strongly recommend dMEV fans which are very quiet constant running fans. The S&P Silent Dual 100 is a good dMEV fan for going straight through the wall in a bathroom. If the fan is in the ceiling and depending on the length of ducting, we recommend the Nuaire Faith dMEV, S&P Eco dMEV HLC, Envirovent Filterless fan range, with the EnviroVent Filterless fan been the strongest fan. The EcoAIR dMEV range of fans and the Silent Dual 100 can be used as constant running fans or intermitting fans by changing the settings. If you need help choosing the correct fan for the right location, please contact us for technical advice.