High air flows are achieved through flexible duct. Compact overall dimensions. 3 speed fan settings, selectable at installation

That's how it stands currently, the red pairs of lines are the current ducting - he decided to duct to the side of the house, I am proposing switching to the front, but joists might make it as sensible to go to the same side.High quality ball bearing, long life motors, continuously rate and warranted for a minimum of 30,000 hours or 3 years.

And re-visiting my mention of the bigger more beefy fans, would it be wise/sensible to go for 150mm ducting and then use a reducer if I can resurrect the current 100T. Total distance should be radically reduced anyway, and there should be no turns apart from necessary ones, into the fan and out of the house, although I am thinking to mitigate at least the one out of the house by just using a 45 degree elbow, and then cutting the pipe going out at an angle to give a flat exit if that makes sense. The Manrose 4 inch inline fan provides a high extraction rate whilst keeping noise to a minimum. The mixed flow created by the twin blades enables the fan to pull more air than a conventional extractor fan making it ideal for use in bathrooms and other areas of high humidity. Fitted with a high quality ball bearing motor, MF100S is continuously rated and guaranteed for a minimum of 30,000 hours or 3 years.The isolator switch works, which is a bonus, the electrics at the top had no water ingress or moisture inside. Over the years I’ve always used 4” fans personally and never had a problem with excessive condensation or steam (except when something needs cleaning or clearing) despite the lengthy showers the family seem to like. Controlled by remote ON/OFF light switch. The extraction rate of 245m³/hr leads the way in performance and power. The Manrose MF100Sis a powerful inline extractor fan which is ductable up to 12m. An inline fan is installed in the loft or ceiling void above the bathroom (or kitchen etc). Ducting is attached to each end of the fan with one length going to an internal grille in the ceiling of the bathroom and the other going to a grille on the external wall, soffit or roof. Genuine Manrose branded product. High quality ball bearing, long life motor, continuously rated and warranted for a minimum of 30,000 hours or 3 years