YES! Get the appropriate capacity size fan. Find the cubic volumn (length x breadth x height). Then multiply the result by the number of air changes per hour (eight to ten). That gives you the capacity. So a bathroom that measures 8' x 8' x 8' (512 cu ft) and needing eight changes ph would need a fan with a capacity of 4096 cu ft. Err on the side of greatness if necessary.Buying a house (terraced with the bathroom in the middle between 2 bedrooms) ie. no windows as not on an outside wall. Does there need to be ventilation.