An inline fan with such facilities would be kind of pointless - unless you want it to sense the humidity of your loft rather than the bathroom. ;-)
What you need is a standalone sensor like this :
formatting link
also puts the humidity control within reach rather than on the ceiling or in the loft.
You can parallel a standalone PIR with the above as well if you want motion detection as well.
You could...
Advantages of inline: freedom to chose an inlet vent of your choice (TLC do a nice shower light combined vent for example), quieter operation with less vibration. Pair it with whatever controls you fancy.
CF fan: not much to recommended it except you could possibly get a "one box" solution with a built in humidistat (which would be at ceiling level)
IIRC The requirement for a bathroom fan is a flow of 15 litres per second. Most fans will be able to do that.
Yup - as long as it has a permanent live as well as a switched one from the PIR it should run on for a user selectable time. Note you will also need a three pole isolator switch in the feed to the fan. If this is not going to be in the same room as the fan then it should be one that can be locked off.
I just had a look through part F of the building regs, and the only mention of data for bathroom intermittent mechanical extraction is the
15 l/s figure - they don't seem to take into account the room volume.
If you apply your 54 m^3 to a room of say 3x2x2m, that does in fact give you 4.5 air changes per hour, which seems toward the upper end of what would be required in a bathroom - especially without heat recovery.
Anecdotally, I have used a 4" humidistat fan in a bathroom with a high pressure shower. I found that it would keep most of the visible steam under control during the shower, and would have the room visibly clear within 5 mins or finishing. It would then take 20 - 45 mins to dry the all the room surfaces after that (that was all tiled, with two outside non cavity walls).
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.