apparantly this 158 unit building has as many as 10 people living in one unit, they are having major troubles with moisture and mold, hence the consultant wanting to have a sensor close by to sense moisture and turn the fan on when nobody is home...he also wants to hide it so no one can fiddle with the adjustments.....and as i told him, putting it on the wall will still sense moisture and turn the fan on...
since new fans are going to be installed anyway, why not go with the Broan/Nutone units that Kjay sent a link to? This is the same principle as ceiling mounted humidistat. The built in humidity control should prevent tampering with the automatic moisture control, unless someone was really determined.
