User Manual

If the duct hygrostat is used for control, it is to be mounted in the extract air duct after
the room to be controlled.
If the duct hygrostat is used for monitoring the maximum or minimum humidity level, it is
to be mounted in the supply air duct.
The immersion sensor stem must be mounted either horizontally or vertically with the
stem pointing downward. It may never be mounted with the stem pointing upward.
To ensure accurate humidity measurements, it must be made certain that the air to be
measured is sufficiently mixed at the point of measurement.
<
5
m
/
s
>
5
m
/
s
1514Z02
The mounting orientation is dependent on the air velocity in the ductwork: at <5 m/s, the
holes in the stem must face the air flow; at >5 m/s, they must be perpendicular to the
direction of air flow (see illustration above).
When mounting the hygrostat in air ducts, the minimum immersion length of the stem
(130 mm) must be observed. The mounting flange supplied with the unit allows the im-
mersion length to be adjusted between 130 and 156 mm.
The hygrostat should be mounted on an inner wall approximately 1.5 m above the floor
and at least 0.5 m from the next wall.
At the location where the unit is mounted, there should be a natural circulation of room
air (no draughts, no corners of the room, not behind curtains, not too close to doors and
windows, and not on an outer wall). Sources of heat and refrigeration (radiators, com-
puters, TV sets, concealed heating pipes, hot or cold water pipes) must be in an ade-
quate distance.
The hygrostat should not be exposed to direct solar radiation.
For wall mounting, the mounting flange supplied with the hygrostat must be used.
The unit is supplied with mounting instructions.
The devices are considered electronics devices for disposal in term of European Direc-
tive 2012/19/EU and may not be disposed of as domestic waste.
• Dispose of the device via the channels provided for this purpose.
• Comply with all local and currently applicable laws and regulations.
Mounting notes
Air duct mounting
Mounting positions
1514Z01
Minimum immersion
length
Wall mounting
Mounting instructions
Disposal
3/5
Siemens Duct Hygrostats QFM81… CM1N1514E
Building Technologies 2014-07-30