diff --git a/custom_components/localthings/registry/capabilities/airconditioner.py b/custom_components/localthings/registry/capabilities/airconditioner.py
index 5958018..47c402c 100644
--- a/custom_components/localthings/registry/capabilities/airconditioner.py
+++ b/custom_components/localthings/registry/capabilities/airconditioner.py
@@ -210,14 +210,20 @@ def _humidity(rep):
     (51% observed, matching what the same unit's cloud integration reported at
     that moment), then zeroes the field and switches Air monitoring back off by
     itself. So 0 reads as "not measuring" and is reported as unknown rather than
-    as 0% humidity, which would poison long-term history -- which is also why
-    the boards that do have fivepercentHumidity read a permanent 0 here.
+    as 0% humidity, which would poison long-term history.
+
+    That zero-as-"not measuring" carve-out is specific to the ARTIK051
+    fallback field's hardware quirk -- every other board's fivepercentHumidity
+    has never been documented getting stuck at zero, and collapsing a
+    genuine 0% reading there to unknown is a regression, not a safeguard
+    (issue #160). So fivepercentHumidity passes 0 through unchanged; only the
+    humidity fallback applies the zero-collapse.
     """
-    for field in ('x.com.samsung.da.fivepercentHumidity',
-                  'x.com.samsung.da.humidity'):
-        if field in rep:
-            value = _num(rep[field])
-            return value if value else None
+    if 'x.com.samsung.da.fivepercentHumidity' in rep:
+        return _num(rep['x.com.samsung.da.fivepercentHumidity'])
+    if 'x.com.samsung.da.humidity' in rep:
+        value = _num(rep['x.com.samsung.da.humidity'])
+        return value if value else None
     return None
 
 
diff --git a/tests/test_airconditioner_capabilities.py b/tests/test_airconditioner_capabilities.py
index f513be7..8bbb1d1 100644
--- a/tests/test_airconditioner_capabilities.py
+++ b/tests/test_airconditioner_capabilities.py
@@ -415,3 +415,14 @@ def test_humidity_falls_back_to_the_plain_field_where_five_percent_is_absent():
     assert desc.rep_fn({'x.com.samsung.da.humidity': '51'}) == 51.0
     assert desc.rep_fn({'x.com.samsung.da.humidity': '0'}) is None
     assert desc.rep_fn({}) is None
+
+
+def test_humidity_five_percent_field_passes_a_genuine_zero_through():
+    """issue #160: fivepercentHumidity's zero-as-"not measuring" carve-out
+    (added in #146 to cover ARTIK051's plain humidity field) was
+    over-applied to fivepercentHumidity too, silently turning a real 0%
+    reading on every other AC board into unknown. Only the humidity
+    fallback field collapses 0 -- fivepercentHumidity's 0 is a real
+    reading."""
+    desc = airconditioner.HUMIDITY.entities[0]
+    assert desc.rep_fn({'x.com.samsung.da.fivepercentHumidity': '0'}) == 0.0