4 inch svara lo carbon kitchen bathroom bluetooth fan ip44 introducing the svara extractor fan by vent axia the uks first app controlled unitary extractor fan all modes of operation the fan can be set with the bluetooth enabled app such as continuous or intermittent operation timer duration and humidistat triggering the fan can operate at a background speed with 10 ls extraction then when the sensor is triggered it can increase to 19 ls if the humidity then rises rapidly ie when