Abstract: An indoor air quality (IAQ) control module may be provided for sensing and controlling the indoor environmental quality (IEQ) of a zone in a building. The IAQ control module may receive a supply air sample from a supply vent and a return air sample from a return vent, where the air samples are taken using the pressure created by a blower within the HVAC system. The IAQ control module may then compute a differential value for each of the sensed one or more air parameters and generate a control signal or command based on at least the differential value(s). The IAQ control module may then communicate the control signal to an airflow control device to control the airflow to and/or from the zone.

Abstract: An indoor air quality (IAQ) control module may be provided for sensing and controlling the indoor environmental quality (IEQ) of a zone in a building. The IAQ control module may receive a supply air sample from a supply vent and a return air sample from a return vent, where the air samples are taken using the pressure created by a blower within the HVAC system. The IAQ control module may then compute a differential value for each of the sensed one or more air parameters and generate a control signal or command based on at least the differential value(s). The IAQ control module may then communicate the control signal to an airflow control device to control the airflow to and/or from the zone.

Abstract: Method and apparatus for testing the operation of an alarm for a ventilated enclosure, such as a fume hood or bio-safety cabinet. Flow of gas being exhausted from the enclosure may be adjusted to a known value below or above a threshold value at which the alarm provides an indication that flow is unacceptably low or high. Adjustment of flow to the known value may be performed without requiring a manual measurement of flow, e.g., by performing a traverse in a duct leading from the enclosure.