Distributed indoor air quality control module and method

A indoor air quality (IAQ) control module for a zone of a building, the building having an HVAC system with a blower for supplying supply air to the zone via a supply air duct, and for drawing return air from the zone via a return air duct, the HVAC system further having one or more air control valves that control an amount of supply air that is supplied to the zone via the supply air duct and/or an amount of return air drawn from the zone via the return air duct, the air quality control module comprising:

• at least one sensor;
• a first pressure tap configured to be fluidly coupled to the supply air duct of the HVAC system for receiving a supply air sample from the supply air duct under pressure created by the blower of the HVAC system, the air quality control module directing the supply air sample, while still under pressure created by the blower of the HVAC system, past the at least one sensor and to an exhaust vent, the at least one sensor configured to sense a first air parameter of the supply air sample before the supply air sample exits through the exhaust vent;
• a second pressure tap configured to be fluidly coupled to the return air duct of the HVAC system for receiving a return air sample from the return air duct under pressure created by the blower of the HVAC system, the air quality control module directing the return air sample, while still under pressure created by the blower of the HVAC system, past the at least one sensor and to the exhaust vent, the at least one sensor configured to sense the first air parameter of the return air sample before the return air sample exits through the exhaust vent;
• a controller for causing the air quality control module to alternate between sensing the first air parameter of the supply air sample and sensing the first air parameter of the return air sample;
• the controller determining a measure that is related to a differential between the sensed first air parameter of the supply air sample and the sensed first air parameter of the return air sample;
• and
• the controller outputting one or more control signals to an air valve controller that controls the one or more air control valves, the one or more control signals based, at least in part, on the measure related to the differential between the sensed first air parameter of the supply air sample and the sensed first air parameter of the return air sample.

A method for sensing one or more air parameters of a zone of a building HVAC system having a blower for providing supply air and for drawing return air from the zone, the method comprising:

• obtaining a supply air sample from the supply air that is supplied to the zone using a pressure created by the blower of the building HVAC system;
• obtaining a return air sample from the return air that is draw from the zone also using the pressure created by the blower of the building HVAC system;
• sensing an air parameter of the supply air sample using a first sensor;
• subsequently sensing the air parameter of the return air sample using the first sensor;
• determining at least one differential air parameter value using the sensed air parameter of the supply air sample and the sensed air parameter of the return air sample;
• and
• providing an environmental air quality signal that is based, at least in part, on the differential air parameter value.

A indoor air quality (IAQ) control module for a zone of a building, the building having an HVAC system with a blower for supplying supply air to the zone and for drawing return air from the zone, the air quality control module comprising:

• at least one sensor;
• a first pressure tap for receiving a first air sample of air entering the zone under pressure created by the blower of the HVAC system, the air quality control module directing the first air sample, while still under pressure created by the blower of the HVAC system, past the at least one sensor and to a vent, the at least one sensor configured to sense a first air parameter of the first air sample before the first air sample exits through the vent;
• a second pressure tap for receiving a second air sample from air leaving the zone using a pressure created by the blower of the HVAC system, the air quality control module directing the second air sample, while still under pressure created by the HVAC system and/or the pump, past the same at least one sensor and to the vent, the at least one sensor configured to sense the same first air parameter of the second air sample before the second air sample exits through the vent;
• a third pressure tap for receiving a third air sample from air within the zone using a pressure created by the blower of the HVAC system and/or a pump, the air quality control module directing the third air sample, while still under pressure created by the HVAC system and/or the pump, past the same at least one sensor and to the vent, the at least one sensor configured to sense the same first air parameter of the third air sample before the third air sample exits through the vent;
• a controller for causing the air quality control module to alternate between sensing the first air parameter of the first air sample, sensing the first air parameter of the second air sample, and sensing the first air parameter of the third air sample;
• and
• the controller outputting a measure that is related to a differential between the sensed first air parameter of the first air sample and the sensed first air parameter of the second air sample and/or a measure that is related to a differential between the sensed first air parameter of the first air sample and the sensed first air parameter of the third air sample.