Abstract: A method of controlling a concentration or range of concentrations of a liquid or gas in an enclosure is provided. The method includes positioning an injection station within the enclosure. the injection station includes a liquid or gas source, a sprayer assembly and a system that delivers the liquid or gas from the liquid or gas source to the sprayer assembly. A concentration level of the liquid or gas in the environment surrounding the injection station is monitored using a sensor and the sensor providing a signal indicative of the concentration level to a controller. The controller controls the flow of the liquid or gas to the sprayer assembly based on the signal.

Abstract: A method of controlling a concentration or range of concentrations of a liquid or gas in an enclosure is provided. The method includes positioning an injection station within the enclosure, the injection station includes a liquid or gas source, a sprayer assembly and a system that delivers the liquid or gas from the liquid or gas source to the sprayer assembly. A concentration level of the liquid or gas in the environment surrounding the injection station is monitored using a sensor and the sensor providing a signal indicative of the concentration level to a controller. The controller controls the flow of the liquid or gas to the sprayer assembly based on the signal.

Abstract: A fan powered by a controlled external energy source and a flow measurement device measure the airflow exiting or entering grilles/registers of an HVAC system without impeding the airflow being measured. A flow straightening element is preferably employed to overcome any effects of a non-uniform or swirled airflow profile on the fan. Preferably, the RPM of the fan is measured to determine the airflow. The RPM/flow calibration of the fan is insensitive to pressure differentials or the fan is a pressure-sensitive fan submitted to appropriate pressure differentials. Alternatively, the voltage or current supplied to the external energy source is used to determine the airflow. Finally, the pressure differential across the flow straightening element can be measured to determine airflow, eliminating the impact of pressure differential across the flow measurement device and fan.

Abstract: A fan powered by a controlled external energy source and a flow measurement device measure the airflow exiting or entering grilles/registers of an HVAC system without impeding the airflow being measured. A flow straightening element is preferably employed to overcome any effects of a non-uniform or swirled airflow profile on the fan. Preferably, the RPM of the fan is measured to determine the airflow. The RPM/flow calibration of the fan is insensitive to pressure differentials or the fan is a pressure-sensitive fan submitted to appropriate pressure differentials. Alternatively, the voltage or current supplied to the external energy source is used to determine the airflow. Finally, the pressure differential across the flow straightening element can be measured to determine airflow, eliminating the impact of pressure differential across the flow measurement device and fan.

Abstract: A fan powered by a controlled external energy source and a flow measurement device measure the airflow exiting or entering grilles/registers of an HVAC system without impeding the airflow being measured. A flow straightening element is preferably employed to overcome any effects of a non-uniform or swirled airflow profile on the fan. Preferably, the RPM of the fan is measured to determine the airflow. The RPM/flow calibration of the fan is insensitive to pressure differentials or the fan is a pressure-sensitive fan submitted to appropriate pressure differentials. Alternatively, the voltage or current supplied to the external energy source is used to determine the airflow. Finally, the pressure differential across the flow straightening element can be measured to determine airflow, eliminating the impact of pressure differential across the flow measurement device and fan.