Feedback loop control of aerosolized compound within a human occupiable space

1. A method of maintaining a desired level of an aerosolized compound within a human occupiable space, the method comprising:

operating a diffusion device to diffuse a compound from a scented liquid source into a human occupiable space to be treated throughout a treatment period in which the human occupiable space is subjected to uncontrolled ventilation rate conditions arising from HVAC activity and from entry/exit activity of human occupants moving into and out of the human occupiable space;

sensing a concentration of the compound within the human occupiable space to be treated throughout a treatment period in which the human occupiable space is subjected to uncontrolled ventilation rate conditions arising from HVAC activity and from entry/exit activity of human occupants moving into and out of the human occupiable space; and

altering the operation of the diffusion device based on the concentration of the compound sensed within the human occupiable space if necessary to achieve a desired concentration of compound within the human occupiable space to be treated.

2. The method of claim 1 , further comprising:

repeating the sensing and the altering periodically during the treatment period to maintain the desired concentration of the compound within the human occupiable space to be treated.

3. The method of claim 1 , further comprising:

monitoring other activity within the human occupiable space to be treated; and

altering the operation of the diffusion device based on the monitoring of such other activity within the human occupiable space to be treated.

4. The method of claim 3 wherein monitoring other activity within the human occupiable space includes monitoring one or more entries or exits of human occupants from the human occupiable space, and wherein altering the operation of the diffusion device includes altering the operation of the diffusion device based at least in part on the monitoring of the one or more entries or exits of the human occupants.

5. The method of claim 3 wherein monitoring the other activity within the human occupiable space includes monitoring HVAC activity, and wherein altering the operation of the diffusion device includes altering the operation of the diffusion device based at least in part on the monitoring of the HVAC activity.

6. The method of claim 3 wherein monitoring other activity within the human occupiable space and altering the operation of the diffusion device includes anticipating changes in concentration of the compound from such other activity and responding to such other activity before the other activity has an adverse impact on the concentration of the compound in the human occupiable space.

7. The method of claim 1 wherein sensing the concentration of the compound within the human occupiable space to be treated includes observing low-frequency oscillations that correlate with HVAC activity and observing high-frequency oscillations that correlate with entry/exit activity.

8. The method of claim 1 wherein altering the operation of the diffusion device includes controlling an aerosol generation rate to compensate for a baseline variability associated with ventilation rate variability.

9. A liquid diffusion system for treating a human occupiable space that is subjected to uncontrolled ventilation rate conditions arising from HVAC activity and from entry/exit activity of human occupants moving into and out of the human occupiable space with a compound aerosolized from a scented liquid, the liquid diffusion system comprising:

a liquid diffusion device including a cartridge filled with the scented liquid;

a sensor in fluid communication with the air in the human occupiable space to be treated, the sensor configured to sense the concentration of the compound within the air of the human occupiable space to be treated irrespective of the presence of human occupants throughout a treatment period in which the human occupiable space is subjected to uncontrolled ventilation rate conditions arising from HVAC activity and entry/exit activity of human occupants moving into and out of the human occupiable space; and

a control system for operating the liquid diffusion device to diffuse the compound from the scented liquid into the occupiable space to be treated, the control system configured to alter the operation of the liquid diffusion device based on the concentration of the compound sensed by the sensor within the human occupiable space to be treated and a desired concentration of that compound.

10. The liquid diffusion device of claim 9 wherein the control system includes a feedback loop for the operation of the liquid diffusion device, with the sensor periodically sensing the concentration of the compound and the control system altering operation of the liquid diffusion device based on each sensed concentration of the compound sensed by the sensor.

11. The liquid diffusion device of claim 9 wherein the control system further comprises at least one additional sensor to sense activity within the human occupiable space to be treated and to alter the operation of the liquid diffusion device based on such activity within the human occupiable space sensed by the at least one additional sensor.