System and method for determining air quality characteristic of enclosed volume

Abstract

Disclosed is a heating, ventilation and air-conditioning (HVAC) system for determining a characteristic air quality recovery score of a pollutant in an enclosed volume, comprising a processor configured to obtain pollutant data comprising a plurality of datapoints, the plurality of datapoints indicative of a pollutant concentration of the pollutant over different times; identify an event comprising a sub-range of datapoints from the plurality of datapoints, the event comprising at least one datapoint which satisfies a predetermined criterion of maxima or minima; determine that the event is of a decay event type which follows a pollutant decay pattern; determine a pollutant decay characteristic from the event; and determine the characteristic air quality recovery score of the pollutant based on the pollutant decay characteristic. Further disclosed is a method for operating the HVAC system, and a processor for the HVAC system.

1 . A heating, ventilation and air-conditioning (HVAC) system for determining a characteristic air quality recovery score of a pollutant in an enclosed volume, comprising a processor configured to:
 obtain pollutant data comprising a plurality of datapoints, the plurality of datapoints indicative of a pollutant concentration of the pollutant over different times;   identify an event comprising a sub-range of datapoints from the plurality of datapoints, the event comprising at least one datapoint which satisfies a predetermined criterion of maxima or minima;   determine that the event is of a decay event type which follows a pollutant decay pattern;   determine a pollutant decay characteristic from the event; and   determine the characteristic air quality recovery score of the pollutant based on the pollutant decay characteristic.   
     
     
         2 . The system of  claim 1 , wherein determining that the event is of the decay event type which follows the pollutant decay pattern comprises determining a first increase in the pollutant concentration of the pollutant from a current pollutant data. 
     
     
         3 . The system of  claim 2 , wherein determining the characteristic air quality recovery score based on the pollutant decay characteristic comprises:
 calculating a plurality of event air quality recovery scores; and   determining the characteristic air quality recovery score based on the plurality of event air quality recovery scores.   
     
     
         4 . The system of  claim 3 , wherein determining the characteristic air quality recovery score comprises calculating a statistical measure of the plurality of event air quality recovery scores. 
     
     
         5 . The system of  claim 3 , wherein determining the pollutant decay characteristic from the event comprises:
 determining a first point having a first maximum, the first point corresponding to the determined first increase in the pollutant concentration of the pollutant from the current pollutant data; and   determining a second point having a first minimum, the second point corresponding to a first decrease determined in the pollutant concentration of the pollutant from the first point.   
     
     
         6 . The system of  claim 5 , wherein determining an event air quality recovery score of the pollutant based on the pollutant decay characteristic comprises calculating a first parameter based on the first point having the first maximum and the second point having the first minimum. 
     
     
         7 . The system of  claim 6 , wherein determining the pollutant decay characteristic from the event further comprises:
 determining a third point having a second maximum, the third point corresponding to a second increase determined in the pollutant concentration of the pollutant from the second point; and   determining a fourth point having a second minimum, the fourth point corresponding to a second decrease determined in the pollutant concentration of the pollutant from the third point.   
     
     
         8 . The system of  claim 7 , wherein determining the event air quality recovery score of the pollutant based on the pollutant decay characteristic further comprises:
 calculating a second parameter based on the third point having the second maximum and the fourth point having the second minimum; and   calculating a mean of the first parameter and the second parameter.   
     
     
         9 . The system of  claim 1 , further comprising at least one sensor, for detecting an occupancy of the enclosed volume,
 wherein the processor is in data communication with the at least one sensor, and is further configured to:
 obtain, from the at least one sensor, the occupancy of the enclosed volume; 
 compare the characteristic air quality recovery score with a predetermined threshold air quality recovery score; and 
 adjust at least one operating parameter of the system based on said comparison of the characteristic air quality recovery score with the predetermined threshold air quality recovery score, and/or the occupancy of the enclosed volume. 
   
     
     
         10 . The system of  claim 9 , further comprising a scheduler for storing schedule data indicative of a scheduled use of the enclosed volume,
 wherein the processor is in data communication with the scheduler, and is further configured to:
 obtain, from the scheduler, a time of the scheduled use of the enclosed volume based on the scheduled data; 
 determine a time slot, indicative of a time difference between a current time and the time of the scheduled use of the enclosed volume; 
 calculate a duration required for the pollutant concentration to reach a predetermined threshold, based on the characteristic air quality recovery score; 
 determine if the duration is within the time slot; and 
 adjust the at least one operating parameter of the system based on the determination that the duration is within the time slot. 
   
     
     
         11 . The system of  claim 10 , wherein adjusting the at least one operating parameter of the system comprises adjusting an air flow of a ventilation device, the ventilation device configured to inject fresh air into the enclosed volume and/or to increase a clearance rate of the pollutant from the enclosed volume. 
     
     
         12 . The system of  claim 1 , wherein the pollutant is carbon dioxide. 
     
     
         13 . A control device for a HVAC system, the control device comprising a processor configured to determine a characteristic air quality recovery score of a pollutant in an enclosed volume, the processor being in data communication with a memory having instructions stored therein, the instructions, when executed by the processor, causes the processor to:
 obtain pollutant data comprising a plurality of datapoints, the plurality of datapoints indicative of a pollutant concentration of the pollutant over different times;   identify an event comprising a sub-range of datapoints among the plurality of datapoints, the event comprising at least one datapoint which satisfies a predetermined criterion of maxima or minima;   determine that the event is of a decay event type which follows a pollutant decay pattern;   determine a pollutant decay characteristic from the event; and   determine the characteristic air quality recovery score of the pollutant based on the pollutant decay characteristic.   
     
     
         14 . A method for determining a characteristic air quality recovery score of a pollutant in an enclosed volume, comprising providing a processor for:
 obtaining pollutant data comprising a plurality of datapoints, the plurality of datapoints indicative of a pollutant concentration of the pollutant over different times;   identifying an event comprising a sub-range of datapoints among the plurality of datapoints, the event comprising at least one datapoint which satisfies a predetermined criterion of maxima or minima;   determining that the event is of a decay event type which follows a pollutant decay pattern;   determining a pollutant decay characteristic from the event; and   determining the characteristic air quality recovery score of the pollutant based on the pollutant decay characteristic.   
     
     
         15 . The method of  claim 14 , wherein determining that the event is of the decay event type which follows the pollutant decay pattern comprises determining a first increase in the pollutant concentration of the pollutant from a current pollutant data. 
     
     
         16 . The method of  claim 15 , wherein determining the characteristic air quality recovery score based on the pollutant decay characteristic comprises:
 calculating a plurality of event air quality recovery scores; and   determining the characteristic air quality recovery scores based on the plurality of event air quality recovery scores.   
     
     
         17 . The method of  claim 16 , wherein determining the pollutant decay characteristic from the event comprises:
 determining a first point having a first maximum, the first point corresponding to the determined first increase in the pollutant concentration of the pollutant from the current pollutant data; and   determining a second point having a first minimum, the second point corresponding to a first decrease determined in the pollutant concentration of the pollutant from the first point.   
     
     
         18 . The method of  claim 17 , wherein determining an event air quality recovery score of the pollutant based on the pollutant decay characteristic comprises calculating a first parameter based on the first point having the first maximum and the second point having the first minimum. 
     
     
         19 . The method of  claim 18 , wherein determining the pollutant decay characteristic from the event further comprises:
 determining a third point having a second maximum, the third point corresponding to a second increase determined in the pollutant concentration of the pollutant from the second point; and   determining a fourth point having a second minimum, the fourth point corresponding to a second decrease determined in the pollutant concentration of the pollutant from the third point.   
     
     
         20 . The method of  claim 19 , wherein determining the event air quality recovery score of the pollutant based on the pollutant decay characteristic further comprises:
 calculating a second parameter based on the third point having the second maximum and the fourth point having the second minimum; and   calculating a mean of the first parameter and the second parameter.