WO2024259718A1

WO2024259718A1 - Methods for evaluating indoor air quality and controlling a building control system in accordance with the indoor air quality

Info

Publication number: WO2024259718A1
Application number: PCT/CN2023/101999
Authority: WO
Inventors: Bin Dong; Bhavesh S. Gupta; Neerja BAKSHI; Qinghua Wang; Jie Gao; Jianguo Zhao; Shidian XU; Yaolin LIU
Original assignee: Honeywell International Inc
Current assignee: Honeywell International Inc
Priority date: 2023-06-23
Filing date: 2023-06-23
Publication date: 2024-12-26
Anticipated expiration: 2025-12-23
Also published as: EP4710052A1

Abstract

An IAQ (Indoor Air Quality) score may be determined for a building space. The IAQ score may be based upon one or more numerical air quality parameter values. Once determined, the IAQ score may be displayed. In some instances, a building control system such as a Heating, Ventilating and Air Conditioning (HVAC) system may be operated in accordance with the determined IAQ score. For example, ventilation may be increased in order to improve the IAQ score.

Description

METHODS FOR EVALUATING INDOOR AIR QUALITY AND CONTROLLING A BUILDING CONTROL SYSTEM IN ACCORDANCE WITH THE INDOOR AIR QUALITY

TECHNICAL FIELD

The present disclosure relates to methods and systems for operating a Heating, Ventilating and Air Conditioning (HVAC) system.

BACKGROUND

HVAC systems provide conditioned air for heating and cooling the interior of a building. Some HVAC systems also can provide fresh air ventilation into the building while exhausting an equivalent amount of inside air. Such fresh air ventilation is useful in reducing contaminates produced in the building. However, there are often costs involved in conditioning the fresh air before it can be deployed in the building. For example, in the winter, the cold fresh air must typically be heated by the HVAC system, and in some cases, humidity must be added. Likewise, in the summer, the warm fresh air must typically be cooled by the HVAC system, and in some cases, humidity must be removed. Thus, to reduce operating costs, it is often desirable to minimize the ventilation rate while still adequately ventilating the building given the current contaminates or expected contaminates in the building.

Under some conditions, such as during a pandemic, it may be desirable to prioritize an increased ventilation rate over energy costs to help reduce the spread of pathogens within the building. Under these conditions, if the ventilation rate is set too high, given the current indoor and outdoor conditions, the HVAC system may lack the heating and/or cooling capacity to adequately condition the incoming fresh air while still maintaining occupant comfort in the building. What would be desirable are improved methods for determining indoor air quality and operating a building control system in accordance with the determined indoor air quality.

SUMMARY

The present disclosure relates to methods and systems for operating a Heating, Ventilating and Air Conditioning (HVAC) system. An example may be found in a method of determining a IAQ (Indoor Air Quality) score that falls along a IAQ score range based on a measured air quality parameter value for air associated with a building space. The illustrative method includes storing a numerical IAQ score range for each of two or more IAQ score sub-ranges along the IAQ score range and storing a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more IAQ score sub-ranges. The illustrative method includes identifying which of the two or more air quality parameter sub-ranges that the measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value and identifying the IAQ score sub-range of the two or more IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, resulting in an identified one of the two or more IAQ score sub-ranges along the IAQ score range. The IAQ score for the building space is determined based at least in part on the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, the numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and the measured air quality parameter value. In some cases, the illustrative method includes controlling a building control system that is servicing the building space based at least in part on the first IAQ score of the building space. The air quality parameter may correspond to, for example, CO₂ concentration, Volatile Organic Compound (VOC) concentration, Particular Matter (PM) concentration, humidity, CO concentration and/or any other suitable air quality parameter.

Another example may be found in a method for determining a composite IAQ score along a composite IAQ score range based on a plurality of measured air quality parameter values for air associated with a building space. The illustrative method includes storing a composite numerical IAQ score range for each two or more composite IAQ score sub-ranges along a composite IAQ score range. The illustrative method includes, for each of the plurality of measured air quality parameter values, storing a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more composite IAQ score sub-ranges, identifying which of the two or more air quality parameter sub-ranges that the corresponding measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, identifying the composite IAQ score sub-range of the two or more composite IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, resulting in an identified one of the two or more composite IAQ score sub-ranges along the composite IAQ score range that correspond to the corresponding measured air quality parameter value, and determining an IAQ score for each of the plurality of measured air quality parameter values based at least in part on the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, the composite numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and the corresponding measured air quality parameter value. The illustrative method includes determining the composite IAQ score along the composite IAQ score range for air in the building space based at least in part on the IAQ score determined for each of the plurality of measured air quality parameter values, and displaying the composite IAQ score on a display.

Another illustrative example may be found in a method for updating an IAQ score of a building space. The illustrative method includes determining one or more IAQ scores for the building space based on one or more measured air quality parameter, wherein each of the one or more IAQ scores falls within one of a high, moderate or unhealthy category, determining when one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time, and updating a displayed IAQ category corresponding to at least one of the IAQ scores only after the one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time.

The preceding summary is provided to facilitate an understanding of some of the innovative features unique to the present disclosure and is not intended to be a full description. A full appreciation of the disclosure can be gained by taking the entire specification, claims, figures, and abstract as a whole.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure may be more completely understood in consideration of the following description of various examples in connection with the accompanying drawings, in which:

Figure 1 is a schematic block diagram of an illustrative building system;

Figures 2A and 2B are flow diagrams that together show an illustrative method for determining a first IAQ score;

Figures 3A and 3B are flow diagrams that together show an illustrative method for determining a composite IAQ score;

Figure 4 is a flow diagram showing an illustrative method for updating an IAQ score of a building space;

Figures 5 and 6 are screen showing illustrative dashboards; and

Figure 7 is a perspective view of an illustrative wall-mountable building control device showing an illustrative IAQ score.

While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular examples described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

DESCRIPTION

The following description should be read with reference to the drawings, in which like elements in different drawings are numbered in like fashion. The drawings, which are not necessarily to scale, depict examples that are not intended to limit the scope of the disclosure. Although examples are illustrated for the various elements, those skilled in the art will recognize that many of the examples provided have suitable alternatives that may be utilized.

All numbers are herein assumed to be modified by the term “about” , unless the content clearly dictates otherwise. The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) .

As used in this specification and the appended claims, the singular forms “a” , “an” , and “the” include the plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

It is noted that references in the specification to “an embodiment” , “some embodiments” , “other embodiments” , etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is contemplated that the feature, structure, or characteristic is described in connection with an embodiment, it is contemplated that the feature, structure, or characteristic may be applied to other embodiments whether or not explicitly described unless clearly stated to the contrary.

Figure 1 is a schematic block diagram of an illustrative system 10. The illustrative system 10 includes a plurality of IAQ (Indoor Air Quality) sensors 12 that are located within a building space 14. The building space 14 may represent a facility, or a part of a facility such as a floor or section of a building. The IAQ sensors 12, individually labeled as 12a, 12b and 12c, may each represent any of a variety of different IAQ sensors, such as but not limited to carbon dioxide sensors, particulate matter sensors, volatile organic compound sensors, carbon monoxide sensors, gas sensors, humidity sensors and/or any other suitable indoor air quality sensor. A building control system 16 is configured to control the building space 14. In some instances, the building control system 16 may include a Heating, Ventilating and Air Conditioning (HVAC) system, and/or may include HVAC system components.

The IAQ sensors 12 are operably coupled with a controller 18 that receives signals from the IAQ sensors 12 and is configured to output commands to the building control system 16. In some instances, the controller 18 may be configured to command operation of the building control system 16 in response to the signals received from the IAQ sensors 12, such as increasing ventilation (e.g. opening or further opening an outside air damper) when the IAQ sensors 12 indicate undesired levels of various pollutants. In some instances, the controller 18 may be configured to utilize the signals from the IAQ sensors 12 to determine one or more IAQ scores for the building space 14. The controller 18 may be configured to command operation of the building control system 16 in response to the determined one or more IAQ scores for the building space 14 in order to improve environmental conditions within the building space 14. In the example shown, the controller 18 includes a memory 19.

While the controller 18 and the building control system 16 are shown as being distinct, it will be appreciated that in some instances the controller 18 may be manifested as part of the building control system 16. In some instances, at least some of the functionality of the building control system 16 and/or the controller 18 may be disposed locally within the building space 14, such as within an edge computer/controller, and at least some of the functionality of the building control system 16 and/or the controller 18 may be remote from the building space 14, and may be manifested within a cloud-based server, for example. These are just examples.

In some instances, the building control system 16 may include or otherwise may be operably coupled with a display 20. The display 20 may be part of a computer, a mobile device, a wall mountable device such as a wall mountable sensor or thermostat, or any other suitable device. In some instances, the display 20 may be used to display IAQ scores for the building space 14. In some instances, the system 10 may include a building control device 22 having a display 24. In some cases, the building control device 22 may be an IAQ sensor. In some cases, the building control device 22 may represent a thermostat or other HVAC controller, for example. In some instances, the building control device 22 may be a dedicated device configured to display an IAQ score on the display 24 and/or display a graphical representation of the IAQ score such as an IAQ category. In some instances, the building control device 22 itself may include at least some of the functionality of the controller 18, and may itselfbe configured to determine the IAQ score. In some instances, while the controller 18 is shown as a distinct element, the controller 18 may be part of the building control device 22, or even part of the building control system 16.

In some instances, the controller 18 and/or the building control device 22 may be configured to store a numerical IAQ score range for each of two or more IAQ score sub-ranges along the IAQ score range and to store a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more IAQ score sub-ranges. An example of the IAQ score sub-ranges (see row labeled IAQ Score) and the air quality parameters sub-ranges (see rows labeled VOC, CO2 and PM2.5) are shown in Table 1 below.

Table 1

The IAQ score sub-ranges are detailed in the row labeled IAQ Score, and the air quality parameters sub-ranges are detailed in the rows labeled VOC, CO2 and PM2.5.

Each of the air quality parameter concentration values may be provided by one or more of the IAQ sensors 12. The controller 18 and/or the building control device 22 may be configured to identify which of the two or more air quality parameter sub-ranges that the measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, and to identify the IAQ score sub-range of the two or more IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, resulting in an identified one of the two or more IAQ score sub-ranges along the IAQ score range.

In some instances, the controller 18 and/or the building control device 22 may be configured to determine the IAQ score for the building space based at least in part on the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, the numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and/or the measured air quality parameter value. In some instances, the controller 18 may be configured to display the IAQ score on the display 24 of the wall mountable building control device 22. In some instances, the controller 18 and/or the building control device 22 may be configured to display the IAQ score on a dashboard that is displayed on the display 20 of the building control system 16.

In some instances, the controller 18 and/or the building control device 22 may be configured to define the numerical IAQ score range for each of the two or more IAQ score sub-ranges along the IAQ score range between a corresponding IAQ low score value and a corresponding IAQ high score value and to define the numerical air quality parameter value range for each of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value between a corresponding air quality parameter low value and a corresponding air quality parameter high value. In some instances, the controller 18 and/or the building control device 22 may be configured to determine the IAQ score for the building space 14 based at least in part on one or more of the air quality parameter low value and the air quality parameter high value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, the IAQ low score value and the IAQ high score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and the measured air quality parameter value.

As an example, the controller 18 and/or the building control device 22 may be configured to determine the IAQ score for the building space 14 using the following equation:

where,

IAQ Score=the IAQ score for the building space,

C=the measured air quality parameter value,

BP_LO=the air quality parameter low value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value,

BP_HI=the air quality parameter high value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value,

I_LO=the IAQ low score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and

I_HI=the IAQ high score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range.

In some instances, the numerical air quality parameter value range for each of two or more air quality parameter sub-ranges are user programmable. In some instances, the measured air quality parameter value may include one of CO₂, VOC, and PM. In some instances, the IAQ score range goes between 0 to 100, with a higher IAQ score representing a better air quality for the air in the building space. The two or more IAQ score sub-ranges may include three or less IAQ score sub-ranges (e.g. Good, Moderate and Unhealthy in Table 1) .

In some instances, the controller 18 and/or the building control device 22 may be configured to repeatedly receive raw measured air quality parameter values from a air quality parameter sensor, and to filter the raw measured air quality parameter values using a filter to produce the measured air quality parameter value. As an example, the filter may be an exponential moving average (EMA) filter. As another example, the filter may utilize the following equation:
S_t=α·Y_t+ (1-α) ·S_t-1

where

S_t represents a current value;

α is a numerical value that is user-selectable, and in this case is equal to 0.3

Y_t represents a measured value; and

S_t-1 represents a previous value.

In some instances, the controller 18 and/or the building control device 22 may be configured to determine a composite IAQ score along a composite IAQ score range based on a plurality of measured air quality parameter values (e.g. VOC, CO2 and PM2.5 of Table 1) for air associated with a building space. In some instances, the composite IAQ score may be based upon two or more different air quality parameters. The controller 18 and/or the building control device 22 may be configured to store a composite numerical IAQ score range for each two or more composite IAQ score sub-ranges along a composite IAQ score range. For each of the plurality of measured air quality parameter values, the controller 18 and/or the building control device 22 may be configured to store a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more composite IAQ score sub-ranges. The controller 18 and/or the building control device 22 may be configured to identify which of the two or more air quality parameter sub-ranges that the corresponding measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value and to identify the composite IAQ score sub-range of the two or more composite IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, resulting in an identified one of the two or more composite IAQ score sub-ranges along the composite IAQ score range that correspond to the corresponding measured air quality parameter value.

The controller 18 and/or the building control device 22 may be configured to determine an IAQ score for each of the plurality of measured air quality parameter values based at least in part on one or more of the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, the composite numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and the corresponding measured air quality parameter value. The controller 18 and/or the building control device 22 may be configured to determine the composite IAQ score along the composite IAQ score range for air in the building space based at least in part on the IAQ score determined for each of the plurality of measured air quality parameter values and to display the composite IAQ score on a display such as the display 20 or the display 24. In some instances, the controller 18 and/or the building control device 22 may be configured to send command signals to the building control system 16 based at least in part on the composite IAQ score.

In some instances, the controller 18 and/or the building control device 22 may be configured to determine when the composite IAQ score changes by at least a dead band amount for at least a predetermined time period and to change a displayed IAQ category on the display when the composite IAQ score changes by at least the dead band amount for at least the predetermined time period. In some instances, the dead band may be a user-adjustable value. The dead band and/or predetermined time period may serve to reduce hysteresis that might otherwise occur in the displayed IAQ category.

In some instances, the controller 18 and/or the building control device 22 may be configured to update an IAQ score of the building space 14. As an example, the controller 18 and/or the building control device 22 may be configured to determine one or more IAQ scores for the building space based on one or more measured air quality parameter, wherein each of the one or more IAQ scores falls within one of a high, moderate or unhealthy category (e.g. see Table 1) . The controller 18 and/or the building control device 22 may be configured to determine when one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time, and to update a displayed IAQ category corresponding to at least one of the IAQ scores only after the one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time. The predetermined time may be user-programmable.

In some instances, the controller 18 and/or the building control device 22 may be configured to determine the composite IAQ score along the composite IAQ score range by determining a worst one of the IAQ scores for each of the plurality of measured air quality parameter values. In some instances, the controller 18 and/or the building control device 22 may be configured to determine the composite IAQ score along the composite IAQ score range by discounting the worst one of the IAQ scores for each of the plurality of measured air quality parameter values based at least in part on which of the composite numerical IAQ score ranges that the IAQ scores for each of the plurality of measured air quality parameter values falls within.

As an example, for a sensor with just a CO2 sensor, say that the concentration of CO2 is 1200, which falls within the Moderate range of Table 1.

So, in the Example shown in Table 1, the I_HI and I_LO are 79 and 40, BP_HI and BP_LO are 1400 and 1001,

Using Equation 1, the air quality score of CO2= (79-40) / (1400-1001) * (1400-1200) +40 =60

In this example, the final air quality score=air quality score of CO2=60.

As another example, for a sensor with a VOC, CO2 and PM2.5 sensor, say that the concentration of VOC is 1024, which falls within the Unhealthy range of Table 1.

So, in the Example shown in Table 1, the I_HI and I_LO are 39 and 0, BP_HI and BP_LO are 9999 and 351,

Using Equation 1, the air quality score of VOC= (39-0) / (9999-351) * (9999-1024) +0= 36

Say also that the concentration of CO2 is 1200, which falls within the Moderate range of Table 1.

Using Equation 1, air quality score of CO2= (79-40) / (1400-1001) * (1400-1200) +40= 60

Say that the concentration of PM2.5 is 4, which falls within the Good range of Table 1.

So, in the Example shown in Table 1, the I_HI and I_LO are 100 and 80, BP_HI and BP_LO are 35 and 0,

Using Equation 1, the air quality score of PM2.5= (100-80) / (35-0) * (35-4) +80=98.

In some instances, if two parameters fall in the Moderate or Unhealthy range, 10 is subtracted from the final air quality score (e.g. from the lowest of the three air quality scores for VOC, CO2 and PM2.5) . That is, the lowest of the three air quality scores for VOC, CO2 and PM2.5 is discounted by 10 to arrive at the final composite air quality score. In this example, the final composite air quality score=min (air quality score of CO2, air quality score of PM2.5, air quality score of VOC) -10=26. If three parameters fall in the Moderate or Unhealthy range, 15 is subtracted from the final air quality score (e.g. from the lowest of the three air quality scores for VOC, CO2 and PM2.5) . That is, the lowest of the three air quality scores for VOC, CO2 and PM2.5 is discounted by 15 to arrive at the final composite air quality score. In this example, the final composite air quality score=min (air quality score of CO2, air quality score of PM2.5, air quality score of VOC) -15=21.

Figures 2A and 2B are flow diagrams that together show an illustrative method 26 of determining a IAQ score that falls along a IAQ score range based on a measured air quality parameter value for air associated with a building space (such as the building space 14) . The method 26 includes storing (such in the memory 19) a numerical IAQ score range for each of two or more IAQ score sub-ranges along the IAQ score range, as indicated at block 28. A numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value are stored, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more IAQ score sub-ranges, as indicated at block 30. An example of such ranges is shown in Table 1.

An identification is made as to which of the two or more air quality parameter sub-ranges that the measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, as indicated at block 32. An identification is made as to the IAQ score sub-range of the two or more IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, resulting in an identified one of the two or more IAQ score sub-ranges along the IAQ score range, as indicated at block 34.

The illustrative method 26 includes determining the IAQ score for the building space, as represented in block 36a in Figure 2A and in block 36b in Figure 2b. In some instances, block 36a and block 36b may each be considered as providing alternatives for determining the IAQ score. Determining the IAQ score for the building space may be based at least in part upon the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, as indicated at block 38a. Determining the IAQ score for the building space may be based at least in part upon the numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range, as indicated at block 40a. Determining the IAQ score for the building space may be based at least in part upon the measured air quality parameter value, as indicated at block 42a.

In some instances, the numerical IAQ score range for each of the two or more IAQ score sub-ranges along the IAQ score range may be defined between a corresponding IAQ low score value and a corresponding IAQ high score value, and the numerical air quality parameter value range for each of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value may be defined between a corresponding air quality parameter low value and a corresponding air quality parameter high value. As shown in Figure 2B, determining the IAQ score for the building space may be based at least in part upon the air quality parameter low value and the air quality parameter high value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, as indicated at block 38b. Determining the IAQ score for the building space may be based at least in part upon the IAQ low score value and the IAQ high score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range, as indicated at block 40b. Determining the IAQ score for the building space may be based at least in part upon the measured air quality parameter value, as indicated at block 42b.

The illustrative method 26 further includes controlling a building control system (such as the building control system 16) that is servicing the building space (such as the building space 14) based at least in part on the IAQ score of the building space, as indicated at block 44. In some instances, the method 26 may further include displaying the first IAQ score on a display (such as the display 24) of a wall mountable building control device (such as the building control device 22) , wherein the wall mountable building control device is part of the building control system, as indicated at block 46. In some instances, the method 26 may further include displaying the IAQ score on a dashboard that is displayed on a display (such as the display 20) of the building control system (such as the building control system 16) .

In some instances, determining the IAQ score for the building space is computed using the following equation:

where,

IAQ Score=the IAQ score for the building space,

C=the measured air quality parameter value,

In some instances, the numerical air quality parameter value range for each of two or more air quality parameter sub-ranges may be user programmable. In some instances, the measured air quality parameter value may include one of CO₂, VOC, and PM. The IAQ score range may go between 0 to 100, with a higher IAQ score representing a better air quality for the air in the building space. In some instances, the two or more IAQ score sub-ranges may include three or less IAQ score sub-ranges. An example may be found in Table 1.

In some instances, the method 26 may further include repeatedly receiving raw measured air quality parameter values (e.g. from a first measure air quality parameter sensor) , as indicated at block 50. The method 26 may further include filtering the raw measured air quality parameter values using a filter to produce the measured air quality parameter value, as indicated at block 52. As an example, the filter may be an exponential moving average (EMA) filter.

Figures 3A and 3B are flow diagrams that together show an illustrative method 54 for determining a composite IAQ score along a composite IAQ score range based on a plurality of measured air quality parameter values for air associated with a building space (such as the building space 14) . The illustrative method 54 includes storing a composite numerical IAQ score range for each two or more composite IAQ score sub-ranges along a composite IAQ score range, as indicated at block 56. A number of actions take place for each of the plurality of measured air quality parameter values, as indicated at block 58. One of the actions includes storing a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more composite IAQ score sub-ranges, as indicated at block 60. One of the actions includes identifying which of the two or more air quality parameter sub-ranges that the corresponding measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, as indicated at block 62. One of the actions includes identifying the composite IAQ score sub-range of the two or more composite IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, resulting in an identified one of the two or more composite IAQ score sub-ranges along the composite IAQ score range that correspond to the corresponding measured air quality parameter value, as indicated at block 64.

Continuing on Figure 3B, one of the actions includes determining an IAQ score for each of the plurality of measured air quality parameter values, as indicated at block 66. Determining an IAQ score is based at least in part on the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, as indicated at block 68. Determining an IAQ score is based at least in part on the composite numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range, as indicated at block 70. Determining an IAQ score is based at least in part on the corresponding measured air quality parameter value, as indicated at block 72. The method 54 includes determining the composite IAQ score along the composite IAQ score range for air in the building space based at least in part on the IAQ score determined for each of the plurality of measured air quality parameter values, as indicated at block 74. The illustrative method 54 includes displaying the composite IAQ score on a display, as indicated at block 76. The composite IAQ score may be displayed on a display of a wall mountable building control device, wherein the wall mountable building control device is operatively coupled to a building control system. The composite IAQ score may be displayed on a dashboard of building control system.

In some instances, the illustrative method 54 may further include controlling a building control system servicing the building space based at least in part on the composite IAQ score, as indicated at block 78. In some instances, the illustrative method 54 may include determining when the composite IAQ score changes by at least a dead band amount for at least a predetermined time period, as indicated at block 80. In some instances, the method 54 may include changing an IAQ category that is displayed on the display when the composite IAQ score changes by at least the dead band amount for at least the predetermined time period, as indicated at block 82.

In some instances, determining the composite IAQ score along the composite IAQ score range may include determining a worst one of the IAQ scores for each of the plurality of measured air quality parameter values. In some instances, determining the composite IAQ score along the composite IAQ score range may include discounting the worst one of the IAQ scores for each of the plurality of measured air quality parameter values based at least in part on which of the composite numerical IAQ score ranges that the IAQ scores for each of the plurality of measured air quality parameter values falls within. The plurality of measured air quality parameters may include two or more of CO₂, VOC, and PM. As an example, if two of the parameters are classified as moderate or unhealthy, a deduction of 10 is applied to the composite IAQ score. If three of the parameters are classified as moderate or unhealthy, a deduction of 15 is applied to the composite IAQ score.

Figure 4 is a flow diagram showing an illustrative method 84 for updating an IAQ score of a building space (such as the building space 14) . The method 84 includes determining one or more IAQ scores for the building space based on one or more measured air quality parameter, wherein each of the one or more IAQ scores falls within one of a high, moderate or unhealthy category, as indicated at block 86. The illustrative method 84 includes determining when one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time, as indicated at block 88. The illustrative method 84 includes updating a displayed IAQ category corresponding to one or more of the IAQ scores only after the one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time, as indicated at block 90. The predetermined time may be user-programmable, for example.

Figures 5 and 6 are screen shots showing illustrative dashboards that may be generated and displayed by the controller 18, for example. Figure 5 shows an illustrative dashboard 92 that provides healthy building information for a number of sites. The dashboard 92 may be considered as an overview. The dashboard 92 includes an overall rating widget 94 that shows how many sites currently have a poor rating, an average rating, a good rating or an excellent rating. The dashboard 92 includes an air quality widget 96, an indoor climate widget 98 and an in-air pathogen compliance widget 100. Each of the widgets 96, 98 and 100 include summary information listing how many sites currently have a poor rating, an average rating, agood rating or an excellent rating with respect to air quality, indoor climate and in-air pathogen compliance, respectively. The dashboard 92 also includes a listing 102 that shows performance by site. It will be appreciated that the listing 102 can be scrolled through, and is not shown in its entirety in Figure 5. The HBT Atlanta HQ is currently rated 5, or excellent, with 5’s across each of air quality, indoor climate and in-air pathogen compliance. This contrasts with Aero Houston HQ, which is currently rated 3, or average, with 3’s for air quality and in-air pathogen compliance and a 5, or excellent, for indoor climate. The air quality ratings of each site may be based, at least in part, on the composite numerical IAQ scores discussed herein.

Figure 6 shows an illustrative dashboard 104 that may be generated and displayed by the controller 18, for example. Figure 6 shows an illustrative dashboard 104 that may be displayed by selecting the Aero Houston HQ from the listing 102 in the dashboard 92 (Figure 5) . The dashboard 104 includes an overall rating widget 106 that shows how many areas of the Aero Houston HQ currently have a poor rating, an average rating, a good rating or an excellent rating. The dashboard 104 includes an air quality widget 108 that shows overall an average score for the site, and indicates that all areas currently meet particulate matter and carbon dioxide guidelines, and that one area is out of range with respect to total volatile organic compounds. An indoor climate widget 110 shows that the overall rating is excellent, with all areas within range for both temperature and humidity.

A listing 112 shows the performance values for each of a number of different areas within the Aero Houston HQ building. In particular, reference line 114 shows current data for conference room 25. It can be seen that the carbon dioxide concentration is 998 ppm, which is just inside the good range, and the TVOC concentration is 350 ppb, which is at the top of the moderate range. Reference line 114 also indicates that the current occupancy count for conference room 25 is a total of 8 people, which is above the occupancy limit for that space of only 6 people. It will be appreciated that the high relative occupancy is likely contributing to the CO₂ value being at the top of the good range and the TVOC value being at the top of the moderate range. Currently, conference room 25 is undergoing 4 air changes per hour, so it may be possible to increase the ventilation rate in order to reduce the CO₂ and TVOC values. Another option may be to reduce the current occupancy. The air quality rating column for each region or area may be based, at least in part, on the composite numerical IAQ scores corresponding to each region or area.

Figure 7 is a perspective view of an illustrative building control device 120. The illustrative building control device 120 may represent an IAQ sensor. In some instances, the building control device 120 may represent a wall mountable thermostat or HVAC controller, for example. In some cases, the building control device 120 may be a dedicated device intended for displaying IAQ data, but this is not required. The illustrative building control device 120 includes a housing 122 defining a front face 124. As shown, the building control device 120 provides several graphical indications of current air quality. The building control device 120 includes a numerical display 126 that shows the current air quality score is 95 out of 100. The building control device 120 also includes a graphical icon 128 that may be configured to provide a graphical representation of the air quality score, such as the composite IAQ score. In some instances, the graphical icon 128 may be a semi-circle, and may be presented in a different color depending on the current air quality score. For example, if the air quality score falls with the “good” range (see Table 1) , the graphical icon 128 may glow green. The graphical icon 128 may glow yellow when the air quality score is “moderate” and red when the air quality score is “unhealthy” . Continuing with the example shown in Table 1, the graphical icon 128 may glow green when the air quality score is between 80 and 100; the graphical icon 128 may glow yellow when the air quality score is between 40 and 79; and the graphical icon 128 may glow red when the air quality score is between 0 and 39. It is contemplated that the building control device 120 may display the current air quality score via the numerical display 126 and/or may display graphical icon 128 that is representative of the current air quality score.

Having thus described several illustrative embodiments of the present disclosure, those of skill in the art will readily appreciate that yet other embodiments may be made and used within the scope of the claims hereto attached. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, arrangement of parts, and exclusion and order of steps, without exceeding the scope of the disclosure. The disclosure’s scope is, of course, defined in the language in which the appended claims are expressed.

Claims

A method of determining a IAQ score that falls along a IAQ score range based on a measured air quality parameter value for air associated with a building space, the method comprising:

storing a numerical IAQ score range for each of two or more IAQ score sub-ranges along the IAQ score range;

storing a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more IAQ score sub-ranges;

identifying which of the two or more air quality parameter sub-ranges that the measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value;

identifying the IAQ score sub-range of the two or more IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value, resulting in an identified one of the two or more IAQ score sub-ranges along the first IAQ score range;

determining the IAQ score for the building space based at least in part on:

the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value;

the numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range;

the measured air quality parameter value; and

controlling a building control system that is servicing the building space based at least in part on the IAQ score of the building space.
The method of claim 1, further comprising displaying the IAQ score on a display of a wall mountable building control device, wherein the wall mountable building control device is part of the building control system.
The method of claim 1, further comprising displaying the IAQ score on a dashboard that is displayed on a display of the building control system.
The method of claim 1, wherein:

the numerical IAQ score range for each of the two or more IAQ score sub-ranges along the IAQ score range is defined between a corresponding IAQ low score value and a corresponding IAQ high score value;

the numerical air quality parameter value range for each of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value is defined between a corresponding air quality parameter low value and a corresponding air quality parameter high value;

wherein determining the IAQ score for the building space is based at least in part on:

the air quality parameter low value and the air quality parameter high value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value;

the IAQ low score value and the IAQ high score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range; and

the measured air quality parameter value.
The method of claim 4, wherein determining the IAQ score for the building space is computed using the following equation:

where,

IAQ Score=the IAQ score for the building space,

C=the measured air quality parameter value,

BP_LO=the air quality parameter low value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value,

BP_HI=the air quality parameter high value that correspond to the identified one of the two or more air quality parameter sub-ranges that correspond to the measured air quality parameter value,

I_LO=the IAQ low score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range, and

I_HI=the IAQ high score value that correspond to the identified one of the two or more IAQ score sub-ranges along the IAQ score range.
The method of claim 1, wherein the numerical air quality parameter value range for each of two or more air quality parameter sub-ranges are user programmable.
The method of claim 1, wherein the measured air quality parameter value comprises one of CO₂, VOC, and PM.
The method of claim 1, wherein the IAQ score range goes between 0 to 100, with a higher IAQ score representing a better air quality for the air in the building space.
The method of claim 1, wherein the two or more IAQ score sub-ranges comprise three or less IAQ score sub-ranges.
The method of claim 1, comprising:

repeatedly receiving raw measured air quality parameter values; and

filtering the raw measured air quality parameter values using a filter to produce the measured air quality parameter value.
The method of claim 10, wherein the filter is an exponential moving average (EMA) filter.
A method for determining a composite IAQ score along a composite IAQ score range based on a plurality of measured air quality parameter values for air associated with a building space, the method comprising:

storing a composite numerical IAQ score range for each two or more composite IAQ score sub-ranges along a composite IAQ score range;

for each of the plurality of measured air quality parameter values:

storing a numerical air quality parameter value range for each of two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, wherein each of the two or more air quality parameter sub-ranges corresponds to a corresponding one of the two or more composite IAQ score sub-ranges;

identifying which of the two or more air quality parameter sub-ranges that the corresponding measured air quality parameter value falls within, resulting in an identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value;

identifying the composite IAQ score sub-range of the two or more composite IAQ score sub-ranges that corresponds to the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value, resulting in an identified one of the two or more composite IAQ score sub-ranges along the composite IAQ score range that correspond to the corresponding measured air quality parameter value;

determining an IAQ score for each of the plurality of measured air quality parameter values based at least in part on:

the numerical air quality parameter value range of the identified one of the two or more air quality parameter sub-ranges that correspond to the corresponding measured air quality parameter value;

the composite numerical IAQ score range of the identified one of the two or more IAQ score sub-ranges along the IAQ score range;

the corresponding measured air quality parameter value;

determining the composite IAQ score along the composite IAQ score range for air in the building space based at least in part on the IAQ score determined for each of the plurality of measured air quality parameter values; and

displaying the composite IAQ score on a display.
The method of claim 12, further comprising displaying on a display an IAQ category corresponding to the composite IAQ score, where the IAQ category is one or more of Good, Moderate and Unhealthy.
The method of claim 12, comprising:

controlling a building control system servicing the building space based at least in part on the composite IAQ score.
The method of claim 12, comprising:

determining when the composite IAQ score changes by at least a dead band amount for at least a predetermined time period; and

changing the IAQ category on the display when the composite IAQ score changes by at least the dead band amount for at least the predetermined time period.
The method of claim 12, wherein determining the composite IAQ score along the composite IAQ score range comprises determining a worst one of the IAQ scores for each of the plurality of measured air quality parameter values.
The method of claim 16, wherein determining the composite IAQ score along the composite IAQ score range comprises discounting the worst one of the IAQ scores for each of the plurality of measured air quality parameter values based at least in part on which of the composite numerical IAQ score ranges that the IAQ scores for each of the plurality of measured air quality parameter values falls within.
The method of claim 12, wherein the plurality of measured air quality parameter comprises two or more of CO₂, VOC, and PM.
A method for updating an IAQ score of a building space, the method comprising:

determining one or more IAQ scores for the building space based on one or more measured air quality parameter, wherein each of the one or more IAQ scores falls within one of a high, moderate or unhealthy category;

determining when one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time; and

updating a displayed IAQ category corresponding to one or more of the IAQ scores only after the one or more of the IAQ scores changes between the high, moderate or unhealthy category and remains stable for at least a predetermined time.
The method of claim 19, wherein the predetermined time is user programmable.