HK40072894B - Indoor air quality purification system for a heating, ventilation and cooling system of a building - Google Patents

Description

Indoor air quality purification system for building heating, ventilation and cooling systems

Technical Field

The present invention generally relates to an indoor air quality purification system monitor, and more specifically, to an indoor air quality monitor for exemplary use in heating, ventilation and cooling systems, for monitoring pollutants in the air returning through ducts or air processors.

Background Technology

Indoor air environments typically include suspended particulate matter such as dust, dirt, soot, and soot particles, as well as pollen, mold, bacteria, and viruses. Indoor gases are also present, released from building materials, furniture, and non-durable items. In office environments, the increased use of machinery (such as photocopying equipment) is particularly problematic because such equipment can emit volatile organic compounds (VOCs).

These particles reduce air quality, making it less pleasant and even dangerous for the occupants of the space. Modern construction techniques that improve energy efficiency, such as insulated walls, ceilings, doors, and windows, as well as encasing buildings with air intrusion barriers, have created spaces that are so airtight that buildings cannot release toxic substances.

In typical heating, ventilation, and cooling (HVAC) systems, air is drawn through filters designed to trap particulate matter. However, conventional filters are only effective against large particles at least 10 micrometers in size. While high-efficiency particulate air (HEPA) filters are more effective, they also have drawbacks, as they can become clogged quickly and require frequent replacements to avoid overloading HVAC equipment. Due to the presence of contaminants in the air and the fact that physical filters often fail to remove them, a condition known as “sick building syndrome” has been developed. Various building codes designed to mitigate this syndrome have been introduced; for example, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends a minimum of 8.4 air exchanges per 24 hours (35% turnover per hour). Although commercial and industrial facilities typically meet this minimum, their air quality may remain poor. While higher turnover rates can improve indoor air quality, they can also reduce a building's energy efficiency.

Another filtration method involves using ion exchange technology to remove pollutants from the air. Electroneutral atoms or molecules have an equal number of electrons and protons. Ionization occurs when an atom or molecule loses or gains one or more electrons. If an electron bonded to an atom or molecule absorbs enough energy from an external source, it may exceed the ionization potential and allow the electron to escape its atomic orbital. When this happens, an electron is lost, and a positively charged ion, i.e., a cation, is produced. The lost electron becomes a free electron. When a free electron subsequently collides with an atom, it can be trapped within its orbit. Gaining an electron through an atom or molecule produces a negatively charged ion, an anion.

The ionization of air (e.g., air in Earth's atmosphere) leads to the ionization of the air's constituent molecules (primarily oxygen and nitrogen). While nitrogen is more abundant than oxygen in the air, oxygen is more reactive. Therefore, oxygen has a lower ionization potential than nitrogen, allowing for the formation of oxygen cations, which are more readily formed than nitrogen cations, and oxygen has a higher electronegativity than nitrogen, allowing for the formation of oxygen anions, which are more readily formed than nitrogen anions.

Ionization is known to break down organic chemicals into their basic molecular components: water, carbon dioxide, and associated metal oxides. Therefore, ionization has the potential to purify indoor air by eliminating organic molecules and their associated odors from enclosed environments. By giving these molecules a charge, ionization also helps reduce inorganic pollutants that clump together and then fall out of the air.

Studies have shown that positive ions (cations) can harm human health in a variety of ways, such as by stimulating increased production of the neurohormone serotonin, which can lead to exhaustion, anxiety, and depression. Positive ions are frequently found in offices using visual display units (VDUs). Negative ions (anions) have a calming effect. Therefore, machines that purify indoor air should strive to introduce negative ions into the airflow.

Various commercial products have been manufactured, including machines incorporating bipolar ionization tubes. However, air ionization can also produce ozone ( _O3) , which is undesirable. Therefore, a system is needed that provides sufficient ionization levels to effectively address pollutants in the airflow while minimizing ozone production.

There is a strong desire to use ion exchange technology for air treatment, and there are indeed many suppliers of bipolar ionization tubes, which are either standalone units for specific locations or centralized units integrated into building HVAC systems. These units are used in such a way that air circulating into and recirculated within the building passes through a bipolar emitter, which typically takes the form of one or more ionization tubes. This achieves the goal of improving air quality without requiring a higher air exchange rate. Therefore, another benefit of ionizing indoor air is that it contributes to the efficiency of HVAC operations.

Indoor air quality (IAQ) detectors/monitors and controllers are installed in HVAC duct systems to help automate the ionization process therein. Detection of levels of unwanted pollutants and/or harmful gases triggers the activation of one or more ionizers, which helps reduce air pollution levels in a known manner. IAQ detectors may include various gas, particulate matter, and climate sensors that, when exceeding predetermined thresholds, trigger alarm signals sent to the controller as an early warning system. Similarly, IAQ detectors may also include sensors for detecting increasing levels of ozone produced by the ionizers, which, upon reaching predetermined levels, will signal the controller to terminate the ionization process.

Most commercial building codes require IAQ detectors to be installed in the return ducts or air handlers of HVAC systems. Current IAQ detectors are designed so that airflow in the duct passes through various sensors. Therefore, most of the various gas sensors are mounted on or flush with the outer surface of the IAQ detector housing. These sensors can include, for example, carbon monoxide (CO) sensors, carbon dioxide ( _CO2 ) sensors, total volatile organic compound (TVOC) sensors, formaldehyde ( _CH2O ) sensors, ozone ( _O3 ) sensors, particulate matter (PM) sensors, and temperature and relative humidity (RH) sensors.

It has been found that IAQ detector housings can obstruct airflow in ducts and generate unwanted airflow disturbances (e.g., eddies), leading to noise and pressure drops. Similarly, the placement of sensors on the housing results in inappropriate gas monitoring and increased maintenance of the IAQ detector. In particular, the high sensitivity requirements of some gas sensors and their positioning on or near the outer surface of the IAQ detector housing (e.g., at the front and/or sides of the housing) make the sensors more sensitive to contaminants in the airflow, which reduces sensor detection capability over time. Therefore, frequent maintenance, such as cleaning or replacement of the IAQ detector, is often required.

Therefore, there is a need in the art for an improved and more effective IAQ detector that is less susceptible to air pollutants and contaminants typically found in the ducts of HVAC systems or stand-alone equipment.

Attached Figure Description

Other advantages and features of the invention will become apparent from the detailed description of preferred embodiments with reference to the accompanying drawings, in which:

Figure 1 illustrates an exemplary air ionization purification system with a bipolar ionization tube, which is partially controlled by the indoor air quality (IAQ) monitor of the present invention, and the bipolar ionization tube is suitable for use in heating, ventilation, and cooling (HVAC) systems.

Figure 2 is a top, front, and left perspective view of the exploded IAQ monitor of Figure 1;

Figure 3 is a top, rear, and left perspective view of the exploded IAQ monitor in Figure 2;

Figure 4 is a front view of the IAQ monitor housing in Figure 2;

Figure 5 is a rear view of the IAQ monitor housing shown in Figure 3;

Figure 6 is a top view of the IAQ monitor housing shown in Figure 2;

Figure 7 is a perspective view of the top, front, and left side of the sensor mounting bridge used to mount multiple gas and climate sensors in the cavity of the IAQ monitor in Figure 1.

Figure 8 is a perspective view of the top, rear, and right side of the sensor mounting bridge used to mount multiple gas and climate sensors in the cavity of the IAQ monitor in Figure 1.

Figure 9 is a schematic diagram showing the airflow through the IAQ monitor in Figure 1; and

Figure 10 illustrates the IAQ monitor configuration for data display, data collection, and building management control.

To facilitate understanding of the invention, the same reference numerals are used where appropriate to denote the same or similar elements common to the accompanying drawings. Furthermore, unless otherwise stated, the drawings shown and discussed in the accompanying drawings are not drawn to scale but are shown for illustrative purposes only.

Detailed Implementation

Reference will now be made in detail to implementations of the invention, examples of which are shown in the accompanying drawings.

Referring to FIG1, an indoor air purification system 100 having the indoor air quality (IAQ) monitor 110 of the present invention is illustrated by way of example. The indoor air quality (IAQ) monitor 110 communicates electronically with a bipolar ionization unit 202 via a cable 222 and a controller 204. The bipolar ionization unit receives electrical energy from the cable 224 and may support other connectors, such as a two-pin aviation connector connected to the cable 223, for monitoring purposes.

An air purification system 100 is installed in a residential or commercial building's heating, ventilation, and cooling (HVAC) system according to known building and HVAC standards. The indoor air purification system 100 includes an IAQ monitor 110, which is installed in the return duct of the HVAC system to detect various undesirable gases that may be present in the air, such as carbon monoxide, carbon dioxide, formaldehyde, ozone, and climatic conditions, such as temperature and relative humidity within the HVAC system. The IAQ monitor 110 provides data and electronic signals for monitoring climatic conditions and various gases, which the air purification system 100 uses to trigger and control the bipolar ionization unit 202 to help mitigate undesirable air quality problems that can be considered to be at excessively high levels posing a health risk. The IAQ monitor 110 communicates electronically with the ionization unit 202 and the building's HVAC automation system via a wireless and/or wired electronic communication network (e.g., using the BACnet/IP protocol via the building's local area network (LAN)). Building HVAC automation systems can utilize data from IAQ monitors 110 to control certain HVAC functions to optimize HVAC efficiency. For example, by reading carbon dioxide levels, the HVAC system can automatically adjust the outside air dampers to allow minimal outside air intake and maximize efficiency. Implementing IAQ monitors in building HVAC air purification systems, the ASHRAE 62.1 IAQ procedure can be used to allow for minimal outside air intake and energy savings in the building. Those skilled in the art will understand that if outside air quality is poor, users will want to minimize the intake of outside air, not only for optimal operating efficiency but also to minimize any deterioration in indoor air quality. This is a particularly important characteristic in many geographical areas where cities have outside air quality several orders of magnitude worse than indoor air (e.g., China, India, etc.). Moreover, by continuously collecting data through the sensors of the IAQ monitor and adjusting the outside air dampers and ion intensity in real time, the impact of air quality events such as wildfires can be minimized.

Referring now to Figures 2-9, the IAQ monitor 110 is configured with an aerodynamic fin-shaped first housing portion to minimize airflow disturbance as airflow in the duct passes over or around the IAQ monitor 110. Specifically, the IAQ monitor 110 includes a housing 111 having a first housing portion 112 and a second housing portion 114, which together define an inner cavity 113 (see Figure 9). The first housing portion 112 is preferably shaped as a fin or airfoil and configured to be inserted into an internal passage of a return duct or air processor duct (not shown) through a cut or through-hole of similar size, formed in the duct system (e.g., the lower wall of the duct) to accommodate the fin-shaped first housing portion 112. The first housing portion 112 is typically inserted through the bottom wall of the duct system, and given this typical orientation, the element will be further described as “upper” or “lower.” However, this orientation is not considered limiting, because the first housing portion 110 can be oriented and mounted in the piping system along the sidewall or top of the rectangular piping system without reducing the detection capability of the sensors therein.

The first housing portion 112 includes at least one sidewall 116 defining an internal passage 115 (see FIG. 9) forming the upper portion of an inner cavity 113, and an air inlet 124 for allowing ducted airflow into the IAQ monitor 110. The second housing portion 114 is also formed by at least one sidewall 128 to define a lower portion 117 of the inner cavity 113. The upper passage 115 and the lower inner cavity 117 (see FIG. 9) together form the inner cavity 113 of the housing 111 through which air from the return duct flows, as discussed in further detail below with reference to FIG. 9. In one embodiment, the second housing portion 114 includes a support frame or sensor mounting bridge 150 for mounting a plurality of gas and climate sensors that detect the quality of the airflow passing through the IAQ monitor 110. The second housing portion 114 shown in the figure is generally rectangular in shape, although this shape is not considered limiting, as the second housing portion 114 may be square, elliptical, circular, curved, or any other shape suitable for accommodating the sensor mounting bridge 150, electronic circuitry, communication ports, and other components necessary for detecting and transmitting air quality in the pipeline system.

The shape and location of the air inlet 124 help prevent the internal sensors from fouling more quickly and/or deviating from calibration rapidly, as contaminated air does not directly enter the interior of the IAQ monitor 110. The sampling port is positioned downstream of the airflow, and the ram air effect is minimized due to the constant inlet metering fan and the calculated sampling rate. This stabilizes the sampling rate to always match the algorithm, thus improving accuracy. Furthermore, by oriented the sampling port downstream, it prevents debris that might be entrained in the airflow from substantially clogging the cross-sectional area of the sampling port. The shape of the fins or airfoil contributes to this airflow guidance process. The shape and location of the air inlet 124 are designed such that the sampling rate of the metering fan should be relatively constant, although, as is known to those skilled in the art, air processor speed and airflow can vary for many reasons and often do. A constant and repeatable sampling rate improves the accuracy, lifetime, and repeatability of data collected over long periods.

Referring to Figures 2 and 6, the first housing portion 112 includes a top 122 and an open bottom. The second housing portion 114 includes a bottom wall 129 and an open top. A first outwardly extending flange 131 surrounds the open bottom of the first housing portion 112, while a second outwardly extending flange 132 surrounds the open top of the second housing portion 114. The dimensions and dimensions of the outwardly extending flanges 131 and 132 are designed to fit together in shape after the sensor mounting bridge 150 and other electronic components are mounted in the second housing portion 114 for attachment. Preferably, a gasket 133 having a central opening 135 is inserted between the flanges 131 and 132 to form an hermetically tight seal between them. Outwardly extending flanges 132 and 133 include a plurality of spaced-apart and aligned holes 136 for receiving fasteners (not shown) to attach the IAQ monitor 110 to a piping system, wherein a first housing portion 112 is inserted into the piping system and a second housing portion 114 is mounted on the outer wall of the pipe to orient and secure the first housing portion 112 therein. When attaching the IAQ monitor 110 to the piping system, a pipe sealing gasket 134 (FIG. 2) is preferably used. The first housing portion 112 and the second housing portion 114 can be made of a variety of non-porous, moisture-proof materials, such as aluminum or stainless steel sheets, ceramic materials, polyvinyl chloride, or any other non-porous, waterproof/moisture-proof/corrosion-resistant materials.

Referring to Figures 2, 4, and 6, the first housing portion 112 is generally triangular or V-shaped, having symmetrical transverse sidewalls 116 extending between a leading edge 118 and a trailing edge or end 120 of the first housing portion 112. The leading edge 118 is configured to be positioned upstream of airflow in a duct system (e.g., a return duct or air handler in an HVAC system). In one embodiment, the top surface 122 includes markings 123 indicating the direction of airflow through the duct system. The leading edge 118 and sidewalls 116 are configured aerodynamically to minimize the structural impedance of airflow to the IAQ monitor 110 within the duct system. Preferably, the transverse sidewalls 116 are convex in shape relative to the central longitudinal axis “L” of the finned first housing portion 112 and are symmetrical in shape, although the shapes of the leading edge and sidewalls are not considered limiting, as other shapes (e.g., U-shaped leading edges and straight or curved sidewalls, etc.) can be achieved.

Referring now to Figures 3, 5, and 6, the rear or trailing edge portion 120 of the first housing portion 112 is preferably U-shaped, as best shown in Figures 1 and 6. The top 122 of the first housing portion 112 is substantially flat, as best shown in Figure 6. Those skilled in the art will understand that the U-shaped trailing edge 120 and the flat top 122 are not considered limiting, as the trailing edge 120 can be flat or substantially flat, as well as other shapes, and the top 122 can be dome-shaped, pointed, or any other curved shape that minimizes airflow disturbance within the duct system. As best shown in Figure 5, the rear or trailing edge portion 120 includes an air inlet 124 for receiving a steady flow of duct air at a controlled rate, such that multiple sensors mounted within the cavity 113 of the second housing portion 114 can sample a portion of the duct air as it passes through. The sensor and electronic circuitry are housed within the cavity 113 of the second housing portion 114 to minimize exposure to contaminants within the conduit that could adversely affect the sensor's operability, as discussed in further detail below.

Air inlet 124 is preferably formed near top cover 122 to minimize the inflow of heavier contaminants (e.g., dust, etc.) that are more likely to be present near one or more inner surfaces or walls of the duct. For example, the inner surface of the duct may be lined with a fiberglass insulation layer that readily collects dust and particles. In some applications, the insulation liner may be, for example, two inches thick. Thus, the first housing portion 112 and air inlet 124 are positioned at a height that extends sufficiently beyond (above) the liner, thereby minimizing the inflow of debris and contaminants into the interior cavity through air inlet 124. In one embodiment, the height of the first housing portion 112 is approximately 4 inches, although this height is not considered limiting. Inlet 124 may include a grille or screen to further prevent larger contaminants from entering the interior chamber 113.

Referring again to Figures 4 and 5, the second housing portion 114 includes one or more openings 121 in the sidewalls 128, the size and dimensions of which are adapted to accommodate an input or output or connector, such as an RJ-45 Ethernet connector 125 (Figures 1-3), an electrical connector 127 (Figure 2) for receiving power from an external source, a Universal Serial Bus (USB) port 126 (Figure 2), an HDMI connector 137 (Figure 2), or any other known power/communication port adapted to indicate and/or provide power/communication to and from the IAQ monitor 110. A cap 138 is provided to protect any unused connectors and ports from dust and/or moisture.

As shown in the figure, the electrical connector 127 can be connected to an external power supply 140 via wire 221. In another embodiment, the power supply 140 may be located inside the second housing portion 114.

Various inputs and outputs enable communication with other components of the HVAC system, such as the controller 204, which is exemplarily mounted on the bipolar ionization unit 202, as illustrated in FIG1. A user can optionally attach a computer monitor directly to the HDMI connector 137 to directly view the climate and gas measurements taken by the IAQ monitor 110. Although the controller 204 is exemplarily shown mounted on the ionization unit 202, this location is not considered limiting, as those skilled in the art will understand that the controller 204 can be located locally or remotely on the ionization unit 202 or the IAQ monitor 110.

Referring to Figures 7 and 8, the sensor mounting bridge 150 is schematically shown with a plurality of sensors 160 (Figure 8) mounted thereon to detect the climate and gas states of airflow in the duct system of an HVAC system. The plurality of sensors 160 exemplary include a temperature and relative humidity sensor 162, a total volatile organic compound (TVOC) sensor 163, a formaldehyde ( _CH₂O ) sensor 164, a carbon monoxide (CO) sensor 165, a carbon dioxide ( _CO₂ ) sensor, an ozone ( _O₃ ) sensor (Figure 7), and a particulate matter (PM) sensor 168 (e.g., a PM₂.5 particle sensor). The type and sensitivity of the sensors 160 mounted on the sensor mounting bridge 150 are not limiting and can vary depending on local building and external atmospheric conditions.

The sensor mounting bridge 150 is exemplarily configured as a V-shaped support and includes a plurality of raised sidewalls 152 for slots or channels 154 in which one or more sensors are mounted. The channels 154 guide airflow to the sensors to enhance their ability to detect airflow. The spacing between the sidewalls 152 forming the airflow channels 154 depends in part on the sensors mounted therein. Although the illustrated sensor mounting bridge 150 has a V-shaped structure, this shape is not considered limiting. One or more perforations or apertures 155 may be provided through the channels 154 to further distribute airflow around the sensor 160.

Preferably, a digital microprocessor 169 is also mounted in one channel 154 of the mounting bridge 150 to receive electrical signals from the sensor 160. The microprocessor 169 is programmed to determine whether a predetermined threshold associated with one or more sensors 160 has been exceeded and to send an output signal to a remote controller 204 for controlling a bipolar ion generator 202 (see FIG. 1) and/or dampers, recorders, or other airflow devices in the building's HVAC system. The microprocessor 169 can store data related to various parameters and airflow-related metrics, such as timestamps, electronic sensor signal sources, the destination of transmitted electronic signals, and any other operations related to the operation of the IAQ monitor 110.

Referring to Figures 2, 3, and 9 in conjunction with Figure 7, the electric fan 170 is mounted on the mounting bridge 150 to draw air into the inlet 124, through the inner cavity 113, and out through the air outlet 130. The electric fan 170 is preferably mounted adjacent to the air outlet 130, as shown in the slot 154F of the mounting bridge 150 in Figure 7, although this location is not considered limiting. For example, the electric fan 170 may be mounted in other areas of the inner cavity 113, such as within the upper internal passage portion 115 of the first housing portion 112, near the inlet 124 or near the open bottom between the first housing portion 112 and the second housing portion 114, and in other locations within the inner cavity 113 of the housing 110. The electric fan 170 is controlled by one or more programs executed by the microprocessor 169 to control the rotational speed of the fan blades, thereby controlling the rate of airflow into the inner cavity 113 and at the plurality of sensors 160. The rotational speed is controlled by adjusting the power supplied to the electric fan 170 from the power source 140 (Figure 1). The fan helps maintain a constant and predetermined airflow to various sensors.

Referring to Figures 2 and 3, a sensor mounting bridge 150, on which multiple sensors 160 and a microprocessor 169 are mounted, is installed within the lower inner cavity 117 of the second housing portion 114. Additionally, power and communication ports 125-127 are also preferably mounted to the second housing portion 114, although this location on the housing 111 is not considered limiting. The installation of the electronics and sensors 160 in the second housing portion 114 better facilitates access to these internal and external components from outside the piping system during maintenance/troubleshooting of the IAQ monitor 110.

Referring to Figure 9, the IAQ monitor 110 is preferably installed within the return duct or air handler of a building's HVAC system to optimally sample the air quality in one or more rooms and mitigate inappropriate sampling readings that may be caused by excessive or irregular air duct velocity, air dilution from outside air entering and mixing with the partially enclosed HVAC system, and stratification in the duct network caused by bends, expansions, contractions, etc., within the duct system. The IAQ monitor 110 is a closed housing 110, through which duct air flows in through the inlet 124, through the interior cavity 113 of the housing 111, and out through the outlet 130.

More specifically, during operation, ducted air from the HVAC system flows through the duct system, as indicated by arrow 180. The ducted airflow returning from the HVAC system flows over the leading edge 118, lateral sidewalls 116, and tail end 120 of the first housing portion 112. The aerodynamic shape of the first housing portion 112 minimizes airflow disturbance within the duct system. When the fan 170 is activated, it rotates at a predetermined rotational speed greater than the ducted airflow rate, thereby creating a low-pressure zone at inlet 124 and within the cavity 113. A portion of the ducted air 182 enters the low-pressure zone at inlet 124 and flows through the internal passage 115 of the first housing portion 112 to the cavity portion 117 in the second housing portion 114, as indicated by airflow paths 184 and 186. More specifically, the air flowing in the lower cavity portion 117 is guided over and through multiple sensors 160 via multiple channels or slots 154 formed between vertically oriented sidewalls 152, as discussed above with respect to Figures 7 and 8. Fan 170 then exhausts the air from the cavity 113 of the IAQ monitor 110 through outlet 130, as shown by airflow path 188 in FIG9. Advantageously, the sensor 160 is positioned within the cavity 113 of the housing 110, which, in contrast to the prior art where the sensor is primarily mounted on or flush with the outer surface of the monitor housing, reduces exposure to high concentrations of pollutants and contaminants within the HVAC system. These pollutants and contaminants can accumulate on the sensor after prolonged exposure and negatively impact its detection capability. Therefore, the present invention minimizes direct exposure to pollutants and contaminants in the duct airflow, thereby increasing the reliability and lifespan of the IAQ monitor and reducing the frequency of cleaning and maintenance repairs.

Another advantage is the ability to control the flow rate of air entering the IAQ monitor 110, allowing the sensors to maintain their high sensitivity levels for extended periods to detect the quality of the air passing through them.

The IAQ monitor is configured for certification by standard industry certification organizations such as RESET ^™ , which have developed healthy building certification schemes based on continuous monitoring and maintenance.

The air purification system uses data collected by the IAQ monitor 110 to automatically adjust the ion intensity level of the bipolar ionization unit 202 in response to changes in air quality, helping to maintain optimal ion saturation in the treated space for best air purification. Various monitored climate and gas conditions use a feedback loop to trigger the automatic adjustment of the bipolar ionization unit 202 when programmed thresholds are exceeded.

Figure 10 illustrates a system configuration that can be used with the IAQ monitor 110 for data display, data collection, and building management system control. As shown in box 1005, the IAQ monitor 110 can be integrated for controlling indoor HVAC functions with or without bipolar ionization (BPI), and can be integrated for HVAC systems with or without damper control for outside air intake.

As shown in box 1010, the IAQ monitor 110 can only operate in display mode. In this mode, as shown in box 1015, the user's computer monitor is directly connected to the IAQ monitor 110 via the HDMI connector 137 discussed earlier.

As shown in box 1020, the IAQ monitor 110 can be used for data collection. One method is illustrated in boxes 1025 and 1030, where comma-separated values (CSV) are saved to a USB memory thumb drive, which can be retrieved periodically by the user. Another method is illustrated in boxes 1035-1045, where sensor and node universally unique identifier (UUID) codes are obtained from the user, and a proprietary API publishes the sensor values of the IAQ monitor 110 to the user's remote server. A general algebraic modeling system (GAMS) is used to model the HVAC system for mathematical optimization.

As shown in boxes 1050-1090, the IAQ monitor 110 can be used with a building management system via a wired electronic communication network, for example, using the BACnet/IP protocol over the building's local area network. When used in this manner, the IAQ monitor 110 will use object identifiers (Oids), an identifier mechanism standardized by the International Telecommunication Union (ITU) and ISO/IEC, for naming any object, concept, or thing with a globally unique and persistent name, and a static IP advertising address assigned by the network administrator for each device connected to the network. The BACnet/IP protocol can be configured with a BACnet protocol stack and metering, available, for example, from Cimetrics and other vendors.

Data from the IAQ monitor 110 can be stored on a cloud server and made available to users. Automatic alerts can also be sent based on readings. The IAQ monitor 110 can also send routine analyses of building air quality, as well as comparisons with published IAQ standards and guidelines, and comparisons with similar buildings.

In another embodiment, the sensors can be separated to help avoid cross-interference between them.

In another alternative embodiment, NIST-certified sensors can be used, allowing the use of IAQ monitor 110 to replace traditional IAQ testing services or industrial hygiene testing, both of which are much more expensive and only provide snapshots in a timely manner.

Although exemplary descriptions of the invention have been set forth above to enable those skilled in the art to make and use the invention, such descriptions should not be construed as limiting the invention, and various modifications and variations may be made to the description without departing from the scope of the invention, as will be understood by those skilled in the art, and the scope of the invention is determined by the following claims.

Claims (17)

1. An indoor air quality (IAQ) monitor for detecting climate and gas measurements in the ductwork of a building's heating, ventilation, and cooling (HVAC) system, characterized in that the IAQ monitor comprises: A housing, the housing comprising a first housing portion defining a first internal portion and a second housing portion defining a second internal portion, the first internal portion and the second internal portion together forming an inner cavity; The first housing portion is shaped into fins configured for insertion into the HVAC ducting system of the building and has a predetermined height, a leading edge, and a trailing edge, the leading edge and the trailing edge being abutted by opposing curved sidewalls, wherein the trailing edge includes an air inlet configured to introduce a portion of air from the ducting system into the cavity, and the leading edge is configured to contact an upstream airflow within the HVAC ducting system; The second housing portion is configured to be mounted to the outer surface of the piping system and the first housing portion, thereby securing the finned first housing portion within the piping system. The housing also includes an air outlet configured to discharge ducted air from the interior of the IAQ monitor device, the air outlet being located within the second housing portion; Multiple sensors for detecting the climate and gas measurements are mounted on a support frame within a second interior portion of the second housing portion. The support frame has multiple channels, each channel for mounting one or more of the multiple sensors. The channels are configured to direct airflow from the first interior portion of the first housing portion to the vicinity of the multiple sensors and to exhaust it through the air outlet of the IAQ monitor device. An electronic circuit, comprising an electric fan and a communication port, the electric fan being configured to selectively control the flow rate of a portion of the air passing through the housing from the duct system via the air inlet and the air outlet, the communication port being configured to electronically communicate with the plurality of sensors, and the electronic circuit being configured to transmit electrical signals from the plurality of sensors to the controller of the HVAC system. 2. The IAQ monitoring device according to claim 1, wherein the curved sidewall is symmetrical in shape with respect to the central longitudinal axis of the finned shell and is convex. 3. The IAQ monitoring device according to claim 1, wherein the leading edge is V-shaped. 4. The IAQ monitoring device according to claim 1, wherein the trailing edge is U-shaped. 5. The IAQ monitoring device according to claim 1, wherein the trailing edge is flat. 6. The IAQ monitoring device according to claim 1, wherein the electric fan is installed in the inner cavity near the air outlet. 7. The IAQ monitoring device according to claim 6, wherein the electric fan operates at a predetermined rotational speed to draw in duct air through the air inlet and pass it through the plurality of sensors at a predetermined flow rate. 8. The IAQ monitoring device according to claim 7, wherein the electric fan is mounted on a support frame, and the support frame is mounted in a portion of the inner cavity within the second housing portion. 9. The IAQ monitoring device according to claim 1, wherein the plurality of sensors are mounted on a support frame, and the support frame is mounted in a portion of the inner cavity within the second housing portion. 10. The IAQ monitoring device according to claim 1, wherein the plurality of sensors include a particulate matter sensor, a carbon monoxide sensor, and a carbon dioxide sensor. 11. The IAQ monitoring device according to claim 1, wherein the plurality of sensors include a formaldehyde sensor. 12. The IAQ monitoring device according to claim 1, wherein the plurality of sensors includes a total volatile organic compound sensor. 13. The IAQ monitoring device according to claim 1, wherein the plurality of sensors include a temperature sensor and a humidity sensor. 14. The IAQ monitoring device according to claim 1, wherein the communication port includes an Ethernet connector. 15. The IAQ monitoring device according to claim 1, wherein the communication port includes a USB port. 16. The IAQ monitoring device according to claim 1, wherein the communication port includes an HDMI connector. 17. The IAQ monitoring device according to claim 1, wherein the communication port includes a power input connector for receiving power from an external source.