BR102021003423B1 - INDOOR AIR PURIFIER WITH CONTROLLED OUTDOOR AIR INLET, ULTRAVIOLET IRRADIATION OF THE HEPA FILTER AND AIR DIFFERENT WITH PLANNED STRATIFIED FLOW - Google Patents

Abstract

INTERNAL AIR PURIFIER WITH CONTROLLED ENTRY OF EXTERNAL AIR, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW. It has an external air inlet (18) that enters the device through a damper (9) mixing with the recirculated internal air for the necessary renewal, this air flow subjected to four filtering stages whose filters (4, 5, 7, 13) are properly located in the lower chamber (3, 6) and upper chamber (14). The central chamber (10) accommodates the ultraviolet lamps (12) that continuously radiate the lower surface of the HEPA H14 filter (13), in addition to also accommodating a high-performance fan (11) and the control panel (16). The purified air is distributed through a diffuser (19) which provides a stratified and planned flow.

Description

INTRODUCTION

[001] The present invention patent deals with an air purifier for indoor environments whose differential is to offer an addition of external air to the recirculation of the internal air in a controlled manner, where the recirculated air thus diluted, passes through several stages of filtration including a absolute HEPA filter that retains particles of sizes up to bacteria and viruses, a HEPA filter that is irradiated from the central chamber by an ultraviolet lamp of the UV-C spectrum, so that the air recirculated in the internal environment through a diffuser whose design provides a planned stratified flow, the load of organic and inorganic pollutants is significantly reduced.

FIELD OF THE INVENTION

[002] The invention in question is used in indoor environments for human occupation, in non-residential applications where there is a risk of contamination of indoor air (Indoor Air) by organic pollutants such as fungi, bacteria and viruses, and inorganic pollutants such as fine particulate matter and gases, especially in environments without natural ventilation and/or climatized by “split” type devices with little or no exchange of internal air with external air.

TECHNICAL CONVICTION

[003] Numerous technical references attribute great importance to the role of filtration in maintaining indoor air quality in occupied environments. IAQ is an English term that means “Indoor Air Quality”, it is internationally known and has been a subject of growing interest from public opinion and standard and regulatory bodies (ASHRAE: “Position Document on Filtration and Air Cleaning”). Diseases transmissible by particles suspended in indoor air, such as aerosols contaminated by viruses and bacteria, have affected the world as a result of epidemics and pandemics, with increasingly serious social impacts from the point of view of health, productivity and the economy as a whole. Proper Ventilation and Filtration procedures can eliminate or greatly reduce the risks of contamination of this type (ASHRAE: “ASHRAE Position Paper on Infectious Aerosols”).

[004] Recent scientific works and publications attribute significant effectiveness in improving indoor air quality (Indoor Air) due to the use of air purifiers, such as “Enhancing Indoor Air Quality - The Air Filter Advantage, Vannan Kandi Vijayan et.al ., 2015” (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4587002/ ) where the abstract contains the following information:

[005] “Air pollution has become the biggest environmental health risk in the world, associated with about 7 million deaths in 2012, according to a recent report by WHO - World Health Organization (Health Effects Institute. 2019 . State of Global Air 2019). The new data further reveal a stronger link between exposure to indoor and outdoor air pollution and cardiovascular disease, such as stroke and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary disease, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of domestic indoor pollutants (HAP) are alarming. The WHO fact sheet on PAH and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer - are attributed to exposure to household air pollution. The use of air purifiers and filters is one of the suggested strategies to improve indoor air quality.”

[006] According to ASHRAE text “62.1 - 2019: 6.1 General - The ventilation rate procedure, the IAQ procedure, the natural ventilation procedure, or a combination thereof must be used to meet the requirements of this section. In addition, the requirements for exhaust ventilation in Section 6.5 must be met, regardless of the method used to determine minimum outdoor airflow rates. Informational Note: Although the intake airflow determined using each of these approaches may differ significantly due to design criteria, any one of these approaches is a valid basis for design.”

[007] Also according to ASHRAE in its item "6.2.1.2.1 Stratified Air Distribution Systems" specifies the criterion for adopting stratified systems that, by analogy, would apply to any Purifier of Autonomous Air. The standard states: “6.2.1.2.1 - Stratified Air Distribution System. A stratified air distribution system must be designed in accordance with the following subsections, or the distribution efficiency in each zone (Ez) must be determined in accordance with Appendix C of this standard.”

[008] Appendix “C” cited in this section of the regulation provides for the use of CFD (Computational Fluid Dynamics) to determine the effective distribution of purified air.

[009] The Brazilian standard NBR-16401-3 “Air conditioning installations - Central and unitary systems Part 3:

[010] Indoor air quality” in item “5. Ventilation” as well as the internationally known standard ASHRAE “American Society of Heating, Refrigerating and AirConditioning Engineers” 62.1-2019 “Ventilation for Acceptable Indoor Air Quality” item “6.1 - General”, clearly define the obligation of certain air renewal rates for each type of indoor environment, to maintain an acceptable indoor air quality.

[011] In turn, ABNT NBR 16401-3 says: This part of ABNT NBR 16401 stipulates the minimum flow of outdoor air of acceptable quality to be supplied by the system to promote indoor air renewal and maintain the concentration of pollutants in the air at an acceptable level. The stipulated flows are dimensioned considering the expected biological, physical and chemical pollutants under normal conditions of use and occupation of the sites. The ventilation air flows stipulated in this part of ABNT NBR 16401 are independent of the capacity or type of installation.”

[012] In this context, with the above limitations, new air purifier technologies that meet the relevant standards are welcome in the segment in question. STATE OF THE TECHNIQUE

[013] The current state of the art anticipates some air purifier documents, such as PI 9804537-7 entitled "AIR FILTER, STERILIZER AND IONIZER" - in which only one element combines the functions of filtering, sterilizing and ionizing the air, providing air purification, making it more pleasant, Said air sterilizing and ionizing filter is made up of several parts: air filter, fan to effect air circulation, radiation chamber or ultraviolet light for air sterilization, ionizer donate. The format of the device can be in such a way as to have its parts in sequence, as shown in the figure, or the parts are concentric where the filter surrounds the radiation or ultraviolet light chamber.

[014] In the purifier described by the document above, in addition to not being renewed by adding external air, the ultraviolet chamber has the fictitious function of sterilizing the passing air flow. According to studies, such rapid exposure cannot eliminate biological contaminants from recirculated indoor air. According to the work by Paul J. Meechan and Christina Wilson - “Use of Ultraviolet Lights in Biological Safety Cabinets: A Contrarian View” - a minimum exposure of 30,000μJ/cm2 for at least 12.5 minutes is necessary for an effective elimination of microorganisms is achieved. From the text: “Even at the lowest acceptable irradiance in a biosafety cabinet of 40 W/cm2 (US Department of Health and Human Services et al., 2000), it takes 12.5 minutes to reach 30,000 μJ/cm2 ( 1 W = 1 J/sec), which has been listed as germicidal for spore forming organisms by a UV manufacturer (www.uvp.com/pdf/ab-115.pdf).”

[015] Patent document DE 60304015 entitled "Device for air purification" - an air purification device includes a blowing unit and a filtering unit that are easily removed and installed in a cabinet, allowing the air purification device to be air is easily cleaned. The cabinet is provided with a top panel and is open at the bottom, with air vents venting. A fan box is installed in the cabinet that can be removed in the horizontal direction. A filter box is installed under the fan box and is likewise pulled out of the cabinet in a horizontal direction.

[016] The device in the document above does not have recirculated air renewed with the outside air, in addition to the side air outlets not offering a planned stratified flow as required by applicable regulations and good technique.

OBJECTIVES OF THE INVENTION

[017] It is the objective of the present invention to propose an air purifier whose recirculation of internal air is complemented by the entrance of external air, a mandatory condition for maintaining good quality of internal air according to the applicable regulations;

[018] It is the objective of the present invention to propose an internal air purifier in which the management and control of the external air intake is based on continuous monitoring, via an air quality sensor, in order not to exceed minimum and maximum temperature limits and humidity configurable in climate-controlled indoor environments;

[019] It is the objective of the present invention to propose an air purifier equipped with UV-C lamps positioned just below the inlet surface of the HEPA filter, irradiating it directly and continuously, so that in fact there is an impact on the control of contamination by microorganisms and overcome the impossible task of air sterilization in such a short exposure time of flow passage;

[020] It is the objective of the present invention to propose an indoor air purifier whose diffuser developed through a CFD study - Computational Fluid Dynamics (Computational Fluid Dynamics Modeling) guarantees effective coverage of the area of reach of the purified air flow and also reduces the need for capture of external air that would be required by the dimensioning criterion by the simple “number of exchanges per hour”, minimizing the impact on the cooling load of air-conditioned environments, thus allowing significant energy savings;

[021] The objective of the present invention is to propose an internal air purifier with a modular construction that allows the grouping of modules to meet the demands of higher air flows or the distribution of units controlled in the “master-slave” concept in larger environments.

SUMMARY OF THE INVENTION

[022] The invention deals with a modular purifier for indoor environments (Indoor Air) comprising four filtration stages represented by a G4 pre-filter, impregnated blanket-type Activated Carbon filter, F9 fine filter and the last stage a HEPA H14 filter with retention properties even of microorganisms such as bacteria and viruses. A built-in high-efficiency fan provides the necessary pressure to reach the nominal recirculation flow, even with the filters saturated at the end of their useful life. A Butterfly Valve (damper) actuated by a stepper servo motor positioned at the back of the lower air inlet plenum, allows the controlled addition of external air through a management and control system based on continuous monitoring, via the air quality sensor. air, the level of indoor pollution and the permissible variation in temperature and humidity according to parameterization on a case-by-case basis. Therefore, the incoming air, consisting of a mixture of internal recirculated air and external renewal air, passes through the four filtering stages and is duly purified before ventilating the environment. A UV-C lamp positioned in the central chamber of the equipment continuously irradiates the lower air inlet surface of the HEPA H14 filter with the sole function of sterilizing it and reducing the load of microorganisms retained on the impact surface of this filter and still keeping the chamber sterilized central location where most of the electrical and electronic components of the sterilizer are located, in addition to being the most frequent access point for maintenance personnel. A diffuser developed through a CFD (Computational Fluid Dynamics) study provides a stratified air flow planned in order to meet the requirements of the already mentioned standards, replacing the sizing criterion by the simple “number of air changes per hour” that would require very expensive equipment. larger and less energy efficient.

DESCRIPTION OF FIGURES

[023] The invention will be described below in its embodiment, and, for a better understanding, references will be made to the attached drawings, in which they are represented: FIGURE 1: Perspective front view of the internal air purifier with inlet controlled external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 2: Rear perspective view of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 3: Exploded perspective view of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 4: Exploded perspective view of the main components of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 5: Side view of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 6: Front view of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 7: Side sectional view of the internal air purifier with controlled entrance of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 8: Anterior cutaway view of the internal air purifier with controlled entrance of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 9: Detail of the external air inlet mechanism of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 10: Detail of the application of the UV-C lamp on the inlet surface of the HEPA filter of the internal air purifier with controlled entry of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 11: Perspective view of the planned stratified flow air diffuser of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 12: Front view of the air diffuser with planned stratified flow of the internal air purifier with controlled entry of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 13: Section A-A of the full 180° air diffuser with planned stratified flow of the internal air purifier with controlled intake of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 14: A-A section of the 135° collimated stratified flow air diffuser of the internal air purifier with controlled inlet of external air, ultraviolet irradiation of the HEPA filter and air diffuser with stratified flow planned; FIGURE 15: A-A section of the 90° collimated stratified flow air diffuser of the indoor air purifier with controlled inlet of external air, ultraviolet irradiation from the HEPA filter and air diffuser with stratified flow planned; FIGURE 16: Side view of the streamlines indicating the velocity (m/s) of the air flow provided by the diffuser of the internal air purifier with controlled entrance of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 17: Three-dimensional top view of the streamlines indicating the speed (m/s) of the air flow provided by the diffuser of the internal air purifier with controlled entrance of external air, ultraviolet irradiation of the HEPA filter and air diffuser with planned stratified flow; FIGURE 18: Velocity field of the air flow streamlines provided by the internal air purifier diffuser with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 19: Schematic of the “master-slave” modular concept of the internal air purifier with controlled entry of external air, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow; FIGURE 20: Flowchart of management and control of the external air intake of the internal air purifier with controlled external air intake, ultraviolet irradiation from the HEPA filter and air diffuser with planned stratified flow.

DETAILED TECHNICAL DESCRIPTION OF THE INVENTION

[024] "INTERNAL AIR PURIFIER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW", has an external air inlet (18) that enters the device through a damper (9) mixing It is connected to recirculated internal air, an air flow submitted to four filtering stages whose filters (4, 5, 7, 13) are duly located in the lower chamber (3, 6) and upper chamber (14). The central chamber (10) accommodates the ultraviolet lamps (12) that continuously radiate the lower surface of the HEPA H14 filter (13) while preventing the exposure of people to its dangerous effects and protecting the bulb of said UV-C lamps ( 12) from dirt that could accumulate and compromise its germicidal performance, in addition to also accommodating a high-performance fan (11) and the control panel (16). The purified air is distributed through a diffuser (19) which provides a stratified and planned air flow.

[025] More particularly, the invention deals with an air purifier (1), illustrated in figures 1 to 10, for use in indoor environments, mounted in a cabinet with vertical orientation and modular concept, accessed by front doors (P) being that said modular construction cabinet (2) is capable of multiple assembly and "masterslave" type control, being divided into a lower chamber (3) that receives the G4 pre-filter (4) and the activated carbon absorbent filter for gas retention and odors (5), lower chamber (3) overlapped by a chamber (6) which receives the filter for fine particles F9 (7) and where the recirculated internal air enters through the perimeter recesses of the inlet plenum (8) plus external air that enters through a pipe (not shown) to the rear damper (9) actuated by a stepper motor. In the central chamber (10) is located the fan (11) with sufficient power to reach the nominal recirculation and external air inlet flow, in addition to the UV-C lamps (12), just below and continuously radiating the lower inlet surface of the air in the Hepa H14 filter (13) located in the upper chamber (14) sterilizing it, as well as the central chamber itself (10) where most of the electrical and electronic components of the air purifier (1) are located and where personnel maintenance service most frequently accesses. A set composed of activation keys, emergency button (15), automation sensors and control panel (16), complete the basic composition of the modular cabinet (2). The rear automatic butterfly valve called damper (9) for external air inlet operates based on continuous monitoring, via the air quality sensor (17), of the level of internal pollution and the permissible variation in temperature and humidity according to the parameterization case-by-case. -case, all commanded by the control panel (16) equipped with the power and control circuits and counting with a CPU - Central Processing Unit - and a Human Machine Interface - HMI (17). External air is admitted via a collection pipe (not shown) connected to an inlet chamber (18) equipped with a doser, that is, the external air inlet damper (9) is actuated, and is then filtered by all stages of filtering before being distributed in the internal environment. The outside air dilution rate in the recirculated air varies according to the head loss of the inlet piping, which has a limited length. This mixture of external air in the recirculation flow allows substances that cannot be filtered, such as CO2 for example, to be diluted until admissible concentrations are reached and the admission of external air is automatically interrupted. It is assumed in this case that the existing openings in the environments allow the renewal of the internal air by the positive pressure exerted by the fan (11) of the air purifier (1), positioned in the central chamber (10), which operates in a specific point of the characteristic curve , providing the constant flow and pressure necessary for operation under the expected conditions, commanded by the PID - Proportional Integral Derivative - function of a frequency inverter or its own inverter board, depending on the model adopted. The UV-C lamps (12) fixed in their own socket in the central chamber (10) are in a clean air flow position, sheltered from access by people, which at the same time avoids loss of efficiency caused by dust deposited in the bulb of the UV-C lamps (12), emission of ozone in the environment and risk to personal safety due to direct visual contact. In this proposal it is possible to reduce the contamination by microorganisms of the main filter element, that is, the HEPA H14 filter (13) and the internal components of the unit, even after maintenance operations. A diffuser (19), illustrated in figures 11 to 15, with a truncated-trapezoidal section and oblong conical holes with a specific design, around its perimeter, developed using Computational Fluid Dynamics (CFD), with an upper closing cap in steel, promotes a stratified and planned air flow (consecutive drawings to Figure 11). One of the parameters used in the development of the invention is the theoretical airflow pattern defined in the CFD computational study. This criterion provided for in the Applicable Standards (ASHRAE 6.2.1.2.1, 6.2.1.2.2 and Appendix C) allows using a much smaller volume of external air for ventilation with equivalent or even better results in terms of decontamination of the internal air when compared to the sizing criterion by the simple “number of air changes per hour”. It also allows, and for this reason, a significant saving of air conditioning energy. The diffuser (19) makes it possible to increase the scope of the purified air flow and also collide the air outlet at angles of 180°, 135° and 90°, further optimizing the distribution of air in the areas of interest, that is, the breathing zone of the occupants. A power and control panel (16), installed inside the central chamber door (10), receives information from sensors distributed by the purifier, being commanded by a CPU and a Touch Screen HMI (17), in addition to containing all the electrical and electronic components necessary for the operation, allowing the construction of air purifiers (1) with up to four modules (2) physically integrated or distributed in a “master-slave” concept, commanded by a single panel (16).

[026] As shown in figure 20, the process of managing and controlling the entry of external air into the air purifier (1) begins in a first step (E1) in which the air quality reading sensor (17) makes the readings of the concentration value of each monitored pollutant (CPV); humidity in % (UMv); temperature in degrees Celsius (TPV); humidity range (UMF); temperature range (TPF); damper opening (DA); Damper lock (DF); climate control enable (AC), for a second stage (E2) to enter a loop. In a third step (E3) it verifies if the CPV is outside the maximum limits of permissible concentration of pollutants using the IAQ-i algorithm.

[027] If not (N) in a fourth step (E4) it returns/keeps the fan at minimum speed - standby, to in a fifth step (E5) close and/or keep the damper in this position. If positive (S) in the third stage (E3), the process proceeds to a sixth stage (E6) where the fan speed is increased with the action of the frequency inverter. [027] In a seventh step (E7) the Damper opens, in order to in the eighth step (E8) check if the air conditioning is enabled. If not (N) it returns to the second stage (E2). [028] If so (S), in the ninth step (E9), check if the TPV is within the TPF range, if so (S) in a tenth step (E10) check if the UMv is within the UMF range and, if so, it returns to the second stage (E2). If not (N) in the ninth or tenth stage (E9 or E10) it proceeds respectively to an eleventh or twelfth stage (E11 or E12) where the damper is closed and a failure warning appears on the HMI screen and in the reports: “Insufficient air conditioning capacity” (A).

Claims (7)

1) “INTERNAL AIR PURIFIER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW” mounted in a vertically oriented modular cabinet equipped with a fan (11), accessed through front doors (P) , with filtration stages in the lower chamber (3) which receives the G4 pre-filter (4) and the activated carbon filter (5); the chamber (6) that receives the fine particle filter (7); the central chamber (10) where the UV-C lamps (12) are accommodated and the upper chamber (14) the HEPA H14 filter (13) which acts based on the continuous monitoring of the level of internal pollution; the UV-C lamps (12) are positioned just below and continuously irradiating the lower air inlet surface in the Hepa H14 filter (13) located in the upper chamber (14); UV-C lamps sterilize the central chamber (10); characterized by a modular construction cabinet (2) that on its back face has an automatic valve, damper (9) that captures external air to add to the recirculated air, generating an air flow via an air quality sensor (17), and in the permissible variation of temperature and humidity according to parameterization; a truncated-trapezoidal diffuser (19) with oblong conical holes around its perimeter, developed using computational fluid dynamics (CFD) with a steel upper closing cap, which promotes a planned stratified air flow. 2) "INTERNAL AIR PURIFIER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW" according to claim 1 characterized by having an actuated damper (9) incorporated into the air inlet plenum (8) allows the controlled admission of external air to the recirculation flow observing the limits of maximum allowed variation of the temperature and humidity of the internal air. 3) "INTERNAL AIR PURIFIER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW" according to claim 2 characterized by the mixing of external air based on continuous monitoring, via sensor of air quality (17), the level of internal pollution and the permissible variation of temperature and humidity according to parameterization. 4) “INTERNAL AIR PURIFIER WITH CONTROLLED ENTRY OF EXTERNAL AIR, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW” according to claim 1 characterized by a diffuser (19) of truncated-trapezoidal section and oblong conical holes with specific dimensions, throughout its perimeter promoting a stratified and planned air flow. 5) "INTERNAL AIR PURIFIER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW" according to claim 1 and 4, characterized by the diffuser (19) with construction in full 180° versions and collimated at 135° and 90°. 6) "INTERNAL AIR PURIFYER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW" according to claim 1 characterized by the modular construction cabinet (2) allowing the grouping of modules for service of higher air flow demands or the distribution of commanded units in the “master-slave” concept. 7) "INTERNAL AIR PURIFIER WITH CONTROLLED EXTERNAL AIR ENTRY, HEPA FILTER ULTRAVIOLET IRRADIATION AND AIR DIFFUSER WITH PLANNED STRATIFIED FLOW" according to claim 1 characterized by the management and control of the external air intake being carried out by monitoring in real-time concentration of pollutants through an air quality sensor (17) that indicates concentrations of pollutants, CO2, PM10, PM 2.5, TVOC, in addition to temperature and humidity; measurement of pollutant concentration, in addition to being translated into an air quality index via the proprietary IAQ-i algorithm, defining and controlling the opening and closing of the external air inlet damper (9) and the purifier air flow through the action of the frequency inverter in the rotation of the fan (11).

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