Integrated system for ensuring a predetermined optimal quality of confined air and for preventing risks arising from the presence of hazardous gases at the minimum energy cost, and related operation process

Abstract

The present invention describes an integrated system for ensuring a predetermined optimum quality of confined air and for preventing risks deriving from the presence of hazardous gases at the minimum energy cost, consisting of: - an electromechanical device for the air and heat exchange, comprising: ∘ an internal dispenser / expeller; ∘ at least a graphene membrane configured so as to increase the exchange surface ∘ at least a fan; ∘ at least two filters, at least one thereof capable of cleaning the air from physical particles of pollutants and at least one capable of cleaning the air from microbiological contaminants; ∘ an external expeller / extractor; ∘ flow separators; ∘ an external piping consisting of a heat-insulating tube with variable thickness based on the thermal areas and an internal piping consisting of a heat-conducting tube acting as a flow separator; ∘ temperature sensors positioned at the inlet and outlet of the air and suitable for detecting the temperatures of the air entering and leaving the electromechanical device; ∘ a communication antenna; - a control unit monitoring the air quality inside a confined environment, comprising: ∘ a high efficiency universal switching power supply; ∘ a microcontroller; ∘ a communication antenna; ∘ an air recirculation fan; ∘ a digital switch to provide power to the sensors; ∘ at least one digital sensor to detect at least one value relating to at least an air quality parameter and / or an explosive gas; ∘ at least one digital sensor to detect at least one value relating to at least a pollutant and / or an explosive gas and for asynchronous communication with said electromechanical device; ∘ at least a digital sensor for detecting at least one value relating to at least a pollutant and / or an explosive gas and for synchronous communication with said electromechanical device ∘ a timer, Said system is characterized in that the control unit is configured to process the data coming from the sensors in order to detect the air quality per unit of time, to calculate the frequency of the detections of the values exceeding a predetermined threshold value and to regulate the speed of the fans of said electromechanical device, and, moreover, to process the data coming from said temperature sensors and to calculate the temperature difference between the exhausted indoor air coming out and the external air coming in and to regulate the countercurrent air flows so as to recover the thermal energy by means of said graphene membrane. The invention also describes the system operation process.

Description

Field of the invention

[0001] The present invention places in the field of the environmental technologies belonging to the complex management of the air quality in confined environment.

[0002] More in detail, the invention consists of an articulated electronical-mechanical system comprising of several sensors capable of monitoring, with extreme precision, the air quality in a confined environment and to modify the composition thereof to make it safe and optimum, by importing air from outside, after suitable filtering and at the minimum energy cost. This invention is aimed at protecting the health of that increasingly part of the population who lives and works in closed spaces (ex. school, hospitals, offices, shopping centres, remote working, residential buildings and especially bedrooms, etc.).State of art

[0003] The air quality in the closed environments is often far from being optimum, with significant consequences on human health. Respiration in such environments leads to a reduction in oxygen content and an increase in carbon dioxide, causing respiratory fatigue.

[0004] Moreover, a series of pollutants coming from internal sources, like fine dust, moulds, PM2.5, PM10 radon, various gases and volatile organic compounds, can irritate the respiratory tract in the long term and increase the risk of chronic respiratory diseases, thereamong asthma and obstructive bronchopneumonia disease (BPCO).

[0005] Some pollutants and the particulate can penetrate the circulatory system and increase the risk of cardiovascular diseases including heart disease and stroke, or can influence brain function, causing the onset of neurological diseases such as dementia, Alzheimer and Parkinson.

[0006] Poor air quality can also compromise the proper functioning of the immune system; it is also necessary to consider that some substances present in the air are carcinogenic substances and, consequently, can be correlated with the onset of tumours. Therefore, it is essential to ensure a good quality of the indoor air to preserve health and well-being of people.

[0007] The deterioration of the air quality inside homes can also derive from the external pollution; the simple act of opening a window to ventilate a room can cause the entry of potentially harmful polluting substances. In many urban areas, outdoor air is heavily polluted, which could compromise the efforts to improve the air quality in the internal environments through ventilation. In such cases alternative or complementary solutions may be necessary to ensure a healthy internal environment, such as the use of high-efficiency air filters or incoming air purification systems.

[0008] Moreover, it is important to consider that many pollutants can be generated also inside buildings from sources such as chemical products, inadequate building materials used, household appliances, heating systems and human activities that require the use of chemical products.

[0009] Therefore, an integrated management of both indoor and outdoor air quality is required to face effectively this problem.

[0010] Air quality monitoring is crucial in various contexts, including private residences, and public places such as hospitals, offices, schools, hotels and other, basing on the parameters, established by law for each European Country, which define the values of optimal indoor quality air.

[0011] Among these parameters there are humidity and temperature; ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers), EPA (Environmental Protection Agency) and WHO (World Health Organization), recommend a relative humidity between 30% and 50% and temperature comprised between 20°C and 24°C (68°F and 75°F). In particular, it was noted that the relative humidity below 60% limits the growth of moulds in the environment and even lower levels of humidity seem to be able to help in preventing the proliferation of microorganisms responsible for allergic reactions such as mites.

[0012] It was studied that the temperature between 20 and 24°C limits the bacterial proliferation, moreover, the temperature kept around 20°C reduces the use of energy and allows to save cooling and heating costs.

[0013] As to CO 2 the World Health Organization (WHO) often recommends a maximum of 1,000 ppm for CO 2 in order to guarantee a good comfort and a good quality of the internal air. Whereas ASHRAE recommends a concentration of CO 2 lower than 700 parts per million (ppm) in internal environments; the main sources of CO 2 in the closed environments are human respiration and insufficient ventilation; CO 2 can increase even following an increased respiratory rate or even for some activities linked to food cooking or the use of combustion devices.

[0014] In relation to the PM (Particulate Matter), WHO standards also suggest limits of 25 µg / m 3< per PM2.5 (daily average) and 50 µg / m 3< per PM10 (daily average). The PM particles are so small that they can be breathed in and can reach the deepest parts of the respiratory system, including bronchioles and alveoli. The prolonged exposure to PM can cause irritation in the airways, increase the incidence of chronic respiratory diseases such as asthma and bronchitis, and aggravate pre-existing conditions. The PM can enter the blood flow through the lungs and influence the cardiovascular system by increasing the risk of heart diseases, stroke, and other problems of the circulatory system as well as the prolonged exposure can increase the risk of developing lung tumours and other forms of cancer.

[0015] Another aspect to be considered is the Volatile Organic Compounds (VOC) which represent a class of chemical substances which can evaporate easily in air at room temperature. These compounds can be released in air from paints, glues, sealants, furniture, floors, coverings, many detergents, disinfectants, cleaning products, perfumes, deodorants, inks, cosmetics and some electronic equipment during use. The exposure at high COV levels can cause irritation of the respiratory tract and neurological problems such as headache and dizziness; some COVs, such as benzene and formaldehyde, are classified as carcinogenic and they can increase the risk of developing tumours.

[0016] Among the pollutants there is also the carbon monoxide (CO), for which the European directive about the quality of ambient air establishes maximum limits for the CO concentration in air: 10 mg / m 3< (milligrams per cubic meter) for a period of 8 hours as daily average and 35 mg / m 3< in hourly average; CO mainly comes from the incomplete combustion of carbon during the use of fuels such as natural gas, coal, wood and gasoline. Prolonged exposure to CO or high levels can cause permanent damages to heart, brain and other organs.

[0017] Even oxygen (O 2 ) is an essential component of the air quality and plays a fundamental role in maintaining human life. OSHA does not indicate a specific lower limit for the concentration of oxygen in air, but indicates that the normal percentage in air has to be 20.9%; on the contrary the National Institute for Occupational Safety and Health (NIOSH) suggests that the oxygen concentration should be kept above 19.5% in percentage volumes.

[0018] The human activity, but also the use of apparatuses or systems involving the combustion (such as gas stoves, heaters, etc.), may influence the oxygen levels. In crowded environments or during intense physical activities, the oxygen concentration can decrease due to the consumption by the present people and then its monitoring becomes crucial; infact, too low oxygen levels can reduce the energy available for the body, leading to a feeling of tiredness and potentially hypothermia.

[0019] Indoor ozone (O 3 ) can accumulate in closed environments, especially in presence of electronic equipment, electrical devices or processes which can generate ozone as byproduct. For example, some printers, photocopiers and electronic equipment could contribute to the presence of ozone. The exposure to high levels of ozone can cause irritation of the respiratory tract, causing cough, sore throat and breathing difficulty. OSHA established an exposure limit of 0.1 ppm (parts per million) for a period of 8 hours for the workers whereas ACGIH established a TLV-TWA (Threshold Limit Value -Time Weighted Average) of 0.05 ppm for ozone in the indoor environments.

[0020] Among the environmental pollutants there is even formaldehyde (CH 2 O) which is a gas classified as a volatile organic compound (VOC) and it is emitted by a variety of common sources in the internal environments, such as furniture, building materials, paints, glues, carpets, fabrics and cleaning products; the prolonged exposure to formaldehyde can cause irritation of the respiratory tract, headache, cough and, in some cases, it can contribute to the development of chronic respiratory conditions and, moreover, the International Agency for Research on Cancer (IARC) classifies formaldehyde as carcinogenic substance for human beings. According to OSHA in the working field, formaldehyde has not to exceed 0.75 parts per million (ppm) in air for a weighted average during 8 hours, whereas the National Institute for Occupational Safety and Health (NIOSH) sets an exposure limit of 0.016 ppm up to 10 hours. Among the gases there is also methane which is highly flammable and can form explosive mixtures in air when present in adeguate concentrations. In environments where natural gas or methane leaks may occur (such as kitchens, gas systems, etc.), methane monitoring is essential to prevent the risk of explosion.

[0021] Then, it is important to adopt preventive measures to reduce the negative impact on human health and life, resulting from exposure to high concentrations of CO 2 , particulate, ozone, formaldehyde and other pollutants, as well as explosive gases or powders.

[0022] Currently, air quality monitoring and control are often implemented by using separate systems for the detection of specific pollutants, such as fine dust, CO 2 , and VOC (Volatile Organic Compounds). However, these separate systems can be expensive, complex to be installed and to be managed, and they do not offer a complete and integrated view of air quality.

[0023] Regular ventilation is certainly one of the recommended solutions to improve air quality.

[0024] Opening windows, which is usually the common practice to renew the internal air, often involves a significant waste of energy. For example, in winter, by opening windows a large part of the thermal energy produced by the heating system is dispersed in the atmosphere, by generating unnecessary environmental pollution. The same is valid for summer, when the cooling of the internal air is compromised by opening windows, allowing the external heat to infiltrate causing an obvious waste of energy; besides, opening windows does not always guarantee the entry of air of good quality from the point of view of the concentration of the external pollutants.

[0025] The energy cost associated to ventilation can be significant, especially in environments where air heating or cooling requires the use of high amounts of energy. This can be particularly relevant in extreme climates where maintaining comfortable temperature is essential for people's well-being; for this reason, several solutions have been devised that can help in reducing energy consumption associated with ventilation, such as the use of heat recovery system to pre-heat or pre-cool incoming air using exhausted air, although such systems, however, involve energy consumption.

[0026] In the state of art, several patent documents illustrating controlled mechanical ventilation (CMV) devices with heat recovery are known.

[0027] Patent documents are also known, illustrating the new application of graphene and other advanced technologies to develop more effective, durable and compact ventilation, heat exchange and air purification systems, thus contributing to improve safety, comfort and health in the internal environments.

[0028] The document CN207688347U illustrates a countercurrent flow heat exchanger using a membrane made of graphene for the heat exchange. Suitable filters trap the whole micro-duct present in the air. Subsequently, other filters purify the air from possible microbes and bacteria. This clean air crosses externally the graphene piping from outside to the inside. The unhealthy indoor air flows in the internal graphene piping, from the inside to the outside. The speed of the two countercurrent flows is the lowest possible to guarantee the planned healthiness of the indoor air in order to maximize the heat exchange between the two currents, minimizing the energy costs and the environmental impact. The exchange speed, instead, is the maximum possible in case of presence of gases or explosive powders in the indoor air. The so implemented system does not compromise the functionality of the graphene sheet since it is in contact with air cleaned by filters of both flows. In this way the graphene membrane remains perfectly effective for a very long period of time without requiring any maintenance. The filters have to be replaced when their effectiveness reduces and instead of producing advantages they transform into a cost and an environmental impact whose value can be and must be minimized.

[0029] The document CN1 07355927 A describes an indoor apparatus for the air conditioning having several advantages even if it uses a traditional air conditioning structure; the fan and the exhaust fan are integrated, they occupy a small space and allow to save energy; the heat exchanger, provided with a graphene layer, is used to keep the internal air under the effect of the conditioned air cooling or heating; the apparatus allows to improve the heat exchange and the purification effect, with considerable advantages in operating costs which compensate the cost of the graphene used for the purification layer.

[0030] The document CN110779189A is an air purification system consisting of an air conditioner and a graphene nanofiber membrane total heat exchanger which allows to enter air from outside in the confined environment at a temperature very similar to the temperature of the confined environment itself, in this way by reducing the energy consumption.

[0031] The document CN112539537A illustrates a device for the thermal energy recovery applicable to a highly effective heat exchange ventilation system which integrates a filter and a heat accumulation plate thus allowing the heat exchange during air filtering; the path of fresh air to be entered and the one of the exhaust air to be extracted from a confined environment are separated and they do not interfere with each other.

[0032] The document CN216308060U relates to an air conditioner in which a nano material, for example graphene, coating the fins of the ventilation devices, is applied; moreover said fins are wider so as to increase the heat exchange area, to insulate effectively the compressor heat, to reduce considerably the impact on the condensation heat exchanger, to improve considerably the heat exchange effectiveness, to improve the energy effectiveness of the whole machine.

[0033] The mentioned patent documents relating to the state of art relatively to the problem of monitoring the air quality provide an important overview of the existing technologies. However, it is crucial not to overlook their disadvantages, which can impact deeply on the overall effectiveness of the environmental surveillance systems.

[0034] One of the main obstacles is represented by the high costs associated to the installation and management of the several separate monitoring systems. This involves a considerable financial investment by the organizations, which have to face the expenses for purchasing the dedicated hardware, the implementation of specific software and the formation of qualified personnel for the maintenance and the operation of the devices.

[0035] Additionally, the complexity in integrating the data coming from several monitoring sources, the lack of standardization and diverse data formats can delay the analysis and response to the environmental problems.

[0036] At last, the lack of a complete and integrated solution for the dynamic and optimized control of the air quality represents an additional disadvantage. Notwithstanding the existence of several monitoring systems, a unified approach to react in real time to the air quality variations could be absent. This could require the implementation of additional actions or systems to mitigate the negative effects on the environment. Therefore, the state of art highlights the need for improving the efficacy and effectiveness of the environmental management systems.

[0037] The invention solves these problems by providing an effective system which preserves the quality of the indoor air without compromising the energy efficiency. This directly contributes to human well-being, by guaranteeing an environment healthy and comfortable for everyone.Summary of the invention

[0038] The invention relates to an articulated system for detecting, through suitable specific sensors, two categories of pollutants: the ones at low risk and the ones at high risk.

[0039] The analysis of the air quality is performed through a complex integrated system of sensors for monitoring and controlling the air quality coming from outside and indoor, with particular attention to the reduction of energy consumption for the air exchange through a innovative countercurrent air flow heat recovery system.

[0040] The systems consists of two main components: an electronic control unit for the detailed monitoring of the indoor air quality and an electromechanical device for the air exchange with heat recovery.

[0041] The system consists of two distinct units communicating to each other through conveyed waves or wireless communications. A unit is dedicated to the detailed monitoring of the air components by using a countless series of sensors capable of monitoring all air components of interest, whereas the other one manages the air exchange between the internal and external environments, by preserving at the same time the maximum energy efficiency. In short, the system aims at obtaining safe and clean air at minimum cost.

[0042] The control unit processes the data received from a series of advanced sensors, including those for measuring CO 2 , VOC, humidity and temperature, explosive substances, in order to monitor constantly the internal air quality.

[0043] The electromechanical device for exchanging air exploits the heat recovery to capture the heat from the exhausted air coming from the internal environments and to use it to pre-heat or pre-cool the air coming from outside. This allows to reduce significantly the energy consumption associated to heating or cooling of the environments, by improving at the same time the internal air quality.

[0044] The proposed system is an integrated system for monitoring and controlling the air quality, which uses a combination of advanced sensors and filtering technologies for ensuring a healthy and comfortable internal environment.

[0045] The system detects and analyses in real time the levels of several pollutants present in the internal air and adjusts automatically ventilation and the filtering system to keep the air quality within the wished parameters.

[0046] The invention also described the system operation process.Description of figures

[0047] The invention will be better comprised by the following detailed description with reference to a preferred, but not exclusive, embodiment of the integrated system according to the present invention, shown by way of example and not for limitative purposes, and with particular reference to the enclosed figures, wherein: figure 1 illustrates an overall schematic view of the system and of the interaction between the related devices; figure 2 illustrates a flow chart relating to the operation of the electromechanical device in presence of general polluting gas; figure 3 illustrates a flow chart relating to the operation of the electromechanical device in presence of explosive gases. Legend

[0048] 1electromechanical device with heat recovery for exchanging air and heat (exchanger) 1.1 internal dispenser / expeller shaped like a sphere fraction; 1.1.1 through holes for extracting indoor air; 1.1.2 through hole for entering depurated air; 1.2 variable speed fan; 1.3 graphene membrane piping; 1.4 spacers; 1.5 PM 2.5 and PM 10 filters; 1.6 variable speed fan; 1.7 external expeller / extractor shaped like a sphere fraction; 1.7.1 through holes to expel air; 1.7.2 through holes to suction air from outside; 1.8 flow separator; 1.9 flow separator; 1.10 external piping; 1.11 internal piping - flow separator; 1.12 spacer; 1.13 temperature sensor; 1.14 temperature sensor; 2control unit 2.1 high-efficiency universal switching power supply; 2.2 microcontroller; 2.3 communication antennas; 2.4 air recirculation fan; 2.5 loudspeaker for reproducing sounds; 2.6 signalling coloured LEDs; 2.7 digital switch controlled by the microcontroller suitable to provide power to the sensors; 2.8 analog sensors with analog multiplexer controlled by the microcontroller 2.9 digital sensors with asynchronous communication with multiplexer controlled by the microcontroller; 2.10 digital sensors with synchronous communication with multiplexer controlled by the microcontroller; 2.11 timer Detailed description of the invention

[0049] The present invention described an integrated system 100 for ensuring a predetermined optimal quality of confined air and for preventing the risks deriving from the presence of hazardous gases at the minimum energy cost, consisting of: an electromechanical device 1 for exchanging air and heat, comprising: ∘ an internal dispenser / expeller 1.1; ∘ at least a graphene membrane 1.3 configured so as to increase the exchange surface; ∘ at least a fan 1.2, 1.6; ∘ at least two filters, at least one thereof capable of cleaning the air from the physical particles of pollutants and at least one cleaning the air from contaminants of microbiological type; ∘ an external expeller / extractor 1.7; ∘ flow separators 1.8, 1.9; ∘ an external piping 1.10 consisting of a heat-insulating tube with variable thickness based on the thermal areas and an internal piping 1.11 consisting of a heat-conducting tube acting as flow separator; ∘ temperature sensors 1.13, 1.14 positioned at the air inlet and outlet and suitable to detect the temperatures of the air entering and leaving the electromechanical device 1; ∘ a communication antenna; a control unit 2 monitoring the air quality inside a confined environment, comprising: ∘ a high-efficiency universal switching power supply 2.1; ∘ a microcontroller 2.2; ∘ a communication antenna 2.3; ∘ an air recirculation fan 2.4; ∘ a digital switch to provide power to the sensors 2.7; ∘ at least one analog sensor 2.8 to detect at least one value relating to at least an air quality parameter and / or an explosive gas; ∘ at least one digital sensor 2.9 to detect at least a value relating to at least a pollutant and / or an explosive gas and for asynchronous communication with said electromechanical device 1; ∘ at least one digital sensor 2.10, to detect at least one value relating to at least a pollutant and / or an explosive gas and for synchronous communication with said electromechanical device 1; o a timer 2.11.

[0050] The control unit 2 is configured to process the data coming from said sensors 2.8, 2.9. and 2.10 per unit of time, to calculate the frequency of detections of values exceeding a predetermined threshold value and to regulate the speed of the fans 1.2, 1.6 of said electromechanical device 1 and to process the data coming from said temperature sensors 1.13, 1.14 and to calculate the temperature difference between the exhausted indoor air coming out and the purified external air coming in and to regulate the countercurrent air flows. The electromechanical device 1 is configured to expel the air present inside a confined environment at variable speeds and to enter air from outside at variable speeds, by cleaning it by at least two filters 1.5.1; 1.5.2, and in that it is configured to recover the thermal energy by regulating countercurrent air flows by means of said graphene membrane 1.3 based on the commands received from said electronic control unit 2.

[0051] The integrated system according to the present invention aims at achieving the following two objectives: guaranteeing an optimum quality of indoor air, without pollutants both at low risk and at high risk; limiting drastically the heat energy consumption relating to the air exchange.

[0052] The integrated system according to the present invention, illustrated in a preferred embodiment in figure 1, consists of a complex electronic control unit 2, monitoring the air quality inside a confined environment, and of an electromechanical device 1 with thermal recovery for the air and heat exchange, or an exchanger, which expels the exhausted and polluted air present inside an environment and enters air from outside, previously cleaned by using suitable filters, and it recovers as much thermal energy as possible through countercurrent air flows separated by a graphene surface.

[0053] More in detail, figure 1 illustrates the structure and operation of the system with countercurrent air flows.

[0054] The electronic control unit 2 is configured to regulate dynamically the speed of the fans based on the values of the parameters detected by said sensors 2.8, 2.9. and 2.10 in relation to the presence of at least a pollutant and / or an explosive gas, based on the frequency of the detections exceeding a predetermined threshold value and to command one or more air exchange cycles in the time unit in order to ensure a predetermined optimal quality of confined air.

[0055] The main operation of the system, by means of said electromechanical device 1 for the air exchange with heat recovery, consists in expelling the indoor air at variable speeds depending on the command received from the electronic control unit 2, or alternatively at very high speed in case of explosion risk and at low speed in other cases. The outgoing flow is that of polluted air with its own thermal content; the incoming flow is that which comes from outside after purification and disinfection. The indoor air to be expelled by means of the electromechanical device 1 follows a specific path illustrated in figure 1.

[0056] The indoor air is oriented by means of through holes 1.1.1 of an internal dispenser / expeller shaped like a sphere fraction 1.1, through a first fan 1.2, at variable and electronically controlled speed, which adjusts the entry and exit of air and conveys it along the outside of a membrane graphene piping 1.3 to be then expelled through the through holes 1.7.1 of the component 1.7; the membrane graphene piping 1.3 has a particular shape so as to have a big surface in the minimum space.

[0057] The indoor air flow hits a thermal sensor, 1.14, which measures the temperature and transmits the value to the control unit 2.

[0058] The two flows, separated by the membrane graphene piping 1.3, with micrometric thickness (so that it has a very long duration and a great thermal transmittance), while flowing in countercurrent, exchange heat with the purpose of making the inlet air temperature to be equal to the expelled one.

[0059] Graphene, apart from an optimum mechanical resistance, has an extraordinary thermal conductivity, higher than many other known materials; this property makes it effective in transferring heat and makes it to be suitable in an effective heat exchange. In order to improve the thermal efficiency the membrane graphene piping 1.3 is provided with a big exchange surface since it is shaped with star section (with the purpose of having in the minimum volume of the exchanger the maximum exchange surface to maximize the thermal efficiency) and with the expulsion surface equal to the adduction one.

[0060] Still in order to optimize performance, the electromechanical device 1 uses the useful minimum speed commanded by the control unit.

[0061] With such geometry and use, the heat performance is variable; very high when the exchange speed is very low and modest when, in case of risk of explosion, the speed is very high. In this case automatically, the control unit prioritizes safety of people and things rather than heat recovery.

[0062] The electromechanical device 1 is devised to comply with the request for air exchange at the time and modes determined by the electronic control unit.

[0063] The diameter of the electromechanical device 1 can have different sizes depending upon the volume to be controlled; for example, in case of a bedroom of 20 mq, height 3 metres and occupied by thee people, a diameter of only 10 cm is sufficient.

[0064] The external air is extracted by a second fan 1.6 at variable speed, having greater power and controlled electronically, which regulates the air incoming and outgoing, from outside towards inside; crossing through holes 1.7.2 of the component 1.7 the air flows inside the graphene membrane piping 1.3, after being purified, through a filter 1.5 dedicated to capture all polluting microparticles, in particular, but not only, PM 2.5 and PM 10.

[0065] The greater power of the fan 1.6 is justified since the air meets a certain resistance, since it has to cross different filters to intercept micropowders, bacteria, viruses and other pollutants.

[0066] In particular the air crosses two filters, at least one thereof cleans the air from the physical particles of pollutants and at least one cleans the air from contaminants of microbiological type.

[0067] The electromechanical device 1 for the exchange of air and heat is provided with an external piping 1.10 consisting of a heat-insulating tube with very low thickness so as not to disperse heat outside the system, and an internal piping 1.11, acting as flow separator, consisting of a heat-conducting tube, and a spacer 1.12.

[0068] The electromechanical device 1 for the exchange of air and heat is further provided with an integrated electronic circuit which manages communication at frequencies of 2.4GHz and 5GHz and with temperature sensors 1.13, 1.14, positioned at the air inlet and outlet in order to allow to evaluate the thermal conditions and to optimize the air exchange speeds to maximize the overall efficiency of the system.

[0069] In the countercurrent air flow the difference of temperature between incoming flow and outgoing flow remains constant; in case the temperature of the indoor air is very close to the temperature of the external air, the thermal exchange is close to zero; on the contrary, in case the external temperature is much lower than the internal one the exchange efficiency becomes important since the amount of energy that would be lost would be very significant.

[0070] Figure 1 highlights that the air flows never cross; speed and operation time of fans 1.2, 1.6, respectively responsible to manage the outgoing and incoming flow, are managed by the control unit 2 depending on the analyses coming from the sensors.

[0071] Figure 1 illustrates also a schematic view of the operation of the electronic control unit 2.

[0072] The components of the control unit are detailed hereinafter: a high-efficiency universal switching power supply 2.1, projected to be compatible with different International electrical networks; a low energy consumption microcontroller 2.2 capable of managing a series of mathematical calculations and complex algorithms and provided with ISM wireless connectivity features, then with the possibility of interacting with the cloud on Internet or other connected devices, by allowing the remote control and the information exchange in real time; an air recirculation fan 2.4 activated by the microcontroller is required to move the air inside the control unit box so as to take the indoor air of the room; a loudspeaker 2.5 is used to reproduce sounds when it is necessary to warn occupants of poor air quality levels; the sound volume can be regulated and deactivated by the microcontroller. coloured signalling LED 2.6 are arranged to warn occupants about the air quality levels; through a variety of colours and light effects, these LEDs show different pollution levels and the operating status of the system, providing an immediate visual feedback.

[0073] The digital switch 2.7 provides power to the air quality sensors, directly controlled by the microcontroller so as to preserve sensor longevity.

[0074] The control unit is provided with communication antennas 2.3 for ISM bands, integrated into the box or screwed externally in order to have greater capacity.

[0075] The aim of ensuring a optimum indoor air quality, without both low risk and high risk pollutants, is achieved then by means of several sensors with which the control unit 2 is provided, which monitor constantly the quality of the indoor air by aligning it to optimal values.

[0076] The control unit, through suitable specific internal sensors, examines the indoor air quality and, with particular attention to the energy consumption reduction, through communication with the electromechanical device 1 for the exchange of air and heat, commands the indoor air exchange.

[0077] The analog sensors 2.8 are provided with a multiplexer, controlled by the microcontroller, which can select in sequence the desidered sensor and convert the analog signal in digital form for processing.

[0078] The digital sensors 2.9, 2.10, respectively with asynchronous and synchronous communication, are also provided with a multiplexer, managed by the microcontroller, which can select in sequence the desidered sensor for data acquisition.

[0079] The electronic control unit 2 is provided internally with said sensors for measuring O 2 , CO 2 , VOC, humidity, temperature and explosive substances, in order to monitor constantly the internal air quality. These data can even be transmitted to a control unit in cloud.

[0080] The distinctive feature of the control unit 2 lies in the extraordinary versatility, by allowing the integration of a wide number of additional sensors.

[0081] In particular, the proposed solution adopts the multiplexing technique to expand significantly the number of connectable sensors. For example UART or ADC in multiplexing allow to share one single digital or analog communication line with numerous sensors, allowing the microprocessor to select dynamically the sensor desidered for communication. This approach not only reduces considerably the number of pins required on the microprocessor but also eases the connection of a wide range of air quality sensors.

[0082] In order to guarantee the duration over time of sensors, the microprocessor manages the cyclic power-on and power-off of the sensors by acting on the power supply. This process balances the need for acquiring accurate data with the energy efficiency and longevity of the sensors. The operating cycle of the control unit starts with sensors' powering-on and with a waiting period for stabilizing reading, followed by the sequential reading of all active sensors, reaching to read even 300 sensors per minute. The activation, reading and deactivation frequency of the sensors is regulated in order to find an equilibrium between the sampling frequency and the energy saving, by ensuring a useful life of the sensors of at least five years.

[0083] The control unit connects to the cloud via WiFi networks, allowing the transmission of air quality data and the operation of the electromechanical device. In this way the users can access the historical data and in real time through mobile applications or web platforms. The connection to the cloud offers advantages such as the information sharing, the real time analysis and remote software updating to improve functionality and safety.

[0084] The electronic control unit communicating infrastructure with cloud uses wireless networks at 2.4GHz and 5GHz, or details the wireless communication between the control unit which communicates with all devices for the exchange of air and heat and the mobile devices, for example tablet or smartphone, apart from the connection to the cloud. Through web platforms connected to the cloud, the users can monitor the environmental data wherever they are, by guaranteeing a complete and immediately accessible vision of the internal environment.

[0085] Figure 2 has a flow chart relating to the operation of the invention in presence of generic polluting gases: the control unit detects not explosive pollutants with deviation of the air quality from the programmed standard and commands the fans to exchange air at moderate speed, but proportioned to the amount of pollutants.

[0086] Figure 3 illustrates a flow chart relating to the operation of the invention in presence of explosive gases: the sensors integrated in the control unit detect the presence of explosive gases. In response to this detection, the control unit commands the fans of the exchanger to start the air exchange at the maximum speed, thus preventing the risks of explosion (not infrequent and with several damages and deaths). In this situation, the exchange takes place quickly, with priority to safety instead of thermal efficiency. In both cases the electromechanical device regulates the ventilation of the environment based on the presence of polluting gases.

[0087] The system is devised to ensure an energy recovery thermal efficiency higher than 90%, with the exchange surface of the graphene sheet calculated based on the room size, on the need for air exchange and the characteristic risk of the controlled room; the exchange surface of the graphene membrane piping in a standard model was calculated around 1.5 mq.

[0088] The thermal conductivity of the material of the electromechanical device for the air exchange with heat recovery is considered between 1,200 W / mK and 1,500 W / mK, with an exchange surface of 1 square meter.

[0089] By using the thermal conductivity values, the exchange area and the temperature difference between the two air flows, the hourly exchange volume and the thermal efficiency of the electromechanical device for the air exchange with heat recovery is calculated.

[0090] The temperature values of the internal and external air, together with the temperature difference between the two flows, are used to calculate the specific heat of air and the exchange surface.

[0091] The software of the control unit regulates the speed of the fans based on the urgency of the air requirement. In case of emergency, the fans rotate at the maximum speed to reduce the risk of accidents, explosions or poisonings. Under normal conditions, the heat exchange is slowed down to maximize the thermal energy recovery.

[0092] In both above-mentioned cases the operating cycle of the control unit starts with programming the power-on of the sensors, followed by a waiting period intended to allow to stabilize their reading. This waiting phase is essential to allow the sensors to reach a stable or equilibrium state known as "stabilization". In fact many sensors are sensitive to temperature and their optimum operation is reached at the thermal regime. This wait avoids inaccurate or misleading readings. Subsequently to the stabilization step, all active sensors are read and then the sensors are selected one at a time and queried sequentially.

[0093] By working on UART at the minimum communication speeds of 9600 bps (bit per second) and considering maximum packets of 150 byte, in one second the system can query surely more than six sensors. By considering even other factors, such as the real sensor interrogation time for managing the collisions and the response time of each sensor, the read sensors will be surely more than 5. Moreover, the sensors operating on I2C bus or on ADC analog line in multiplexing, can be read parallelly with those on UART bus in multiplexing and then the reading speed of the sensors increases. In one minute even three hundred sensors at a time can be read.

[0094] After having acquired the required data, the sensors are electronically powered-off.

[0095] This power-on, stabilization, data acquisition and power-off cyclic process is repeated cyclically, by guaranteeing an optimum equilibrium between the precision of reading, the energy efficiency and the preservation of the operating life of the sensors in the long run.

[0096] The determination of the activation frequency of the sensors is managed by a process which tries to find an equilibrium between the need for sampling frequently and the need for saving energy and / or prolong the operating life of the sensors.

[0097] The maximum variation obtained from the comparison of all sensors represents the maximum possible variation, except for some specific sensors, such as those to detect explosive and hazardous gases, which have to remain constantly active for safety reasons.

[0098] The control unit keeps track of the operating hours of each sensor and warns the user when it is necessary to replace one based on the accumulated operating hours.

[0099] The maintenance of sensors can be performed easily by the user and each time a sensor is replaced, the control unit software re-sets automatically the operating hours. The connection to the cloud offers different advantages, thereamong the sharing of information, the analysis in real time and the possibility of updating remote software to improve continuously functionality and safety of the system.

[0100] Thanks to the capability of analysing large amounts of information, the cloud identifies tendencies and anomalies in the internal environment, by providing informed decisions and preventive actions. The cloud can optimize the system by using historical data and information about the performance, by suggesting aimed improvements. In a broader operational vision, there will be numerous users and control units connecting to the same cloud (or to several clouds if several users are present).

[0101] Each control unit is identified by a unique serial code, guaranteeing that each user can only access the information of the control units for which he / she is authorized. In presence of anomalies in the air quality, the cloud can send timely notifications to users to keep them informed.

[0102] The control unit is capable to operate autonomously even in absence of connection to cloud; however, the cloud can provide useful indications to optimize performance of the control unit and even to command it remotely.

[0103] The control unit is capable of communicating with the electromechanical device for the air exchange with heat recovery when exceeding of the indoor air quality parameters takes place.

[0104] The electromechanical device for the air exchange with heat recovery represents an effective solution to manage the internal air quality without compromising the energy efficiency; by using the heat recovery, the device captures heat from the exhaust air and uses it to preheat or precool incoming fresh air, by reducing the energy losses associated to the air exchange.

[0105] The two temperature sensors present inside the electromechanical device for the air exchange monitor precisely the temperatures of the air incoming and outgoing from the system. These sensors provide useful data to calculate the temperature difference between the indoor exhaust air and the incoming fresh air. The temperature difference value is fundamental to regulate the speed of the fans so as to maximize the heat recovery: during the colder months, the hotter exhaust air can be used to preheat the incoming air, whereas during the hotter months it can be used to pre-cool it.

[0106] The adaptability to specific needs represents an additional advantage, since the system modules dynamically the air flow speed based on needs. By regulating dynamically the fan speed based on the measured value of the temperature difference, the system can operate more effectively, by reducing the energy consumption and maximizing the overall efficiency of the ventilation and heat exchange system. Moreover, the fan speed varies dynamically in response to the variations of the values detected by the sensors. This approach is known as "feedback control" and allows the system to adapt in real time to the detected environmental conditions. For example, if one sensor detects a decrease in the oxygen levels in air below a preestablished threshold, the system can activate the fans at a lower speed in order to increase the air exchange and to improve the oxygen concentration. If the oxygen levels reach a critical threshold, the system can increase drastically the fan speed to re-establish the situation quickly. This dynamic control strategy can be extended to other environmental parameters detected by the sensors, such as temperature, humidity, presence of suspended particles (PM), and so on. The goal is to keep constant the air quality parameters within the wished limits by regulating the fan speed based on the specific needs detected by the sensors.

[0107] In environments with reduced sizes, ventilation occurs with a lower fan speed to avoid excessively rapid variations in the air parameters. Besides, in wider spaces, the fans will operate at higher speeds to guarantee an adequate air exchange. Even the presence of a higher number of people in a room has a significant impact on the air quality due to the CO 2 emissions and of the breathing action. In case of a high number of occupants, the fan speed has to increase to compensate the additional emissions. For wide and / or crowded environments, it is possible to implement several air exchangers and several control units for measuring the air quality. The configuration, like the number of air exchangers or measuring control units, is not rigid and can be adapted dynamically based on specific needs. This means that it is not necessary to have a control unit for measuring air and a heat exchanger in each environment; the number of control units and exchangers can be varied depending upon size and features of spaces, by guaranteeing an optimum flexibility in system design.

[0108] The goal of limiting drastically the heat energy consumption related to the achieved air exchange, in case of not explosive pollutants, by exchanging air at low speed, focuses on energy efficiency and reduced environmental impact in the field of air exchange by underlying the need for overcoming inefficiencies and limits of previous solutions, which not only did not guarantee an optimum internal air quality, but also offered a modest energy recovery.

[0109] The proposed solution is based on a more sophisticated system, which exploits the principle of the countercurrent air flow to maximize the exchange of thermal energy between the outgoing air and the incoming one. This solution incorporates several key features: use of graphene: this material with high thermal conductivity is used to optimize the heat recovery during the air exchange; modulation of the air exchange speed: the system regulates the air flow speed based on needs; when there are dangerous contaminants, the system gives priority to safety by increasing the air exchange speed to remove quickly the risks, even at the cost of lower energy recovery, on the contrary, when the pollutants have a long-term impact, the system adapts the air flow speed so as to maximize the energy recovery, while maintaining an acceptable air quality; continuous monitoring of the air quality: the electronic control unit constantly monitors the air quality, by detecting the presence of dangerous contaminants and acting consequently to guarantee a safe and healthy internal environment.

[0110] The described system has a series of advantages facing effectively various challenges relating to the internal air quality and energy efficiency.

[0111] Among the offered advantages, it is to underlined the continuous monitoring of the internal air quality. Through an electronic control unit and integrated sensors, the system ensures a constant control of the air quality, by guaranteeing a comfortable and safe environment for the occupants.

[0112] The safety of the occupants is also ensured possibly through acoustic and visual signals in case of health risks due tot the presence of dangerous contaminants, by providing a timely indication to users for rapid intervention.

[0113] Moreover, the system contributes significantly to decrease the thermal energy consumption associated to the air exchange. This is made possible thanks to the thermal energy recovery during the countercurrent air exchange, which translates into a considerable energy saving.

[0114] The connection to cloud allows to monitor remotely the air quality and the access to data in real time, by facilitating timely interventions in case of anomalies and allowing software updating to improve constantly functionalities and safety of the system. The present invention describes even the operating process of the integrated system 100 for ensuring tee a predetermined optimal quality of confined air comprising the following phases: activating at least a first process for power-on, data acquisition and power-off the sensors 2.8, 2.9. and 2.10; processing by the electronic control unit 2 of the data coming from said sensors 2.8, 2.9. and 2.10 per unit of time; activating at least a second process for power-on, data acquisition and power-off the sensors 2.8, 2.9. and 2.10; calculating the frequency of the detections exceeding a predetermined threshold value; commanding the regulation of the speed of fans 1.2, 1.6 of the electromechanical device 1 based on said variation of the values of the detected parameters and based on the frequency of the detections exceeding a predetermined threshold value.

[0115] When the frequency of the detection exceeding a predetermined threshold value reaches a threshold value, the control unit 2 commands the electromechanical device 1 to increase the speed of fans which will be greater the higher the frequency of the detections of said pollutant and / or hazardous gas.

[0116] The process even provides the following additional phase of commanding one or more programs of air exchange cycles in the time unit in order to ensure a predetermined optimal quality of the confined air based on one or more detected parameters exceeding a predetermined threshold value.

[0117] The activation, reading and deactivation frequency of the sensors 2.8, 2.9. and 2.10 is modulated based on the frequency of detections of values exceeding a predetermined threshold value.

[0118] In case of detection of at least one value exceeding a predetermined threshold value, the time period between two power-on, data acquisition and power-off of said sensors 2.8, 2.9. and 2.10 is comprised between 10 and 50 sec, preferably 30 sec, on the contrary when normal values are detected, the period of time between two power-on, data acquisition and power-off processes of said sensors 2.8, 2.9. and 2.10 is comprised between 3 and 10 min, preferably 5 min.

[0119] The operation process of the integrated system also comprises the following phases which allow to recover heat during the air exchange: processing data coming from said temperature sensors 1.13, 1.14; calculating the temperature difference between the air coming from outside and the purified incoming air; commanding the regulation of the countercurrent air flow speed by means of said graphene membrane 1.3. so that the countercurrent flows exchange heat so that the temperature of the incoming air is equal to that of the outgoing air.

[0120] When the presence of an explosive gas is detected by said sensors 2.8, 2.9. and 2.10, the control unit commands the electromechanical device a maximum speed of the air flows by reducing to the minimum the countercurrent heat exchange so as to prioritize safety.

[0121] In conclusion the integrated system and its operation process offer a complete solution for ensuring an optimum internal air quality and to reduce the energy consumption, with significant advantages in terms of health, comfort and environmental sustainability.

[0122] The object of the invention is likely to be subjected to several modifications and variants, all within the inventive concept expressed in the enclosed claims.

[0123] The embodiments and the embodiment details could be widely varied with respect to what has been described and illustrated by pure way of not limiting example, without leaving, for this, the protective scope of the present invention.

[0124] Even if the object has been described with particular reference to the enclosed figures, the reference numbers used in the description and claims are used to improve the understanding of the invention and do not constitute any limitation to the scope of claimed protective scope.

Claims

1. An integrated system (100) for ensuring a predetermined optical quality of confined air and for preventing risks arising from the presence of hazardous gases to the minimum energy cost, consisting of: - an electromechanical device (1) for the exchange of air and heat, comprising: ∘ an internal dispenser / expeller (1.1); ∘ at least a graphene membrane configured so as to increase the exchange surface (1.3) ∘ at least a fan (1.2; 1.6); ∘ at least two filters, at least one thereof capable of cleaning the air from the physical particles of pollutants and at least one capable of cleaning the air from microbiological contaminants; ∘ an external expeller / extractor (1.7); ∘ flow separators (1.8, 1.9); ∘ an external piping (1.10) consisting of a heat-insulating tube with variable thickness based on the thermal areas, and an internal piping (1.11) consisting of a heat-conducting tube acting as flow separator; ∘ temperature sensors (1.13, 1.14) positioned at the air inlet and outlet and suitable to detect the temperatures of the air entering and leaving the electromechanical device (1); ∘ a communication antenna; - a control unit (2) monitoring the air quality inside a confined environment, comprising: ∘ a high-efficiency universal switching power supply (2.1); ∘ a microcontroller (2.2); ∘ a communication antenna (2.3); ∘ an air recirculation fan (2.4); ∘ a digital switch to provide power to the sensors (2.7); ∘ at least one analog sensor (2.8) to detect at least one value relating to at least an air quality parameter and / or an explosive gas; ∘ at least one digital sensor (2.9) to detect at least a value relating to at least a pollutant and / or an explosive gas and for asynchronous communication with said electromechanical device (1); ∘ at least one digital sensor (2.10), to detect at least one value relating to at least a pollutant and / or an explosive gas and for synchronous communication with said electromechanical device (1) ∘ a timer, characterized in that said control unit (2) is configured to process the data coming from said sensors (2.8, 2.

9. and 2.10) per unit of time, to calculate the frequency of detections of values exceeding a predetermined threshold value and to regulate the speed of the fans (1.2, 1.6) of said electromechanical device (1) and to process the data coming from said temperature sensors (1.13, 1.14) and to calculate the temperature difference between the exhausted indoor air coming out and the purified external air coming in and to regulate the countercurrent air flows, and in that said electromechanical device (1) is configured to expel air present inside a confined environment at variable speeds and to introduce air from outside at variable speeds, cleaning it by means of at least two filters (1.5.1; 1.5.2), and in that it is configured to recover the thermal energy by regulating the countercurrent air flows by means of said graphene membrane (1.3) based on the commands received from said electronic control unit (2).

2. The integrated system according to claim 1, characterized in that said control unit (2) is configured to regulate dynamically the speed of the fans based on the values of the parameters detected by said sensors (2.8, 2.

9. and 2.10) in relation to the presence of at least a pollutant and / or an explosive gas, based on the frequency of the detections exceeding a predetermined threshold value and to command one or more air exchange cycles per unit of time in order to ensure a predetermined optimum quality of confined air.

3. The integrated system according to claim 1, characterized in that the graphene membrane piping (1.3) has a heat exchange surface proportional to air exchange requirement of the controlled environment, by guaranteeing a thermal conductivity between 1.200 W / mK and 1.500 W / mK.

4. The integrated system according to claims 1 and 3, characterized in that the graphene membrane piping (1.3) has a micrometric thickness and shape so as to determine a star-like section in order to maximize the heat exchange surface in the minimum space.

5. The integrated system according to any one of claims 1, 3 and 4, characterized in that the graphene membrane piping (1.3) has a variable exchange surface calculated based on the room size and on the need for air exchange.

6. The integrated system according to claims 1 and 2, characterized in that the analog sensors (2.8) and the digital sensors (2.9, 2.10) are connected through a multiplexer controlled by the microcontroller (2.2), allowing the connection of a high number of additional sensors.

7. The integrated system according to claim 1 and 6, characterized in that the activation, reading and deactivation frequency of said sensors (2.8, 2.

9. and 2.10) is modulated based on the frequency of detections of values exceeding a predetermined threshold value.

8. The integrated system according to claim 1, characterized in that the electronic control unit (2) manages the wireless communication with external devices at frequencies of 2.4GHz and 5GHz and it communicates with cloud via WiFi networks, allowing the transmission of air quality data and the operation of the electromechanical device (1) and allowing the remote monitoring and the software updating.

9. An operation process of the integrated system (100) for ensuring a predetermined optimum quality of confined air according to claims 1 to 8 comprising the following phases: - activating at least a first process for power-on, data acquisition and power-off the sensors (2.8, 2.

9. and 2.10); - processing data coming from said sensors (2.8, 2.

9. e 2.10) per unit of time by the control unit (2); - activating at least a second process for power-on, data acquisition and power-off the sensors (2.8, 2.

9. and 2.10); - calculating the frequency of detections exceeding a predetermined threshold value; - commanding the regulation of the speed of fans (1.2, 1.6) of the electromechanical device (1) based on said variation of the values of the detected parameters and based on the frequency of the detections exceeding a predetermined threshold value, characterized in that when the frequency of the detections exceeding a predetermined threshold value reaches a threshold value, said control unit (2) commands said electromechanical device (1) to increase the speed of fans which is greater than higher is the frequency of the detections of said pollutant and / or hazardous gas.

10. The operation process of the integrated system according to claim 9 characterized in that it comprises the following additional phase: - commanding the electromechanical device (1) one or more programmes of air exchange cycles per unit of time in order to ensure a predetermined optimum quality of confined air based on one or more detected parameters exceeding a predetermined threshold value.

11. The operation process of the integrated system for ensuring a predetermined optimum quality of air according to claims 9 and 10 comprising the following phases: - processing data coming from said temperature sensors (1.13, 1.14); - calculating the temperature difference between the exhausted air present inside and exiting and the incoming purified air from the outside; - commanding the electromechanical device (1) the adjustment of the speed of the countercurrent air flows by means of said graphene membrane (1.3), characterized in that the countercurrent flows exchange heat so that the temperature of the incoming purified air is equal to that of the outgoing exhausted air.

12. The operation process of the integrated system to guarantee a predetermined optimum quality of air according to each one of the preceding claims characterized in that when the presence of an explosive gas is detected by said sensors (2.8, 2.

9. and 2.10), the control unit (2) commands the electromechanical device (1) to reach a maximum speed of the air flows by reducing to the minimum the countercurrent heat exchange.

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