Incoming Air Research Articles

Performance prediction for modified design of dew point evaporative cooler for air cooling

ABSTRACT Traditional air conditioning systems use lot of energy; thus, dew point evaporative air-cooling systems could be a good alternative. Many experts studied the impact of constructional and operating characteristics on Maisotsenko cycle (M-cycle) to improve its performance. Cooler performance is influenced by the heat exchanger. Heat exchangers were constructed using flat and corrugated plates. The present study proposes the use of geometrically modified trapezoidal corrugated plates for counter flow heat exchanger, which consists of alternate air and water flow passageways. The numerical model is developed to predict the performance under variety of inlet air conditions and channel dimensions. In the standard range of incoming air properties such as relative humidity, the performance parameters assist in making cooler recommendations. Comparison and validation of simulation results are done with published experimental data for corrugated and trapezoidal corrugated plate heat exchangers. For trapezoidal corrugated plates, simulation findings revealed 10% increase in wet bulb efficiency and 7% increase in dew point efficiency over corrugated plates. The efficiency of wet bulb and dew point decreases as channel gap widens. For trapezoidal corrugated plates, the larger channel spacing minimises pressure drop.

Validation of Extrapolation of Test Performance for Air-to-Air Rotary Energy Exchangers (ASHRAE RP-1799)

Air-to-air energy exchangers are used in buildings to transfer energy between the exhaust air and the incoming outdoor air. Typically, the performance of air-to-air energy exchangers is tested, rated and certified according to industry-accepted standards and procedures. Because of the expenses and facility constraints associated with laboratory testing, performance rating tests of air-to-air energy exchangers are usually performed at a limited number of test conditions for selected products. This paper uses laboratory tests to validate the extrapolation approaches available from the literature. Two sets of air-to-air energy wheels from different manufacturers were tested at the energy recovery testing facility of Intertek. Each set included three wheels of different sizes (i.e., small, medium, and large). The analysis of test results showed an overlap in performance ratings between different wheel sizes after accounting for allowable allowances, which in turn supported the extrapolation approach used by the Air-Conditioning, Heating, and Refrigeration Institute for performance rating. By comparing the test results with the results from the selected effective correlations, it was found that axial heat conduction should be considered when applying the numerical heat and mass transfer models for energy wheels.

Impacts of Social Inequality, Air Pollution, Rural-Urban Divides, and Insufficient Green Space on Residents' Health in China: Insight from Chinese General Social Survey Data Analysis.

Attention to physical and mental health is becoming more intensive. In China, factors and mechanisms are now a focus of research. We used dynamic air quality monitoring data and the Chinese General Social Survey (CGSS) to assess the spatial differences and the coupling between subjective and objective air pollution. In addition, a logistic model was used to explore the impact mechanisms of social inequality, air pollution, food safety, and lack of green space on health. The results show that (1) the impact of subjective and objective air pollution on the health level of the population is significant; (2) income inequality, air pollution, food pollution, and travel behavior significantly affect the residents' health; and (3) environmental health has a significant differentiation mechanism between urban and rural areas. The negative health effects of air pollution and insufficient green space are more significant in cities; food pollution is more likely in rural areas. In terms of socioeconomic inequality, gender, family size, travel, and physical exercise had no significant effect on rural health. Health improvement was higher in the low-income group than in the high-income group. The adverse effect of travel behavior on environmental pollution is conducive to improving health. Therefore, social equality, strictly controlled environmental pollution, exercise, and travel can help narrow the gap between rich and poor, promote urban-rural health equity, and improve human health.

Continuous, High Efficiency Defrosting of Air-to-Air Heat Pumps

This study aims to realize continuous, high efficiency defrosting of air-to-air heat pumps using the effect of outdoor warm air recycling, trying to improve the coefficient of performance (COP) and total heat capacity of traditional defrosting methods like hot bypass and Joule heating. The proposed patented method recovers heat from the air change system by mixing the warm discarded air with the incoming air of the external heat exchanger. The fan of the external unit sucks the indoor air with the depression obtained by a Venturi. The warm air is ducted to the Venturi through a hole in the wall. The amount of warm air mixed to the outside air is regulated by a butterfly valve installed on the pipe from the hole to the Venturi. In this way, the air entering the external coil is warm enough to avoid frost. The energy efficiency of the system is assured, for the warm indoor air is heated with the high COP of the heat pump. Our system can achieve defrosting with a limited amount of warm air, and realize a higher overall COP than the best traditional defrosting systems. Finally, the defrosting device can be added as an option to any existing split systems.

Rotors of Vertical-Axial Wind Turbines Assembled in Bearings and Aerodynamic Characteristics of a Blade with Unclosed Wing Profile

Abstract In world practice, traditional blades used in high-speed wind turbines, both horizontal-axial and vertical-axial, have a wing-shaped profile. However, for horizontal-axial wind turbines, blades with such a profile have a fairly narrow range of operating values of the angle of attack of the incoming air flow and a low value of the moment of pulling from place. As for vertical-axial wind turbines, the self-starting of the rotor with wing blades is completely absent and additional devices are needed to start the rotor into operation. In order to ensure the self-starting of the rotor and the operation of the wind turbine at high and low wind speeds, a new shape of the blade profile was developed, called non-closed wing profile. The concept of the development is that the blade should have a configuration in which the pulling force is involved at the beginning of the movement, and then, with the establishing of the movement, a lifting force would arise, which acquires a prevailing character in the operating mode. The article presents the results of experimental studies of the aerodynamic characteristics of the developed non-closed wing blades. One of the results obtained is to determine the effect of the thickness of the blade profile on the range of values of subcritical angles of attack of the incoming air flow and the differences between the nature and range of changes in the coefficients of lifting force and pulling force in a traditional wing blade and a blade with a non-closed wing profile. Studies of the rotor model of a vertical-axial wind turbine with non-closed wing blades have confirmed the presence of its self-starting and operability even at low wind speeds.

Air circulation study inside and outside of urban buses induced by the opening of windows.

In this work, the external and internal airflow analysis in an urban bus is carried out through computational fluid dynamics. The research addresses the study of the internal flow to estimate the air change rate caused by the opening of windows. Two cases are considered: fully opening and partially opening the windows, and three bus speeds of 20, 40, and 60 km/h are assessed. The quantification of the air flow rate through the windows clearly displays that air enters through the rear windows and exits the bus through the front windows. This effect is explained by the pressure distribution in the outer of the bus, which causes the suction of the indoor air. At low bus speeds, the incoming air flow rate increases linearly with the speed, but the improvement is lower for high speeds. The theoretical air change time at 20 km/h is around 25.7 s, which is 9 times lower than expected by using HVAC systems. On the other hand, the estimation of the real air renewal time by solving a concentration shows that 40 s are needed to exchange 85% of the internal air of the bus. The research also assesses the effect of different levels of occupation inside the bus. Results are conclusive to recommend the circulation with full or partial window opening configurations in order to reduce the risk of airborne disease transmission.

Analysis of Secondary Particles as a Complement to Muon Scattering Measurements

Cosmic ray tomography is an emerging imaging technique utilizing an ambient source of radiation. One common tomography method is based on the measurement of muons scattered by the examined objects, which allows the reconstruction and discrimination of materials with different properties. From the interaction of air shower particles induced through cosmic rays with the material to be scanned, secondary particles, predominantly photons, neutrons and electrons, can be produced, which carry complementary information about the objects and their materials. However, this information is currently not fully exploited or only studied in coincidence with the incoming air shower particles. Therefore, this work presents a novel approach utilizing only the information from secondary particles to reconstruct and discriminate objects made out of a variety of materials. It also includes a detailed analysis of the kinematics of secondary particles and their dependency on material characteristics. In addition, a reconstruction algorithm to produce 3D maps of the examined volume from the measurement of secondary particles is introduced. This results in a successful reconstruction and differentiation of objects in various geometrical compositions.

Energy Output of High‐speed Flowing Two‐phase IPN/Air in the Combustion Chamber

AbstractFuel‐air cloud explosions or detonations are often affected by initial ambient conditions. A two‐dimensional (2D) semi‐confined model was established to study the effects of the inflowing air temperature and initial temperature of the combustor on the explosion process of isopropyl nitrate (IPN)/air mixture. The results showed that at different initial temperatures (1000–3000 K), the first peak pressure (P1) and second peak pressure (P2) decreased with the increase in initial temperature; the maximum flame temperature (2338–3534 K) increased with the increasing initial temperature; the explosion pressure and temperature had the opposite trends with the initial temperature, indicating that the oxygen content in the combustor had a greater impact on the explosion pressure, while the initial temperature had a more significant effect on the flame temperature. Under different incoming air temperatures (1000–3000 K), the flame temperature (∼2700 K) of the two‐phase explosion had a small difference at the incoming temperature of≤2500 K, signifying that the airflow temperature (<3000 K) and the oxygen content in air jointly dominated the flame temperature; the flame temperature was 3100 K at the incoming temperature of 3000 K, which was about 300 K higher than other incoming flow temperatures, indicating that the flame temperature was more sensitive to the incoming air temperature (≥3000 K). At 600 m/s airflow, the explosion parameter curves at the inflow temperatures of 300 K and 600 K were compared, and the critical inflow temperature of the explosion process was also investigated.

Effects of cavity length on operating characteristics of a ramjet rotating detonation engine fueled by liquid kerosene

Our very recent work has experimentally demonstrated the successful operation of a liquid-kerosene-fueled ramjet/air-breathing rotating detonation engine with a cavity-based annular combustor. As a follow-up study, the present work aims to further reveal the effects of cavities on the initiation and propagation characteristics of detonation, and various cavity lengths ranging from 30 mm to 90 mm were employed in the combustor. An air-heater was designed to provide an incoming flow at a total temperature of 860 K, which resembles the specific flight Mach number of 4 at an altitude of 20 km. The total mass flow rate of the incoming air flow was kept at 1.0 kg/s. The results indicate that a sufficient cavity length, which is found to be around 45 mm in minimum, is necessary to achieve the successful initiation of the rotating detonation waves. By increasing the cavity length to 75 mm and 90 mm, the fuel-lean detonation limits in terms of equivalence ratios (ER) can be extended from 0.8 to 0.7. The maximum propagation stability and minimum velocity deficit of 39.1 % (with respect to the ideal Chapman-Jouguet velocity) were achieved when the cavity length was 75 mm with the ER of 0.95. The optical observation indicates that detonation mainly occurs downstream of the cavity. The detonability of the kerosene/air mixture can be enhanced by the preheating of the permanent flame, and better enhancement is provided by larger cavity lengths. However, when the cavity length reaches 90 mm, part of the mixture is pre-ignited and consumed by deflagration. Therefore, the propagation velocity and stability of the rotating detonation wave increase as the cavity is lengthened from 45 mm to 75 mm, while showing a decrease when the cavity length reaches 90 mm. It is suggested that better detonation performance can be achieved by placing the permanent flame in a proper axial position through changing the cavity length. In addition, the increase of the cavity length is beneficial to alleviate the disturbance of the upstream oblique shock wave on the incoming flow in the isolator.

The impact of air travel on the precocity and severity of COVID-19 deaths in sub-national areas across 45 countries

Human travel fed the worldwide spread of COVID-19, but it remains unclear whether the volume of incoming air passengers and the centrality of airports in the global airline network made some regions more vulnerable to earlier and higher mortality. We assess whether the precocity and severity of COVID-19 deaths were contingent on these measures of air travel intensity, adjusting for differences in local non-pharmaceutical interventions and pre-pandemic structural characteristics of 502 sub-national areas on five continents in April–October 2020. Ordinary least squares (OLS) models of precocity (i.e., the timing of the 1st and 10th death outbreaks) reveal that neither airport centrality nor the volume of incoming passengers are impactful once we consider pre-pandemic demographic characteristics of the areas. We assess severity (i.e., the weekly death incidence of COVID-19) through the estimation of a generalized linear mixed model, employing a negative binomial link function. Results suggest that COVID-19 death incidence was insensitive to airport centrality, with no substantial changes over time. Higher air passenger volume tends to coincide with more COVID-19 deaths, but this relation weakened as the pandemic proceeded. Different models prove that either the lack of airports in a region or total travel bans did reduce mortality significantly. We conclude that COVID-19 importation through air travel followed a ‘travel as spark’ principle, whereby the absence of air travel reduced epidemic risk drastically. However, once some travel occurred, its impact on the severity of the pandemic was only in part associated with the number of incoming passengers, and not at all with the position of airports in the global network of airline connections.

Numerical and experimental investigation of desiccant cooling system using metal organic framework materials

• Modelling of stationary desiccant wheel coated with different metal organic framework adsorbent materials (MIL-100(Fe), MIL101(Cr), CPO-27(Ni), Aluminium fumarate). • Develop new equilibrium equations from the isotherms related to these MOFs. • New experimental data and numerical data for stationary honeycomb desiccant wheel coated with Aluminium Fumarate was generated. • MOF materials coating process and performance comparisons with different humidifier air speeds. Evaporative cooling consumes fraction of the electricity required by the vapour compression refrigeration system but is only effective in dry weather conditions. A promising method for controlling the incoming air humidity is to use a desiccant wheel before the evaporative cooler. Currently, most desiccant cooling systems employ conventional materials like silica gel or zeolites which have low water uptake. Metal Organic Framework (MOF) materials are new class of meso -porous material with high water adsorption capabilities (∼1.5 kg/kgads). Using numerical modelling and experimental testing, this paper investigates the use of four MOF materials namely CPO27(NI), MIL100(Fe), MIL-101(Cr), Aluminium Fumarate and silica gel on the performance of a stationary desiccant heat exchanger (honeycomb Aluminium structure coated with MOF desiccant material) in terms of the Coefficient of performance (COP) and moisture removal rate. Numerical results showed that Aluminium fumarate produced the highest COP of 0.65 with water removal rate of 12.65 g/kg dry air and MIL-101(Cr) produced the highest moisture removal of 15.99 g/kg dry air but with COP of 0.44 compared to silica gel and other MOF materials used. Experimental tests were carried out using honeycomb structure coated with Aluminium fumarate as the stationary desiccant wheel and results were compared to numerical modelling showing good agreement with maximum deviation of 13%. Experimental and modelling results showed that the rate of moisture removal increases with the increase of air inlet humidity and with the decrease of incoming air speed. Also, results showed that the highest moisture removal occur after the first 2 min from starting the dehumidification process highlighting the advantage of using MOF materials.

Performance study of a pre-cooled turbo-rocket combined engine under a wide Mach number of 0~5

In view of the urgent demand for wide speed range and high-performance power for next generation aircraft, near space multi-functional platform and the first stage of TSTO (two-stage-to-orbit) transportation system, this paper timely puts forward an innovative turbo-rocket combined cycle propulsion scheme named NUAA-PTRE (Pre-cooled Turbo-Rocket Engine designed by Nanjing University of Aeronautics and Astronautics) under Ma 0–5. In the scheme, hydrocarbon fuel at normal temperature is employed to pre-cool incoming air, and the chemical heat sink of fuel cracking is utilized sufficiently, which expends flight Mach number range of aircraft effectively. In this paper, the performance characteristics of the engine such as thrust, specific impulse under Ma 0–5 and 0–30km in the flight envelope are studied. The influence of air pre-cooling on the performance at Ma 4–5 is evaluated. This paper points out that the pre-cooling of incoming air by pyrolysis of endothermic hydrocarbon fuel above Ma 4/880 K can broaden the working Mach number range of the engine and improve the performance of the engine at high Mach number. The pre-cooled turbo-rocket combined cycle propulsion scheme of NUAA-PTRE, proposed in this paper meets the working requirements of full speed range from Ma 0–5 and full airspace from 0–30 km, and can be used to support the application of next generation aircraft.

Optimizing relative humidity based on the heat transfer terms of the thermoelectric atmospheric water generator (AWG): Innovative design

The main objective of this study is to optimize relative humidity based on the heat transfer terms of thermoelectric atmospheric water generator from moisture in the air. The experimental thermoelectric atmospheric water generator is maintained with a 0.04 × 0.04 m2 thermoelectric cooler that can condense water vapor. The analysis shows that electricity, air mass rate, relative humidity, and incoming air temperature affect the quality and quantity of water produced from the atmosphere. The results show that increasing atmospheric moisture at a constant temperature rises the amount of water produced from the atmosphere. It is concluded that a thermoelectric AWG designed with thermos electric cooling as an electric condenser has excellent potential as a kind of power generation through renewable energy sources from the atmosphere.On the other hand, the conducted tests show that by reducing the temperature of the cooling water, the amount of produced water and the efficiency of the device increase. While the temperature of inlet air is 37 °C, the humidity is 95 %, and the electric current intensity of thermoelectric is 1 A, the amount of generated water reached 96 ml h−1. The amount of water generated for the experimental device equals 82 ml h−1.

Numerical Analysis of Ventilation Efficiency of a Korean Venlo-Type Greenhouse with Continuous Roof Vents

A Venlo-type greenhouse with a continuous roof vent (CR-Venlo greenhouse) was proposed by the Ministry of Agriculture, Food and Rural Affairs, South Korea (2019) for natural ventilation even during summers. It is ventilated through the buoyancy effect of the heated air using the high eave elevation. However, the CR-Venlo greenhouse was not distributed domestically, and its ventilation efficiency was not quantitatively evaluated. We aimed to analyze the natural ventilation efficiency of the greenhouse according to the eave height, using computational-fluid-dynamics. The simulation model was analyzed for hot summer conditions. The target greenhouse is ventilated only through the roof vent with all roof windows open; therefore, the air introduced through the roof window is easily exhausted. To evaluate the efficiency of ventilation, the external air entering through the roof window was calculated and evaluated. The amount of incoming air varied greatly with the location of the span and average temperature of the greenhouse; The temperature of the crop zone decreased lognormally with increasing height of the eave. Moreover, the ventilation efficiency of CR-Venlo greenhouse could be increased by improving the ventilation structure such as a shape, position or combination of roof window.

An exploration of solar-induced chlorophyll fluorescence (SIF) factors simulated by SCOPE for capturing GPP across vegetation types

Solar-induced chlorophyll fluorescence (SIF) has been regarded as proxy data of vegetation photosynthesis; thus, it is assimilated into the terrestrial carbon cycle modeling. The Soil Canopy Observation of Photosynthesis and Energy fluxes (SCOPE) model is one of the most utilized models of SIF simulation. However, the currently incomplete understanding of SCOPE SIF factors and the lack of exploring how SCOPE works under different vegetation types would deteriorate further carbon cycle research. Herein, this study disentangled decisive SIF factors in the SCOPE model; then, a sample SIF dataset (SynSIF), with spatial resolutions of both 0.02∘ and 0.05∘, was simulated through SCOPE model using factors above. Then this study validated how far SCOPE simulating SIF could capture GPP, compared with other SIF datasets. The results showed that: (1) There are five decisive SIF factors in SCOPE model, including plant status (leaf chlorophyll content and leaf area index) and meteorological parameters (incoming shortwave radiation, air temperature, and atmospheric vapor pressure). (2) The linear relationship of SynSIF-GPP outachieved other SIF datasets across all six vegetation types in southern South America, Asia, and Africa, improving R2 averagely by 0.33, 0.28, and 0.15, respectively. (3) SynSIF in Oceania and Europe, revealing GPP better in shrublands (with SynSIF-GPP R2 increasing by 0.15 and 0.16, respectively) and grasslands (with SynSIF-GPP coefficients increasing by 0.14 and 0.06, respectively), illustrated spatially complementary characteristics with GOSIF across varying vegetation types. Thus, we anticipate that this study could provide more complete information for SCOPE simulating SIF in different biome research when estimating the terrestrial carbon cycle.

Numerical Investigation of the Adsorption Process of Zeolite/Water in a Thermochemical Reactor for Seasonal Heat Storage

Zeolite 13X molecular sieve with high sorption capacity and significant sorption rate has been considered a promising candidate for seasonal heat storage. In this study, a code is developed to simulate the adsorption process between zeolite and water in all ranges of partial pressures, temperatures, and sorbate loadings. The results from the proposed code were compared with experiments and good agreement was observed. After validation, the developed model was used to study the effective parameters involved in the adsorption process of binder-free Zeolite 13X. A parametric study considering various temperatures and water content in the inflow air was conducted and the influence of different factors on the outlet temperature and adsorption enthalpy has been studied. This parametric study gives a good insight into the measures which can be taken for achieving the desired released energy or having the outlet temperature in the preferred range. The simulations have been conducted in a variety of temperature ranges provided during the desorption process, the humidity amount, and the mass flow rate of the incoming air. The relative influence of each parameter in the specified ranges is presented. The results have demonstrated the direct relationship of the partial pressure of water vapor and the desorption temperature with the adsorbed water amount and adsorption enthalpy while changing the mass flow rate mostly influences the discharging time.

Wind tunnel test and numerical study of a multi-sided wind tower with horizontal heat pipes

Passive ventilation such as wind towers can ventilate spaces by using regional pressure differences and the stack effect. Wind towers are often closed throughout the winter to prevent an increase in heating energy demand. Heat pipes can be installed to transfer heat from the outgoing to the incoming air, however the inclusion of heat recovery can incur a pressure drop that negatively impacts ventilation rates. Here it is shown that with an array of horizontally arranged heat pipes, ventilation rates of 0.1 m3/s are maintained at a 1 m/s inlet velocity. The incoming air temperature was raised by up to 2.8 °C, thereby increasing the operational window of the passive ventilation system. By mounting the heat pipes horizontally through the wind tower, direct heat transfer is facilitated between the inlet and outlet. The results demonstrate how a passive ventilation and heat recovery system is likely to operate in the winter months of a cooler climate according to the wind speed and temperature difference between the fresh and exhaust air. It is intended that this system will be further developed to provide both heating and cooling in the winter and summer respectively by installing a seasonal thermal loop.

Measurement of Instantaneous Mass Flow Rate of Polypropylene Gasification Products in Airflow

A simple semi-empirical gas-dynamic approach for measuring the instantaneous mass flow rate of gasification products of low-melting solid material (polypropylene) in a flow-through gas generator with ambient-temperature air as gasifying agent is proposed. The approach is validated experimentally in the direct-connect facility allowing for the short-term (~0.5 s) heating of incoming air up to ~1700 K by hydrogen injection and ignition or by pyrotechnic charge activation. The application of the proposed method for processing experimental data for 9 (of over 100) selected typical test fires showed that the time-averaged total yield of polypropylene gasification products varied from 43 to 120 g/s, while the air-to-gasification product mass ratio was 2.3–2.9. The results of all conducted experiments confirm the applicability of the proposed approach for determining the mass flow rate of gasification products. The universality of the proposed approach is confirmed by applying two different schemes of gas generator: one with hydrogen ignition and another with pyro-charge ignition.

Measurements of Some Meteorological Variables at a Tropical Location in Nigeria

This study observed six meteorological variables at a tropical location from 2016 to 2019. The measurement was performed at the meteorological station (7.55 0N; 4.56 0E) of Obafemi Awolowo University, Ile-Ife, Nigeria. The variables that were measured are: incoming solar radiation, net radiation, air temperature, surface temperature, relative humidity and wind speed. The results obtained showed that the maximum daytime monthly mean values of the incoming solar radiation (S) and net radiation (Rn) were recorded in March (782.0 and 545.4 Wm-2, respectively), which is the transition month from dry to wet season. The minimum daytime monthly mean values of S and Rn were recorded in August (443.9 and 330.4 Wm-2, respectively) which is the cloudiest month of the year at the study location. The daily air and surface temperatures (Ta and Ts, respectively) varied between 16.4 and 37.8 0C; 17.7 and 49.7 0C, respectively. The daytime maximum values peaked at about 15:00 LT with the maximum monthly mean values recorded in February (36.3 and 47.7 0C, respectively) and the daytime minimum monthly mean values recorded in August (28.9 and 33.3 0C, respectively). The daily values of relative humidity (Rh) ranged between 29 % and 98 % with a mean value of 47 %. The diurnal trend of wind speed (u) recorded at the study location ranged between 0.48 ms-1 to 2.10 ms-1.

AN EFFECTIVE WAY TO CLEAN THE SUPPLY AIR ALONG THE HEIGHT OF BUILDINGS WITH THE HELP OF A VENTILATION SYSTEM VALVE

Statement of the problem. The most important task at present is to improve the quality of cleaning the incoming air into the premises from sources of atmospheric air pollution using an effective local ventilation system with air purification. The introduction into design practice of effective methods of air purification in forced ventilation valves along the height of the building requires the development of scientifically sound methods of their calculations and design for buildings in conditions of high pollution of the city atmosphere. Results. An effective method of cleaning the air from gaseous pollutants for the premises of buildings made it possible to obtain in the summer the cleaning efficiency: for carbon (II) oxide - 93.75%; for aliphatic hydrocarbons - 80.59%, for phenol - 79.84%, for formaldehyde - 71.88%. In winter: for carbon (II) oxide - 95%, for aliphatic hydrocarbons - 84.78%; for phenol - 80.84%, for formaldehyde - 75.89%. Conclusions. The results of the study allow us to conclude about the effectiveness of using the developed method of cleaning the incoming air into the room using the developed valve of the ventilation system to the maximum permissible concentrations of gaseous pollutants in the room.