Longitudinal Air Research Articles

Mechanism and experimental study of arc suppression by polyphase longitudinal airflow

An arc extinguishing lightning protection device with a multi-arc extinguishing chamber structure has been gradually applied to the overhead line lightning protection, but the process and key factors of the arc building of the internal multi-phase flow suppression arc still need to be studied. In this paper, based on the theory of arc magnetohydrodynamics and Euler’s high velocity flow field model, a simplified model of arc coupled polyphase longitudinal air flow in a multi-pipe structure is established, the approximate solution of the model is made, and the development process of polyphase air flow and the extinction mechanism of the arc are obtained. At the same time, the arc quenching process of polyphase longitudinal air flow is also studied experimentally. The experimental results show that the continuous arc of power frequency can be stopped quickly and will not be reignited under the condition of polyphase air flow.

Numerical Simulations on the Extinguishing Effect of Water Mist System with Different Parameters of Longitudinal Ventilation in Curve Tunnel Fire

Once a fire occurs in a long curve tunnel, the mixing of hot smoke flow and cold air leads to turbulence due to the curvature’s impact. This phenomenon results in a greater thermal pressure difference at the fire source and a substantially greater temperature field than in the straight tunnel. The longitudinal air flowing along the wall loses a lot of velocity in the curve tunnel due to the massive wall friction. Under the same fire extinguishing conditions, the curve tunnel and straight tunnel have different requirements for longitudinal ventilation. Factors such as tunnel curvature, longitudinal ventilation operation time, and ventilation velocity were all evaluated in order to investigate the influence of longitudinal ventilation parameters on the fire extinguishing effect of water mist in the curve tunnel. The fire extinguishing effect of water mist coupling with longitudinal ventilation in the curve tunnel is studied by numerical simulation, and the recommended values of ventilation operation time and ventilation velocity in the curve tunnel with the participation of the water mist system are given. The results show that (1) the fire extinguishing effect of water mist decreases with the increase of curvature under longitudinal ventilation and (2) fire prevention effect is best when water mist and longitudinal ventilation are used in the curved tunnel, and the ventilation velocity should be greater than 2 m/s.

Preparation of long-lasting electret fiber felt by centrifugal air-assisted spinning process and electret post-treatment

The electret ultra-fine fiber filter material is prepared by the centrifugal airflow-assisted process. Moreover, the material can be used in the field of air filtration. A longitudinal air pressure draft sprinkler and a refined centrifugal spinning jet were designed to improve the fiber quality. According to different process parameters, in order to optimize the process of preparing ultra-fine fiber by centrifugal spinning, including the mass fraction of SiO2 (0%, 0.5%, 1%, and 1.5%), the effect of draft pressure (0, 0.05, and 0.15 MPa) on the diameter and morphology of the fiber was investigated. In addition, the effect of air pressure on the diameter and morphology of the fiber was investigated. The effects of key process parameters within the range of common production parameters on fiber quality and fiber morphology were expounded. For the prepared fiber felt, a preliminary test of the physical properties related to the molecular structure and filtration performance of the material was carried out, including the FTIR test and surface contact angle test of the material. After that, we carried out electret treatment of the ultra-fine fiber felt prepared by the centrifugal airflow-assisted process. Besides, we compared the surface electric potential and stability of the fiber felt by the needle electret process and wire electret process, respectively. Finally, the key physical properties of the filter media were tested. In addition, the filtration efficiency and resistance indices of the fiber felt prepared with different parameters were compared. Moreover, the effects of fiber morphology and the electret process on the performance of the filter felt were obtained. The study can provide new ideas and references for the preparation of electret ultra-fine fiber filter media.

Field testing and numerical modelling of fog production and control in the construction of mountain tunnels

Fog frequently appears in the portal area of mountain tunnels under construction in cold seasons because of the vast air temperature and air humidity differences between the inside and the outside of the tunnel. It consequently reduces visibility and causes accidents in the construction of mountain tunnels. In this study, field test on air temperature, air relative humidity, wall temperature and air velocity was initially performed in an inclined shaft of a mountain tunnel under construction in a typical winter day. The atmospheric temperature was −2 °C and fog was observed within the range of 550 m from the portal in the shaft. The test results show that the longitudinal air and wall temperatures have a linear increase, and the lowest air and wall temperatures are 16.8 °C and 14.9 °C at the portal, respectively. Furthermore, fog disappears when the air relative humidity is lower than 99% in the inclined shaft. Next, a computational fluid dynamics (CFD) model, solving the species transport and energy models, was established to reproduce the test. The comparison of the air temperature shows a good agreement. The fog lengths in the inclined shaft are 550 m for the test and 600 m for the simulation. This CFD model was then employed to study the effects of the inflow air relative humidity and the wall temperature on fog production and distribution in the inclined shaft. The results show that fog is produced when the inflow air relative humidity is above 86.6%, and the fog length increases significantly with the increase of the inflow air relative humidity. Additionally, the fog length also increases with the decrease of the wall temperature when the wall temperature at the portal is lower than 16.9 °C. An insulation layer imposed on the wall is accordingly proposed and its length is suggested over 50 m longer than the fog length to prevent fog production.

Influence of pool width on pioneering flame height of flame spread over jet fuel inside a bench-scale air flow tunnel

The development of liquid fire depends mainly on fuel evaporation and heat feedback of flame configuration which are both influenced by the ambient winds. In current work, the height of pioneering flame in the process of flame spread above the surface of jet fuel is measured inside a bench-scale air flow tunnel. The longitudinal air flow velocities are 0.45, 0.88, 1.3, 1.73, 2.15 and 2.57 m/s for both concurrent and opposed flame spreads. Five oil pans with the same length of 100 cm but different widths of 4, 8, 12, 16 and 20 cm are utilized. The experimental results of flame heights considerably deviate from the calculations of classic Thomas model and Oka et al. model. Then, the new-proposed non-dimensional parameter, characteristic size ratio of pool λ=d/D is introduced into Thomas’ model and Oka et al.’s model respectively. The measured flame heights follow well with the improved models H/d=aṁ*η(u∗)bλc and H/d=αFr2/3Q̇∗βλγ, regardless of direction of air flow. The values of empirical coefficients and exponents of the correlations a, b, c, η in improved Thomas model and α, β and γ in improved Oka et al. model are derived from the experimental results.

Experimental study of temperature profile and gas-liquid heat transfer in flame spread over jet fuel under longitudinal air flow

The rectangular pools with the same length of 100 cm but different widths of 4 and 20 cm are used to conduct experiments of flame spread over jet fuel of RP-3. The direction of longitudinal air flow is same and opposite to direction of flame spread respectively. Six air flow velocities 0.45, 0.88, 1.3, 1.73, 2.15 and 2.57 m/s are employed. The spatial temperature distributions and convective heat dissipation at pool bottom are examined using thermocouples. The heat loss is negligible for 10 mm-thick fuel layer, but it is evident for 3 mm-thick fuel layer. The integral method is proposed to calculate the flame radiation imposed to subsurface flow region. The gas-liquid heat transfer model including liquid-phase convection, flame radiation and convective heat dissipation is established for calculating energy balance involving flame spread over RP-3. The calculated heat fluxes follow well with experimental measurements, regardless of direction and magnitude of air flow. The current findings possess potential application and practical guidelines for fire prevention of liquid fires under longitudinal air flows. In order to restrict flame spread, it is a feasible method to cut off liquid convection or shield flame radiation.

Modeling the spatio-temporal dynamics of air pollution index based on spatial Markov chain model.

An environmental problem which is of concern across the globe nowadays is air pollution. The extent of air pollution is often studied based on data on the observed level of air pollution. Although the analysis of air pollution data that is available in the literature is numerous, studies on the dynamics of air pollution with the allowance for spatial interaction effects through the use of the Markov chain model are very limited. Accordingly, this study aims to explore the potential impact of spatial dependence over time and space on the distribution of air pollution based on the spatial Markov chain (SMC) model using the longitudinal air pollution index (API) data. This SMC model is pertinent to be applied since the daily data of API from 2012 to 2014 that have been gathered from 37 different air quality stations in Peninsular Malaysia is found to exhibit the property of spatial autocorrelation. Based on the spatial transition probability matrices found from the SMC model, specific characteristics of air pollution are studied in the regional context. These characteristics are the long-run proportion and the mean first passage time for each state of air pollution. It is found that the probability for a particular station's state to remain good is 0.814 if its neighbors are in a good state of air pollution and 0.7082 if its neighbors are in a moderate state. For a particular station having neighbors in a good state of air pollution, the proportion of time for it to continue being in a good state is 0.6. This proportion reduces to 0.4, 0.01, and 0 for the cell of moderate, unhealthy, and very unhealthy states, respectively. In addition, there exists a significant spatial dependence of API, indicating that air pollution for a particular station is dependent on the states of the neighboring stations.

Numerical investigation of the flow characteristics around two tandem propane fires in a windy environment

Investigation of wind-blown fires is highly applicable to fire safety of scenarios associated with burning industrial fuel tanks in wind and wildland fires. This paper conducts a numerical study on the flow characteristics around two propane fire sources in the tandem arrangement under cross wind. The heat release rate, cross wind velocity and fuel source spacing were changed. The results showed that in still air, as the fuel source spacing increases, the flame interaction gradually weakens. The corresponding shapes of flow velocity vector field experience three stages: a whole circular shape, two interacting circular shapes, and two separate circular shapes. As for the wind conditions, in the span wise direction, due to the impact of Rayleigh-Taylor instability, the counter-rotating vortex pair can be generated at the downstream of the fire sources. Under the influences of the counter-rotating vortex pair and blockage effect, a wake regime through flow entrainment is formed, which can reduce the longitudinal air flow velocity along the downstream centerline of fire sources. In the vertical direction, under the impact of fire-wind enhancement, the local flow velocity there can exceed free stream velocity. When the velocity is relatively small, there will be a reverse flow region around the downstream fire source. In addition, the blockage effect shows a non-monotonous trend with the increase of wind velocity.

Features of Glow Discharge burning between a hollow cathode and a mesh anode

The article is devoted to an experimental study of the features of the combustion of a glow discharge between a hollow copper cathode and a mesh anode in a longitudinal air flow. The cylindrical channel of the discharge chamber was formed by five glass sections separated by copper plates, which served as probes for measuring the plasma potential. Air flowed through the hollow cathode into a cylindrical channel. The anode was a metal grid of a copper plate 1.5 mm thick with holes uniformly located on it with a diameter of 1 mm. The distance between the hollow cathode and the mesh anode was 6.5 cm. Air pressure P, its velocity V, discharge current I and its voltage U varied respectively in the ranges: P = (6. 4 - 19) kPa, V = (0 - 10) m / s, I = (5-100) mA, U = (1. 0 – 2. 0) kV. The current-voltage characteristic had a negative differential resistance. By changing the ballast resistance, the forward and reverse branches of the current-voltage characteristic were removed. It was found that in the range of discharge currents I = (40-80) mA, these branches do not coincide, that is, hysteresis phenomena were observed. In the ascending branch of the current-voltage characteristic in the region of the current strength I = 80 mA, the discharge voltage increases sharply from U = 1. 2 kV to U = 1.6 kV. In this case, the discharge glow becomes more intense, wider and brighter, and the structure of light and dark zones along the discharge chamber also changes. Characteristic photos of the discharge are given. The formation of luminous and dark gaps inside the positive column of the discharge and their movement towards the anode was detected.

Impacts of longitudinal air velocity and fuel flow rate on flame radiative fraction in tunnel

Fires in tunnels have attracted special attention in recent years due to catastrophic fires, which cause huge human and economic losses. For accurate fire modelling and ventilation system design, it is critical to understand the correct radiative fraction (Xr) of the flame. Recent study has proved that Xr decreases with the increase of longitudinal air velocity in heptane pool fires. However, the impacts of longitudinal air velocity and fuel flow rate on Xr in propane or liquefied petroleum gas tunnel fires have not been studied. To fill the gap, this paper conducts two sets of fire experiments in a 1/20 reduced-scale wind tunnel using a porous burner. Unique visible flame shapes are observed and described by the ‘back-to-back conical frustum’. The geometric parameters and their variations with the momentum flux ratio are discussed. In comparison with the experimental results, the radiation model using the proposed flame shape shows an 80 % accuracy. The predictive radiative fractions of the two tests are calculated and compared with other tests from literature. The coupling effects of longitudinal air velocity and fuel flow rate on the flame radiative fraction are studied in detail. And their influences on key parameters of smoke extraction system are analyzed.

Experimental study and theoretical analysis on influencing factors of burning rate of methanol pool fire

A series of experiments were conducted to study the variation law of burning rate of methanol pool fire under natural ventilation and mechanical ventilation. Several factors are considered: size of pan, initial temperature of pan, air flow speed and so on. Also the heat transfer mechanisms of methanol pool fire are analyzed in-depth. The results show that: under natural ventilation, heat transfer from pan to pool by convection plays a significant role on the increase of burning rate. The higher the hydraulic diameter is, the lower the burning rate is. The higher the initial temperature is, the higher the burning rate is under initial development stage and steady burning stage. Under mechanical ventilation, the burning rate of methanol pool decreases followed by increase with the increase of longitudinal air flow speed. The air flow speed at inflection point of burning rate increases gradually with the increase of the characteristic length of pan. The Richardson number for different pans at the infection point of burning rate should be constant, the critical value is about 1 in this research.

Secondhand smoke exposure in public and private high-rise multiunit housing serving low-income residents in New York City prior to federal smoking ban in public housing, 2018

BackgroundTobacco remains the leading cause of preventable death in the United States, with 41,000 deaths attributable to secondhand smoke (SHS) exposure. On July 30, 2018, the U.S. Department of Housing and Urban Development passed a rule requiring public housing authorities to implement smoke-free housing (SFH) policies. ObjectivesPrior to SFH policy implementation, we measured self-reported and objective SHS incursions in a purposeful sample of 21 high-rise buildings (>15 floors) in New York City (NYC): 10 public housing and 11 private sector buildings where most residents receive federal housing subsidies (herein ‘Section 8’ buildings). MethodsWe conducted a baseline telephone survey targeting all residents living on the 3rd floor or higher of selected buildings: NYC Housing Authority (NYCHA) residents were surveyed in April-July 2018 (n = 559), and residents in ‘Section 8’ buildings in August-November 2018 (n = 471). We invited non-smoking household participants to enroll into a longitudinal air monitoring study to track SHS exposure using: (1) nicotine concentration from passive, bisulfate-coated nicotine filters and (2) particulate matter (PM2.5) from low-cost particle monitors. SHS was measured for 7-days in non-smoking households (NYCHA n = 157, Section 8 n = 118 households) and in building common areas (n = 91 hallways and stairwells). ResultsSmoking prevalence among residents in the 21 buildings was 15.5%. Two-thirds of residents reported seeing people smoke in common areas in the past year (67%) and 60% reported smelling smoke in their apartments coming from elsewhere. Most stairwells (88%) and hallways (74%) had detectable nicotine levels, but nicotine was detected in only 9.9% of non-smoking apartments. Substantial variation in nicotine and PM2.5 was observed between and within buildings; on average nicotine concentrations were higher in NYCHA apartments and hallways than in Section 8 buildings (p < 0.05), and NYCHA residents reported seeing smokers in common areas more frequently. ConclusionsSFH policies may help in successfully reducing SHS exposure in public housing, but widespread pre-policy incursions suggest achieving SFH will be challenging.

A longitudinal air–water trans-media dynamic model for slender vehicles under low-speed condition

A trans-media aerial underwater vehicle (TMAUV) could break through the single-medium limitation with the abilities to fly in the air, navigate underwater, and cross the air–water surface repeatedly. This paper researches on the air–water trans-media trajectory, including the water entry and exit trajectories, for slender TMAUVs. A longitudinal dynamic model is developed for the air–water trans-media process under low-speed condition. In this condition, the vehicle is assumed to be fully wetted and the water surface is assumed to be kept flat. A novel estimation for the fluid force is proposed for the immersed part of the vehicle, with angular velocity and angle of attack taken into consideration. Added mass and its derivatives are calculated by the cross-sectional method based on the slender body theory. To verify the feasibility and effectiveness of the model, water entry experiments of a slender projectile with a length of 2000 mm are performed with ground and underwater high-speed cameras. Simulations and experimental results show similar trends, as indicated by the comparisons. Furthermore, the proposed model is compared with computational fluid dynamics method simulating water entry and exit processes. Simulation results present good agreement with experimental results. On the basis of the results, the proposed model could be used to predict the water entry and exit trajectories with different initial conditions.

Experimental study of transient processes in a Glow Discharge

The article experimentally investigated the features of a glow discharge with a hollow cathode in a longitudinal air flow. The discharge chamber consisted of glass sections separated by copper plates serving as probes. The channel formed by such sections and probes had a cylindrical shape. Air flowed through the hollow cathode into the cylindrical channel. The anode served as a metal grid. Probes and electrodes were made of copper. The distance between the electrodes was 6.5 cm. The air pressure P, its speed V, the discharge current I and its voltage U changed respectively in the ranges: P = (6, 4 - 19) kPa, V = (0 - 10) m / c, I = (5-100) mA, U = (1, 0 - 2, 2, 0) kV. Volt-ampere characteristic had negative differential resistance. It was found that in the range of discharge currents I = (40-80) mA, the forward and reverse branches of the current-voltage characteristics do not match. When the current decreases (reverse branch), the discharge voltage rises sharply. This is due to the process of transition of a glow discharge into its non-stationary form, which was observed visually and was recorded photographically for all the characteristic modes of discharge. It was also shown that the flow of air allows a reverse transition to the usual form of discharge.

A protocol for measuring the impact of a smoke-free housing policy on indoor tobacco smoke exposure

BackgroundTobacco remains a leading cause of preventable death in the U.S., responsible for more than 440,000 deaths each year. Approximately 10% of these deaths are attributable to exposure of non-smokers to secondhand smoke (SHS). Residents living in public multi-unit housing (MUH) are at excess risk for SHS exposure compared to the general population. On November 30, 2016, the U.S. Department of Housing and Urban Development (HUD) passed a rule requiring all public housing agencies to implement smoke-free housing (SFH) policies in their housing developments by July 30, 2018.MethodsAs part of a larger natural experiment study, we designed a protocol to evaluate indoor SHS levels before and after policy implementation through collection of repeat indoor air samples in non-smoking apartments and common areas of select high-rise NYCHA buildings subject to the HUD SFH rule, and also from socio-demographically matched private-sector high-rise control buildings not subject to the rule. A baseline telephone survey was conducted in all selected buildings to facilitate rapid recruitment into the longitudinal study and assess smoking prevalence, behaviors, and attitudes regarding the SFH policy prior to implementation. Data collection began in early 2018 and will continue through 2021.DiscussionThe baseline survey was completed by 559 NYCHA residents and 471 comparison building residents (response rates, 35, and 32%, respectively). Smoking prevalence was comparable between study arms (15.7% among NYCHA residents and 15.2% among comparison residents). The majority of residents reported supporting a building-wide smoke-free policy (63.0 and 59.9%, respectively). We enrolled 157 NYCHA and 118 comparison non-smoking households into the longitudinal air monitoring study and performed air monitoring in common areas. Follow up surveys and air monitoring in participant households occur every 6 months for 2.5 years. Capitalizing on the opportunity of this federal policy rollout, the large and diverse public housing population in NYC, and robust municipal data sources, this study offers a unique opportunity to evaluate the policy’s direct impacts on SHS exposure. Methods in this protocol can inform similar SFH policy evaluations elsewhere.

Investigating the influence of diffractive interactions on ultrahigh-energy extensive air showers

The understanding of the basic properties of the ultrahigh-energy extensive air showers is dependent on the description of hadronic interactions in an energy range beyond that probed by the LHC. One of the uncertainties present in the modeling of air showers is the treatment of diffractive interactions, which are dominated by nonperturbative physics and usually described by phenomenological models. These interactions are expected to affect the development of the air showers, since they provide a way of transporting substantial amounts of energy deep in the atmosphere, modifying the global characteristics of the shower profile. In this paper, we investigate the impact of diffractive interactions in the observables that can be measured in hadronic collisions at high energies and ultrahigh-energy cosmic ray interactions. We consider three distinct phenomenological models for the treatment of diffractive physics and estimate the influence of these interactions on the elasticity, number of secondaries, longitudinal air shower profiles and muon densities for proton-air and iron-air collisions at different primary energies. Our results demonstrate that even for the most recent models, diffractive events have a non-negligible effect on the observables and that the distinct approaches for these interactions, present in the phenomenological models, still are an important source of theoretical uncertainty for the description of the extensive air showers.

Numerical investigation of PCM solidification in a finned rectangular heat exchanger including natural convection

The thermal energy storage got a significant role in the solar energy conservation to expand its use over time. To exploit solar energy continuously, we require a storage energy system. Phase Change Material (PCM) used in this kind of systems in order to store a great amount of thermal energy. This work concerns the solidification in the presence of the natural convection of a rectangular phase change material exposed to a cold airflow along the conducting sidewalls. With this intention, the first stage includes the presentation of a numerical model based on the conservation equations, treated by finite volume method. This numerical approach aims to follow the evolution of the various parameters characterizing the phenomenon of phase change (liquid-solid interface and solid fraction) during all the processes of solidification as well as the temperature and the velocity distribution in the PCM storage systems. Moreover, this study presents the transient evolution of the longitudinal air temperature profiles. It also presents the effect of fins number on heat transfer enhancement and the temporal evolution of the solidification front. The advantage of this study is to find a solution to extract the maximum of heat during the solidification of the PCM. This solution is to take into account the natural convection and also the addition of the fins.

Optimization of Geometric Parameters of Longitudinal-Connected Air Suspension Based on a Double-Loop Multi-Objective Particle Swarm Optimization Algorithm

Longitudinal-connected air suspension has been proven to have desirable dynamic load-sharing performances for multi-axle heavy vehicles. However, optimization approaches towards the improvement of comprehensive vehicle performance through the geometric design of longitudinal-connected air suspension have been considerably lacking. To address this, based on a 5-degrees-of-freedom nonlinear model of a three-axle semi-trailer with longitudinal air suspension, taking the changes of driving conditions (road roughness, speed, and load) into account, a height control strategy of the longitudinal-connected air suspension was proposed. Then, in view of the height of the air spring under various driving conditions, the support vector regression method was employed to fit the relationship models between the performance indices and the driving conditions, as well as the suspension geometric parameters (inside diameters of the air line and the connectors). Finally, to tackle the uncertainties of driving conditions in the optimization of suspension geometric parameters, a double-loop multi-objective particle swarm optimization algorithm (DL-MOPSO) was put forward based on the interval uncertainty theory. The simulation results indicate that compared with the longitudinal-connected air suspension using two traditional geometric parameters, the optimization ratios for dynamic load sharing coefficient and root-mean-square acceleration at various spring heights are between −1.04% and 20.75%, and 1.44% and 35.1%, respectively. Therefore, based on the signals measured from the suspension height sensors, through integrated control of inflation/deflation valves of air suspensions, as well as the valves’ inside connectors and air lines, the proposed DL-MOPSO algorithm can improve the comprehensive driving performance of the longitudinal-connected three-axle semi-trailer effectively, and in response to changes in driving conditions.

Flame extension lengths beneath a confined ceiling induced by fire in a channel with longitudinal air flow

This paper investigates the length of flame extension for an impinging flame underneath the confined ceiling in a channel with longitudinal air flow. Previous works in this field have been primarily concerned with un-confined ceilings and no forced air flow conditions. Under longitudinal air flow conditions, the flame extension beneath the channel ceiling is non-symmetrical, that is, different in the upstream and downstream directions from the fire source. In this study, experiments were carried out with two channeled ceilings with widths of 1.5 m and 0.5 m. Square porous gas burners of different sizes were employed as the fire source, using propane as fuel, with various heat release rates and source-ceiling heights. The flame extension lengths beneath the ceiling, both upstream and downstream from the fire source, were measured. Their difference as well as their total length was quantified for different magnitudes of forced longitudinal air flow along the channel. Results show that the flame extension lengths beneath the ceiling increases with heat release rate, but decreases with source-ceiling height, channel width, burner size or longitudinal air flow speed. With a longitudinal air flow, the flame extension is longer downstream than upstream. Non-dimensional correlations are proposed for the flame extension lengths (upstream, downstream and their total length), based on the unburnt fuel distribution upstream and downstream, as well as considering air entrainment of the ceiling flow, which further consumes the unburnt fuel along the ceiling. These correlations are shown to fit the data well.

Investigation the effect of outdoor air infiltration on the heat-shielding characteristics the outer walls of high-rise buildings

The presented article considers the influence of infiltrated outdoor air on the heat-shielding characteristics of the exterior walls of modern residential and public buildings. A review of the sources devoted to this problem confirmed its relevance at the present time, especially for high-rise buildings. The authors of the article analyzed the effect of longitudinal and transverse air infiltration on the heat-shielding characteristics of the outer wall of a 25-story building that was built in Samara. The results showed a significant reduction of the reduced resistance to the heat transfer of the outer wall when air is infiltrated through it. There are the results of full-scale examination of external walls to confirm the calculated data. Based on the results of the study carried out by the authors of the article, general recommendations on the internal finishing of the outer walls of high-rise buildings are given.