Abstract In the bourbon industry, rickhouses store bourbon barrels undergoing the maturation process. Ambient conditions—including temperature, relative humidity, and overall air composition—play a critical role in the maturation process of bourbon within rickhouses. The presence of ethyl alcohol vapors is a byproduct of the aging process and has been a long-standing issue within the industry. Exposure to ethanol vapor can hasten the corrosion of barrel hoops, potentially compromise the integrity of the barrels and lead to product loss. Newly constructed rick-houses have been designed to mitigate the vapors with natural ventilation from windows and air vents. This study shows that natural ventilation does not really allow air to move through the stacks, even in an empty rickhouse. The evaluation was performed using differential pressure measurements and smoke tracing to characterize extremely low-energy airflow. Differential pressure measurements and smoke tracing conducted on the first floor and crawl space of a newly constructed empty rickhouse indicated that while air enters the warehouse through windows and vents, it does not effectively penetrate the interior rick structures. Airflow is largely confined to the crawl space and walkways, with limited movement into the central rick areas, indicating that natural ventilation alone may be insufficient for comprehensive air circulation. The findings provide important insights into airflow behavior and its implications for the spirits industry, while contributing to a growing body of evidence suggesting that natural ventilation alone may be insufficient to adequately mitigate a known de-passivating agent, ethyl alcohol vapor, accumulation in current rickhouse designs. The results align with the United Nations Sustainable Development Goals of “Sustainable Cities and Communities” (SDG 11) and “Responsible Consumption and Production” (SDG 12). Improved understanding of airflow characteristics may support the development of better-ventilated rickhouses, enhancing sustainable production practices and reducing the impact of material and product losses on surrounding communities. 1. Introduction One of the final stages of bourbon whiskey production is the maturation process. For this process to occur, barrels of bourbon are stored in warehouses known as rickhouses. Each building comprises several levels or ricks [ 1]. Typically, the buildings are composed of three to four levels, made of wood, and can store up to 20,000 barrels. Modern rickhouse designs have expanded and become highly engineered, often accommodating six to seven ricks. These design modernizations have increased the total storage capacity in Kentucky to over 10.5 million barrels [ 2]. Numerous environmental, branding, and other factors have impacted the design of bourbon storage facilities over the years. Distilleries consider the maturation process one of the most important factors in bourbon production. The temperature, humidity, and air quality are a few climate factors that impact the maturation process [ 3]. The state of the art in ventilating bourbon rickhouses has evolved from passive, natural airflow systems to more deliberate, controlled strategies aimed at enhancing aging consistency and product quality. Traditionally, rickhouses rely on open windows, slatted walls, and seasonal temperature variations to drive natural ventilation, which contributes to the unique flavor profiles of bourbon by promoting barrel interaction with the environment. For example, temperatures inside a rickhouse can differ significantly, with variations of up to 8.5 °C (15 °F) between floors. The upper levels tend to be hotter and drier, leading to greater water evaporation and raising the alcohol percentage by volume (ABV), sometimes reaching 70% or higher. In contrast, the lower floors are cooler and more humid, where alcohol evaporates more readily, resulting in a lower ABV. Very few distilleries control the climate in rickhouses, instead relying on natural ventilation. The configuration, number, and distribution of windows are key factors in regulating airflow and temperature fluctuations within the warehouse [ 1]. A few experimental designs have implemented crawl spaces and air vents to improve airflow. The weather has a huge impact on the maturation process. Expansion of the barrels in warmer temperatures causes the pores in the oak wood to dilate, allowing the alcohol inside to seep into them and absorb tannins from the wood barrel, thus adding flavor. The dilated pores also raise the probability for the alcohol inside to evaporate. During the winter, pores contract, forcing the alcohol along with the absorbed tannins out of the pores. Barrels along the top of the rickhouses and nearest the walls are exposed to the greatest temperature variation. Therefore, these barrels will absorb more flavor than the interior barrels [ 4]. Though high variation is beneficial to bourbon, consistent extreme temperatures have a negative effect on bourbon, with high heat causing excessive evaporation over time, and severe cold restricting the movement of bourbon into the wood pores [ 5, 6]. Steel corrosion due to alcohol, particularly ethanol and methanol, is primarily driven by impurities like water, acetic acid, or chlorides rather than the pure alcohol itself. It causes localized pitting and stress-corrosion cracking in carbon and stainless steels. High alcohol concentrations, especially when water content is increased, dramatically reduce pitting potential and increase corrosion rates [ 7]. Ethanol is hygroscopic and can absorb water from the air, forming aqueous mixtures that may promote corrosion of metals such as carbon steel by facilitating electrochemical reactions [ 8]. Thus, evaporated ethyl alcohol vapor in the air, particularly in confined or poorly ventilated environments, poses a structural stability risk by accelerating metal corrosion. The bourbon barrels act as large heat sinks due to their mass, resulting in the barrels experiencing less temperature change than the ambient environment. This causes condensation to form on the barrels, allowing the evaporated ethyl alcohol vapor to mix with water in the hoops and accelerate corrosion. Figure 1 shows the severe corrosion of the metal bands or hoops on bourbon barrels. As the barrels expand under higher temperatures, increased outward pressure is exerted on the metal hoops. Severely corroded hoops may fail, leading to the expensive release of bourbon whiskey. When one barrel fails, a cascading effect can develop due to the volume of alcohol released, which increases the ethyl alcohol vapor content. This effect generates considerable costs for the industry. Corrosion is not limited to barrel hoops; sheet metal, structural steel, and other corrosion-prone materials can be affected. Since ethyl alcohol vapor is denser than air, higher concentrations tend to form on the lowest levels of the rickhouse, where more instances of iron hoop corrosion have been observed [ 9]. Ethyl alcohol vapor is hazardous due to its corrosiveness, flammability, and propensity for explosion. Under extreme conditions, prolonged accumulation of ethanol vapor can result in concentrations reaching the flammable or explosive range [ 9]. Over the past thirty years, numerous distillers have experienced rickhouse fires and structural collapses, losing hundreds of thousands of barrels. In 2019, a fire in a Jim Beam rickhouse destroyed 45 thousand whiskey barrels. Emergency crews attempted to prevent leakage into a nearby creek, but alcohol was detected more than twenty-three miles down-stream from the rickhouse where the creek met the Ohio River. In 2018, a Barton 1972 rick-house collapsed, causing thousands of barrels to spill into a tributary of the Beech Fork River [ 10]. Improved ventilation in a bourbon rickhouse directly enhances industry sustainability by reducing product loss and preserving aging assets. During maturation, a portion of the spirit evaporates, but poor airflow in the rickhouse can lead to localized vapor buildup and uneven temperature and humidity conditions, accelerating unnecessary losses. By highlighting the issue of poor ventilation and limited airflow, the industry can take the necessary steps to either improve air circulation or reduce the alcohol vapor in the rickhouse atmosphere. From an environmental and safety perspective, improved ventilation also helps limit the accumulation of alcohol vapors, which can contribute to the corrosion of metal components, particularly barrel hoops. This translates into less product loss, including the raw materials needed to produce bourbon and energy associated with the grain processing and for the maturation process, lower demand for raw materials such as oak, grain, corn, and steel, and reduced energy consumption associated with manufacturing new barrels and disposing of damaged or burst barrels. Proper ventilation supports a cleaner, safer, and more resource-efficient operation, aligning both economic performance and environmental stewardship in the spirits industry. The first step is for the industry to understand that change is needed and that modern tools can be used to design an efficient rickhouse. Airflow within the warehouse is primarily driven by natural fluctuations in temperature and humidity, as well as structural constraints. A thorough understanding of these airflow patterns is critical for characterizing current environmental conditions and forecasting the effects of proposed ventilation modifications. The authors have engaged extensively with industry professionals regarding concerns about barrel hoop corrosion attributed to warehouse climate. Multiple oral presentations have also been given at the Jim Beam Institute (JBI) conferences highlighting this issue. The JBI conferences are held annually at the University of Kentucky, with the inaugural conference in February 2020. Throughout the bourbon industry’s extensive history, the design and implementation of rickhouses have been passed on from generation to generation. However, the design process is highly speculative, and the effects of different building designs on bourbon maturation and the sustainability of the bourbon industry have not been studied. Schafrik et al. discussed a ventilation survey conducted in an empty rickhouse with a new design in central Kentucky [ 11]. The building had an unusual ground vent design, a cupola, and a specialized barrel storage system. These designs were implemented to mitigate the presence of corrosive ethyl alcohol. They observed that the rickhouse had pockets of high resistance and minimal airflow into the interior of the ricks. Recent advances have introduced more systematic approaches, including automated louvers, airflow modeling, and environmental monitoring systems that track humidity and temperature gradients throughout the structure. Some distilleries are exploring hybrid ventilation designs that maintain traditional character while improving control over aging conditions. Despite these developments, scientific literature on optimized rickhouse ventilation remains extremely limited, as much of the knowledge remains proprietary or anecdotal within the industry. One novel rickhouse design incorporates a vented crawl space. The goal of this design is to have ethyl alcohol vapor drop and accumulate in the crawl space, thereby decreasing the vapor concentration around the barrels and reducing barrel corrosion. The air vents then enable airflow to remove ethyl alcohol vapor from the crawl space. Natural ventilation, by its nature, is dependent on ambient conditions and is very low-energy except during periods of high natural pressure or temperature (e.g., high winds or extremely high temperatures). As such, capturing the airflow data is extremely difficult, as will be shown later. Analysis of natural ventilation performance has been conducted using methods such as tracer gas decay and air motion measurement [ 12, 13]. Omrani et al. (2017) provide a review of evaluation tools for natural ventilation in buildings [ 14]. Smoke tracing can be used in these low-energy systems to characterize overall airflow patterns. Such visualization will provide movement patterns, but these movements cannot be quantified [ 15]. It should be noted that Computational Fluid Dynamics and other numerical methods may be capable of calculating the values and flow patterns in such complicated environments, but they should be calibrated to flow and/or pressure measurements in such environments. This work presents a methodology for evaluating airflow in rickhouses with vented crawl spaces that includes conducting both ventilation surveys and smoke tracing, which is the first step in establishing flow patterns. Conclusions are drawn from the results, and the implications for the industry are discussed. More specifically, the results of this research directly align with the United Nations Sustainable Development Goals (SDGs) “Sustainable Cities and Communities” (SDG 11) and “Responsible Consumption and Production” (SDG 12). Airflow measurements will help design better-ventilated rickhouses, resulting in sustainable production practices and ensuring that nearby communities are less impacted by wasted materials and products. 2. Materials and Methods There are a variety of methods that are used to measure and/or assess airflow in confined spaces, such as mine openings, tunnels, buildings, etc. Rickhouses are structures designed to store a large number of barrels and, therefore, restrict airflow to very low flow rates, making the capturing of data difficult. Differential pressure surveys and smoke surveys, discussed below, are methods used to assess and sometimes quantify airflow in low-flow-rate environments. 2.1. Differential Pressure Surveys Examples of such surveys, conducted with micromanometers, occur in industries such as desalination [ 18] and mining [ 19]. Ideal survey locations are dependent on the building layout. Best practice includes examining the perimeter to establish ingress and egress points and quantity estimates, examining the main corridors where higher flow may be expected, and performing representative surveys at points where the building layout is repetitive. 2.2. Smoke Surveys Characterizing airflow with a sheet laser and smoke has numerous applications and has been used in the mining industry [ 20, 21], fire detection [ 22, 23], and wind tunnels [ 24]. Smoke tracing is considered a diagnostic and visualization tool useful for identifying airflow direction, leaks, short-circuiting, and dead zones. It primarily shows airflow direction and general patterns, but it does not show precise values, and it cannot directly measure air velocity, flow rate, or pressure [ 25]. In addition, it is difficult to apply effectively in large sections (e.g., ventilation of underground mines), long airways, or full ventilation networks [ 26]. Temperature gradients, humidity, and density differences can alter smoke movement, sometimes masking stratification or giving misleading impressions of airflow paths [ 25]. In some cases, other reflective particles, such as dyes, can be used. Smoke is a more practical tracer medium than dyes, as it readily conforms to ambient airflow and enables indirect visualization of air movement [ 27, 28]. The smoke generator imparts momentum to the smoke. This means initially, the smoke does not conform to the airflow patterns. After a short time, when the smoke loses its initial momentum, it will then conform to the surrounding air-flow patterns. Should there be no prevailing airflow direction, the smoke will travel the distance initially given and then simply rise due to its lower density. The smoke itself can be visually traced; however, it can be hard to gain a detailed understanding of the airflow pattern. A sheet laser can be used with smoke to visualize the flow more clearly. The laser will reflect off the smoke particles, providing greater clarity in the flow visualization. 2.3. Case Study In July 2024, a ventilation survey was conducted in a newly constructed rickhouse by Whiskey House of Kentucky in Elizabethtown, Kentucky. The seven-story warehouse is shown in Figure 2 and can store approximately 40,000 barrels. Unique to this building style are the air vents at the base of the building, which lead into the crawl space. This architectural variation represents a departure from conventional designs and provides a unique opportunity to assess how base-level ventilation influences internal airflow distribution and vapor dispersion. This study builds upon prior research by examining the impact of this alternative warehouse configuration on natural ventilation efficacy and its potential role in mitigating ethyl alcohol vapor accumulation. The survey was conducted while the warehouse was still empty, which is a rare occasion, and differs from typical operating conditions, where the rickhouse remains filled for most of its service life. This approach was necessary to prevent contamination of bourbon barrels by oil residue from the smoke generator. The entire survey was conducted within a few hours during the night, and specifically between 9 p.m. and 1 a.m., on 12 July 2024. Table 1 presents the ambient temperature and wind velocity during the measurements, as retrieved from a local weather station that collects data hourly. There is no solar load to report as all tests were done after sunset. On the front and rear faces of the building, there are six air vents to the left of the entrance and ten air vents to the right ( Figure 3). Vents are placed less frequently on the side of the building. The intention of the design is to direct airflow through the length of the crawl space. The locations of the differential pressure measurements along the walkways are shown in Figure 7. Each point represents the measuring point, and the dashed line is the length of the tubing. Measurements were conducted along the walkways ( Figure 5) and alternated between approximately 6.1 and 12.2 m (20 and 40 ft) in length. These locations are represented by the shorter and longer pairs of measurement points in Figure 7. Because the rickhouse system is very complex, little would be attained by recording pressure differentials between distant locations. It is reasonable to assume that a pressure differential between two locations will result in airflow between them. As distance increases in a complex ventilation system, this assumption becomes less valid. The locations selected are not a limitation, but were chosen because airflow between the two points is conceivable and relevant to the ventilation of alcohol vapors away from the barrels. Results are given in Section 3.1. The micromanometer (DP-CALCTM micromanometer model 5815 by TSI ShoreView, MN, USA) has a listed accuracy of ±1.244 Pa [ 29]. Measurements within the accuracy range could not be statistically differentiated from zero and were considered non-significant. In such cases, a zero pressure difference was recorded. A smoke survey was then conducted after the pressure survey to visualize airflow. It should be noted that, because the differential pressure survey results were essentially identical across locations, they did not affect the selection of smoke release locations. Had the results shown spatial variation, this would have been taken into account. The smoke survey focused on potential airflow through the windows and crawl space vents into the building. The smoke survey was conducted at night to utilize the sheet laser without interference from daylight. Figure 5b displays the lighting conditions at the time of the survey. The initial set of tests was conducted in the west walkway between the windows and ricks. A sheet laser (Z20M18B-F-532-lp45 Z-LAZER GmbH, Freiburg, Germany) was set up horizontally and vertically to determine the flow patterns, while the smoke generator (Bullex SG4000, LION Group, Dayton, OH, USA) was placed outside the rickhouse to simulate outside air that may be flowing into the building. The generator can produce 630 m 3/min of smoke. The testing setup is shown in Figure 5a. In the first test, the smoke generator is placed next to the window (position A in Figure 5a), while in the second test, the smoke generator is placed next to the crawl space vent (position B in Figure 5a). The purpose of these two tests was to evaluate the airflow through the window and crawl space vent, respectively. 3. Results and Discussion 3.1. Differential Pressure Survey The measurements of the differential pressure survey are presented in Table 2, where the measurement location and the corresponding pressure differential in pascals are given. All measurements were within a range of 0 to 0.4 Pa. As these very low-pressure measurements fall within the tool’s error range, all readings were deemed insignificant. This means that by the standard method, no detectable airflow occurs within the rickhouse at these environmental conditions. Results from a pressure-differential survey in a different rickhouse style are reported by [ 11], who also found that airflow between the walkway and ricks is undetectable. After the pressure survey, it was determined that a smoke survey would provide a visualization of the low airflow, if any. 3.2. Smoke Survey A video recording captured the movements of the smoke through the sheet laser for each test. To present the smoke movement, frames were selected from the video that demonstrate the movement over time. Five frames were selected in intervals of five to fifteen seconds from the time the smoke crossed the laser plane to the end. Figure 9 shows five frames (plan view) from the window test and a reference frame with the window location and the approximate width of the walkway. The sheet laser was placed horizontally, parallel to the floor. Frame 1 displays the initial conditions; lingering smoke from previous tests was still in the environment. In Frame 2, the smoke is seen after it enters the walkway through the window. In Frame 3, the smoke begins to lose momentum, and in Frame 4, the smoke simply recirculates. Finally, in Frame 5, the smoke stagnates. The smoke is stagnating inside the walkway and is not infiltrating further into the ricks at the bottom of the photo. If airflow was infiltrating the ricks, it would be expected for the smoke to clear after some time as it continued into the building. Frames 1 and 5 show smoke after the test, indicating that airflow remains stuck in the walkway. The above clearly indicates that although the smoke enters the building with momentum (Frames 2 and 3), it quickly dissipates and becomes stagnant (Frames 4 and 5). A simplified vertical cross-section diagram of smoke movement in the window test is shown in Figure 10 (smoke movement is in red), where the smoke enters the window with the wind, recirculates in the walkway, and exits through one of the other walkway windows. A plan view is shown in Figure 11 (smoke movement is in red). The smoke movement in the air vent test is shown in Figure 12, where the blue indicates the smoke movement. The smoke enters the crawl space through the air vent, rises into the walkway, and then exits through the window. The walkway tests were also conducted on the 7th floor of the building. The frames of the 7th-floor test are shown in Figure 13. Smoke was released in the center of the walkway between the exterior wall with windows (left side of images) and rows of ricks (right side of images). A noticeable difference between this floor and the ground floor was the wind level. This was expected, as wind intensity against a building generally increases with elevation under normal conditions. Circulation within the walkway was faster, and air did not stagnate. However, like at the ground level, the smoke did not infiltrate the ricks. 3.3. General Airflow Patterns A simplified diagram of the airflow movement and zones of high air resistivity is shown in Figure 14. The results suggest that airflow in and out of the rickhouse is concentrated at the extremities of the building. The interior of the building is significantly more resistant to airflow, resulting in columns of mostly stagnant air. Air entering the building via the windows will recirculate and linger inside the walkway until it leaves via the same window, another window, or rises. Air from the outside does not reach the interior of the building through the windows. Air is likely rising through the walkways at their edge, where the ricks and walkways meet. There was more air movement in the 7th-level walkways, likely due to the higher wind speeds at that elevation. However, there was still no penetration into the ricks, just circulation in the walkway. The ricks provide a large source of mass to interrupt airflow, increasing air resistance. If the ricks were filled, the resistance to airflow is expected to increase. The central walkways are isolated and experience minimal airflow other than rising air. Airflow is rising through the ridge vent at the crown of the roof; however, air exfiltration out of the building is slow. The foundation vents provide airflow, with the larger foundation front vents providing better flow than the smaller foundation side vents. Air entering the crawl space below the outer walkways does not leave the basement except through the seams in the floor. Air moves through the foundation front vents, gets to the end of the walkway, and then begins to rise or leaves through a nearby window. 4. Conclusions The bourbon industry utilizes rickhouse-style warehouses for bourbon maturation, a key step in bourbon production. During the maturation process, alcohol vapor can accumulate in the lower levels of the warehouse. Evaporated ethyl alcohol vapor in the air can accelerate the corrosion of the barrel’s metal bands, which leads to product loss if the bands were to break. The industry relies on natural ventilation to control the amount of ethyl alcohol vapor in the air. A pressure differential survey and a smoke survey were conducted on the first floor and crawl space of a newly constructed rickhouse. The differential pressure measurements determined that the airflow throughout the building was undetectable, justifying the need for a smoke survey. The smoke used had a lower density than the surrounding air and would rise unless other forces were present. The smoke survey showed that air primarily enters and exits the rickhouse via the windows. Air from these entry points did not infiltrate further than the walkway or past the first concrete pier into the ricks. Additionally, airflow was present in the crawl space. Air flowing in through the foundation side vents did not flow deeper into the rickhouse. Air that enters through the larger foundation front vents penetrates under the first few ricks. Stagnant air within the ricks is assumed to lead to the accumulation of ethyl alcohol vapor. It should be noted that the rickhouse was empty of barrels at the time of testing. The addition of barrels would decrease the cross-sectional area of the flow area, increasing the resistance of the building as a whole and decreasing airflow into the ricks. Rickhouses with varying amounts of barrels are sought by the authors in future research. The results of this study can be used to verify the output of CFD models, reducing the need to unnecessarily expose the product to potential harm from the smoke used in this style of survey. Overall, this work presents a methodology for evaluating airflow in rickhouses with vented crawl spaces through the combined use of ventilation surveys and smoke tracing to establish airflow patterns. It contributes novel insight to an under-researched aspect of bourbon warehouse design by applying smoke tracing techniques—commonly used in mining and fire safety—to characterize extremely low-energy airflow within a modern rickhouse. The unique crawl-space ventilation system examined here differs significantly from previously studied warehouse configurations, yet the results corroborate earlier findings, indicating limited airflow penetration into the rick structures. The findings provide important insights into airflow behavior and its implications for the spirits industry and support a growing body of evidence that natural ventilation alone may be insufficient to mitigate ethyl alcohol vapor accumulation in current warehouse designs. Improved understanding of airflow characteristics can support the design of better-ventilated rickhouses, promoting more sustainable production practices while reducing the impact of wasted materials and product losses on surrounding communities. The outcomes of this research align closely with the United Nations SDG 11, related to reducing the environmental impact of bourbon maturation and storage operations, and SDG 12, related to reducing resource footprints and waste generation by 2030. The first step for such major interventions is the qualitative or quantitative identification of the root cause of the issue at hand. Future research should focus on establishing industry standards for airflow requirements throughout rickhouses, which currently do not exist. It should include an evaluation of the effect of wind and temperature variation on airflow patterns. In addition, a number of CFD models could be established to respond to rickhouse operational questions. Author Contributions Conceptualization, S.J.S.; Investigation, S.J.S., Z.E.W., M.W.L., and N.T.K.; Methodology, S.J.S. and M.W.L.; Project Administration, S.J.S.; Supervision, S.J.S.; Validation, S.J.S. and M.W.L.; Visualization, Z.E.W., M.W.L., and Z.A.; Writing—Original Draft, Z.E.W.; Writing—Review and Editing, S.J.S., Z.E.W., M.W.L., N.T.K., Z.A., and B.M.D. All authors have read and agreed to the published version of the manuscript. Funding CARERC partially supported this publication through student funding with Grant 6T42OH010278. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIOSH/CDC. Informed Consent Statement Not applicable. Data Availability Statement Data will be made available upon request. Acknowledgments This paper would not have been possible without the support of the Whiskey House of Kentucky, which allowed the authors access to their newly built rickhouse. 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( b) Picture of the western walkway of the rickhouse; three levels of ricks are shown on the right side of the picture. Dashed circles represent barrels. Figure 5. ( a) Cross-section A-A’. Barrel locations in the ricks are shown in dashed lines. ( b) Picture of the western walkway of the rickhouse; three levels of ricks are shown on the right side of the picture. Dashed circles represent barrels. Figure 6. View of an empty rick and walkways parallel and perpendicular to the rick. Figure 6. View of an empty rick and walkways parallel and perpendicular to the rick. Figure 7. Walkway differential pressure survey locations. All surveys were conducted at the walkway level. Dotted lines represent length of tubing between pressure differential measurement points. Figure 7. Walkway differential pressure survey locations. All surveys were conducted at the walkway level. Dotted lines represent length of tubing between pressure differential measurement points. Figure 8. Rickhouse interior differential pressure measurement locations. All surveys are conducted at the walkway level. Dotted lines represent length of tubing between pressure differential measurement points. Figure 8. Rickhouse interior differential pressure measurement locations. All surveys are conducted at the walkway level. Dotted lines represent length of tubing between pressure differential measurement points. Figure 9. Plan view of the window horizontal smoke test. The laser is placed on the walkway and the window is in the middle right of each frame, as shown in Frame 0. Figure 9. Plan view of the window horizontal smoke test. The laser is placed on the walkway and the window is in the middle right of each frame, as shown in Frame 0. Figure 10. Smoke movement through the window; smoke enters the walkway from the window and travels up or down the walkway (perpendicular to this cross-section). Dashed circles represent barrels. See Figure 4 for the location of the dashed line A-A’. Figure 10. Smoke movement through the window; smoke enters the walkway from the window and travels up or down the walkway (perpendicular to this cross-section). Dashed circles represent barrels. See Figure 4 for the location of the dashed line A-A’. Figure 11. Smoke movement between windows along a walkway; smoke enters the walkway from one of the windows, slowly travels along the walkway, and exits through a different window without interacting with the ricks (even though they are empty). Dashed lines represent barrels in plan view. Figure 11. Smoke movement between windows along a walkway; smoke enters the walkway from one of the windows, slowly travels along the walkway, and exits through a different window without interacting with the ricks (even though they are empty). Dashed lines represent barrels in plan view. Figure 12. Smoke movement through the foundation air vent; smoke enters through the foundation air vent and exits through the windows without moving through the ricks. Dashed circles represent barrels. See Figure 4 for the location of the dashed line A-A’. Figure 12. Smoke movement through the foundation air vent; smoke enters through the foundation air vent and exits through the windows without moving through the ricks. Dashed circles represent barrels. See Figure 4 for the location of the dashed line A-A’. Figure 13. Seventh-floor walkway smoke test. The red arrow shows the direction of smoke generation. Figure 13. Seventh-floor walkway smoke test. The red arrow shows the direction of smoke generation. Figure 14. Generalized Airflow Pattern. Dashed circles show local air recirculation patterns. Solid arrows show direction of air movement to the roof. Figure 14. Generalized Airflow Pattern. Dashed circles show local air recirculation patterns. Solid arrows show direction of air movement to the roof. Table 1. Ambient temperature and wind velocity during the measurement period. Table 1. Ambient temperature and wind velocity during the measurement period. Parameter/Time 9 p.m. 1 a.m. Comment Temperature 28 °C 23.3 °C Steady drop Wind Velocity 1.3 m/s 0 m/s Steady between 9 p.m. and midnight; dropped to 0 at midnight Table 2. Differential pressure measurements. Table 2. Differential pressure measurements. Location ΔP (Pa) Location ΔP (Pa) Location ΔP (Pa) Location ΔP (Pa) 1 −0.4 14 −0.2 27 −0.1 40 0 2 −0.1 15 −0.3 28 0 41 0.1 3 −0.1 16 −0.2 29 0.1 42 0 4 0 17 −0.1 30 0.1 43 0.1 5 −0.2 18 −0.1 31 0 44 −0.1 6 0 19 0 32 0 45 0.2 7 0.1 20 0.2 33 0.1 46 0.1 8 −0.2 21 0 34 −0.2 47 0 9 −0.1 22 −0.1 35 0 48 0.1 10 0.2 23 0 36 0.3 49 0.1 11 0.1 24 0.1 37 −0.1 50 0 12 −0.1 25 0.2 38 0 51 0.2 13 0 26 0.1 39 −0.1 Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. © 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. Share and Cite MDPI and ACS Style Schafrik, S.J.; Wedding, Z.E.; Long, M.W.; Kelley, N.T.; Agioutantis, Z.; Diddle, B.M. Measuring the Airflow Characteristics in a Bourbon Warehouse. 2026, 18, 5797. https://doi.org/10.3390/su18125797 AMA Style Schafrik SJ, Wedding ZE, Long MW, Kelley NT, Agioutantis Z, Diddle BM. Measuring the Airflow Characteristics in a Bourbon Warehouse. . 2026; 18(12):5797. https://doi.org/10.3390/su18125797 Chicago/Turabian Style Schafrik, Steven J., Zachary E. Wedding, Michael W. Long, Nathan T. Kelley, Zach Agioutantis, and Ben M. Diddle. 2026. "Measuring the Airflow Characteristics in a Bourbon Warehouse" 18, no. 12: 5797. https://doi.org/10.3390/su18125797 APA Style Schafrik, S. J., Wedding, Z. E., Long, M. W., Kelley, N. T., Agioutantis, Z., & Diddle, B. M. (2026). Measuring the Airflow Characteristics in a Bourbon Warehouse. , 18(12), 5797. https://doi.org/10.3390/su18125797 Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details . Article Metrics Article metric data becomes available approximately 24 hours after publication online.
