Door Opening Research Articles

Experimental investigation of the effect of phase change material on backup time and equivalent energy consumption of domestic refrigerator

Load shedding is a significant problem in rural areas. During a power outage, the cabin temperature of a refrigerator increases owing to the heat gain. In practice, a door should be opened to load and unload refrigerator products, particularly when the power failure period is longer. The use of a phase-change material (PCM) in the refrigerator cabin restricts the increase in temperature and provides a backup time that reduces energy consumption. Door-opening tests are essential during a power cut-off time to investigate the reduction in backup time owing to door openings. This article presents an experimental investigation on the influence of PCM masses of potassium chloride (KCl), sodium chloride (NaCl), and sodium fluoride (NaF) dissolved in water on the backup time and equivalent energy consumption of a domestic refrigerator for closed and open doors according to the standards IS 1476 and IEC 62552:2015. The backup time of closed-door tests was significantly increased by the PCM for all masses, i.e., between 15 and 200 min in absolute terms and between 14% and 182% in relative terms. The backup time for the closed-door tests was 1.8–1.03 times longer than that for the door-opening tests. The backup time of door-opening tests decreased significantly owing to heat entering the cabin for all masses, i.e., between 50 and 10 min in absolute terms and between 45.45% and 3.23% in relative terms. The equivalent energy consumption of a refrigerator decreased with an increase in PCM mass. In closed-door tests, it varied from 0.55 to 0.41 kWh.6-1 h for the 0–1.75 kg mass of all tested PCMs. In the door-opening tests, the equivalent energy consumption increased owing to door opening. The equivalent energy consumption for the door-opening tests was 1.12–1.02 times larger than that for the closed-door tests.

Numerical investigation on composite enclosure walls of RC frames infilled with autoclaved aerated concrete panels under cyclic loads

To promote the application of prefabricated walls and autoclaved aerated concrete (AAC) panels in the Metro industry, the seismic resistance investigations on composite enclosure walls (CEWs) of reinforced concrete (RC) frames infilled with AAC panels suitable for the Metro station were performed. Based on the field test arrangement, the corresponding finite element (FE) models were established and verified according to the experimental results. Moreover, the parametric studies, including with or without AAC infill panels, the compressive strength and thickness of the AAC panels, the compressive strength of frame concrete, and the door opening location and width, were further investigated to explore the structural behavior under cycle loads. The results indicate the seismic performance of CEWs can be effectively improved by infilling AAC panels. The increase in the strength and thickness of AAC panels could enhance the load-bearing capacity and ductility of CEWs. The structural stiffness and cumulative energy dissipation of CEWs are increased with the increasing thickness of AAC panels. The increased range of the peak load, ductility, initial stiffness, and cumulative energy dissipation of CEWs would be maintained within 20.5 % when the concrete strength of the RC frame increases from 35 MPa to 45 MPa. With increasing distance between the constructional column and the door opening, the load-bearing capacity of CEWs is significantly decreased, while the ductility is enhanced. The high initial stiffness could be obtained when the door opens near the constructional column. The load-bearing capacity and initial stiffness of CEWs would be decreased with increasing width of the door opening, while the insignificant effect of the changed door opening width on the ductility.

Developing Customer Loss Function for Door Opening Angle in Passenger Cars: Balancing the Ergonomic Performance between “Entry/Exit (Ingress/Egress) Accommodation” and Door Reachability

<div>Occupant packaging is one of the key tasks involved in the early architectural phase of a vehicle. Accommodation, as a convention, is generally considered related to a car’s interior. Typical roominess metrics of the occupant like hip room, shoulder room, and elbow room are defined with the door in its closed condition. Several other roominess metrics like knee room, leg room, head room, and the like are also specified. While all the guidelines are defined with doors in their closed condition, it is also important to consider the dynamics that exist while the occupant is entering the vehicle. This article expands the traditional understanding of occupant accommodation beyond conventionally considering the vehicle interior’s ability to accommodate anthropometry. It broadens the scope to include dynamic conditions, such as when doors are opened, providing a more realistic and practical perspective. As a luxury car manufacturer, it is important to ensure the best overall customer experience at each touch point of the vehicle. When the customer enters the vehicle, there should be sufficient space provided by the door opening angle for a comfortable entry. The larger the opening angle, the better is the “entry accommodation” and vice versa. However, a wide-open door also necessitates the customer to bend more, after being seated, to reach its handle and close it. Thus, it becomes a compromise between what is possible as accommodation while the customer is entering the vehicle and how easy it is to close the door after being seated. The same logic holds good while the customer opens the door and exits the vehicle. This article aims to develop a customer loss function (CLF) between the two conflicting criteria by considering relevant anthropometric distribution of customers. This study focuses on driver compartment and the methodology developed is also pertinent to rear compartment with minor adaptations. Since driver’s seating position is heavily dependent on anthropometry, finer details of occupant seating position are also considered in this study. CLF developed in this article will help the designer and packaging engineers in making informed decisions on the door opening angle, by being conscious of the customer loss/gain for defined performance metrics.</div>

Research on Microclimate Optimization of Traditional Residential Buildings in Central Anhui Based on Humid and Hot Climate Characteristics and Regional Architectural Features

This study examines how building space, materials, and structure affect the microclimate of Liu Tong Xinglongzhuang in central Anhui, known for its hot, humid climate and distinct architecture. Using qualitative and quantitative methods, including field monitoring, PHOENICS simulation, and Ladybug Tools, the following conclusions were drawn: (1) Building materials: wood reduces indoor temperature; a glass roof over the patio lowers temperature and improves wind speed; and reducing tile area decreases solar radiation. (2) Building space: optimal comfort in stairwells is achieved with a length-to-width ratio of 1.5:1 and height-to-width ratio of 2:1; courtyards are most comfortable with a length-to-width ratio of 2.5:1 and height-to-width ratio of 1.5:1; walk-through halls are optimal with a length-to-width ratio of 2:1 and height-to-width ratio of 1.5:1; and wings achieve the highest comfort with a length-to-width ratio of 2.5:1 and height-to-width ratio of 1.5:1. (3) Building structure: optimal wind speed and temperature are achieved with specific window height-to-width ratios of 1:1 for exterior and 1.5:1 for interior windows; the lowest temperatures occur at 2:1 ratios; hexagonal exterior and circular interior windows maximize wind speed and temperature reduction; and smaller exterior door openings lower indoor temperatures and are best achieved with an interior door ratio of 2:1. These findings offer valuable data and methods for optimizing the microclimate of traditional houses, with significant practical implications.

Unintended Consequences of Urban Expansion and Gold Mining: Elevated Indoor Radon Levels in Gauteng Communities’ Neighboring Gold Mine Tailings

The province of Gauteng in South Africa has a rich history of gold mining, which has driven economic growth and urbanization. Gold mining has also created over 270 gold mine tailings (GMT), now surrounded by human settlements due to a housing shortage. These GMT pose a health risk as they harbor elevated uranium, which over time undergoes radioactive decay to produce radon, a known lung carcinogen. This study aimed to investigate the potential correlation between the proximity to gold mine tailings (GMT) and indoor radon concentrations in Gauteng’s residential dwellings. Volume activity of radon (VAR) inside 330 residential dwellings was measured in residential dwellings located proximally (<2 km) and distally (>2 km) to gold mine tailings using AlphaE radon monitors during winter. An interviewer-administered questionnaire was utilized to obtain data on factors that may influence indoor radon activities. Descriptive statistics and bivariate logistic regression analyzed the influence of proximity to gold mine tailings and dwelling characteristics on VAR. Furthermore, VAR was compared to the World Health Organization (WHO) radon reference level of 100 Bq/m3. Residential dwellings near gold mine tailings had significantly higher average indoor radon concentrations (103.30 Bq/m3) compared to the control group (65.19 Bq/m3). Residential dwellings proximal to gold mine tailings were three times more likely to have VAR beyond the WHO reference level of 100 Bq/m3. Furthermore, they had estimated annual effective doses of 2.60 mSv/y compared to 1.64 mSv/y for the control group. This study highlighted a concerning association between proximity to gold mine tailings and elevated indoor radon levels. Public health interventions prioritizing residential dwellings near gold mine tailings are crucial. Educational campaigns and financial assistance for radon mitigation systems in high-risk dwellings are recommended. Residents near gold mine tailings are encouraged to ensure continuous natural ventilation through frequent opening of windows and doors.

Beware of Strangers: Dogs' Empathetic Response to Unknown Humans.

Empathy is a complex cognitive ability that has been studied in many social animals, including dogs. Previous studies have found that dogs would rescue their distressed owner more quickly than a calm owner and that dogs respond physiologically and behaviorally to the sound of crying strangers. However, no studies have explored the empathetic and emotional contagion capabilities of dogs towards strangers in rescue paradigms. In the present study, a stranger was placed behind a clear door and was told to cry (distress) or hum (neutral). The dogs' door opening, stress behaviors, tone of approach, and physiological responses were measured. Dogs did not open more frequently or more quickly for the stranger in the distressed condition compared to the neutral condition. Additionally, there was no significant difference between the behavioral or physiological indicators of stress across conditions. It was also found that non-openers were reported by owners to have more fear and, in the empathy test, were more aggressive and fearful in their tone of approach. These results suggest that dogs may be less likely to exhibit empathy-like behaviors to unknown humans in an unfamiliar environment and that owners may be necessary to moderate a dog's stress to show empathetic behaviors.

A versatile door opening system with mobile manipulator through adaptive position-force control and reinforcement learning

The ability of robots to navigate through doors is crucial for their effective operation in indoor environments. Consequently, extensive research has been conducted to develop robots capable of opening specific doors. However, the diverse combinations of door handles and opening directions necessitate a more versatile door opening system for robots to successfully operate in real-world environments. In this paper, we propose a mobile manipulator system that can autonomously open various doors without prior knowledge. By using convolutional neural networks, point cloud extraction techniques, and external force measurements during exploratory motion, we obtained information regarding handle types, poses, and door characteristics. Through two different approaches, adaptive position-force control and deep reinforcement learning, we successfully opened doors without precise trajectory or excessive external force. The adaptive position-force control method involves moving the end-effector in the direction of the door opening while responding compliantly to external forces, ensuring safety and manipulator workspace. Meanwhile, the deep reinforcement learning policy minimizes applied forces and eliminates unnecessary movements, enabling stable operation across doors with different poses and widths. The RL-based approach outperforms the adaptive position-force control method in terms of compensating for external forces, ensuring smooth motion, and achieving efficient speed. It reduces the maximum force required by 3.27 times and improves motion smoothness by 1.82 times. However, the non-learning-based adaptive position-force control method demonstrates more versatility in opening a wider range of doors, encompassing revolute doors with four distinct opening directions and varying widths.

Visual Mapping of Operating Theater Team Dynamics and Communication for Reflexive Feedback and Surgical Practice Optimization.

Effective operating theater (OT) communication and teamwork are essential to optimal surgical outcomes. We mapped the OT team dynamics and infection control practices using visual methods to guide reflexive feedback and optimize perioperative practices. Data were gathered from adult gastrointestinal surgical teams at a tertiary hospital in India using observations, sociograms (communication mapping tool), and focus group discussions (FGDs). Our methods aimed to map team communication, roles and responsibilities in infection-related practices, and door openings. Qualitative data were thematically analyzed. Quantitative data were analyzed using descriptive statistics. Data were gathered from 10 surgical procedures (over 51 hours) using 16 sociograms, 15 traffic flow maps, and 3 FGDs. Senior surgeons directly influence team hierarchies, dynamics, and communication. While the surgeons, anesthetic residents, and technicians lead most tasks during procedures, the scrub nurse acts as a mediator coordinating activity among role players across hierarchies. Failing to provide the scrub nurse with complete details of the planned surgery leads to multiple door openings to fetch equipment and disposables. Traffic flow observed in 15-minute intervals corresponds to a mean frequency of 56 door openings per hour (min: 16; max: 108), with implications for infection control. Implementing the World Health Organization surgical safety checklist was inconsistent across pathways and does not match reported compliance data. Human factors research is important in optimizing surgical teamwork. Using visual methods to provide feedback to perioperative teams on their communication patterns and behaviors, provided an opportunity for contextualized enhancement of infection prevention and control practices.

Car wash noise reduction - case study

A car wash is installed in one corner of a large industrial building with the exit feeding into the building interior. The building interior is largely open space with a high roof. This houses multiple activities going on at any given time including part fabrication and vehicle retrofitting. The space available for the car wash necessitates the exit door to open during the drying cycle. The blower noise during the drying cycle with the exit door open is not loud enough to require hearing protection in the facility. The functions held within the space eventually expanded to include meetings requiring speech communication. The noise during the drying cycle was loud enough to disrupt audibility. An ad hoc team worked to reduce noise levels sufficiently to allow all other activities to continue without noise disruption during car wash operation. This paper addresses the diagnostic work and countermeasures put in place to achieve this goal.

Responsibility as the door opener toward trust: How powerholders construe and express their power impacts others' willingness to trust them

Responsibility as the door opener toward trust: How powerholders construe and express their power impacts others' willingness to trust them

Interfacial exchange of airflow and bacteria-carrying particles induced by door opening and foot traffic in an operating room

Maintaining high air cleanliness in operating rooms (ORs) can reduce surgical site infections (SSIs). However, door openings and foot traffic during surgery may allow the intrusion of contaminated air and increase microbial contamination in ORs. In this study, numerical methods were applied to investigate the dynamic airflow and bacteria-carrying particle (BCP) dispersion during sliding door opening and foot traffic in an OR. The door movement and realistic human walking were modeled by the dynamic mesh technique. The interfacial exchange of airflow and BCPs was evaluated as the medical staff entered and exited the OR under fixed supply air temperatures and various differential pressures, respectively. Results showed that walking across the door interface caused a sharp increase in airflow exchange between the OR and the anteroom (ANT). An average walking speed of 1.2 m/s induced a maximum inflow rate of approximately 1.32 times greater when entering the OR than when leaving the OR. Once the door was open, the temperature difference convection effect was more significant than the pressure difference outflow effect. Differential pressure outflow indirectly affected airflow exchange at the door interface by changing the direction and temperature of airflow in the ANT. Whether entering or leaving the OR, the BCP intrusion ratios were on average 1.5 times higher at high pressure differentials (15 and 20 Pa) than at low pressure differentials (5 Pa and 10 Pa). This study is expected to improve the understanding of the impact of door opening and foot traffic on OR air quality during surgery.

Recovering energy from door opening and closing process using a parallel crank-slider harvester in buildings

Recovering kinetic energy from the environment is mostly focused on the natural environment, while there is also a huge energy in the human living environment. The swing door is an indispensable equipment in the human living environment. The bidirectional swing of the door opening and closing process is rich in energy generated by human motion and thus has a large potential for energy recovery. An energy harvester for recovering bidirectional kinetic energy of the door in buildings is proposed, fabricated, analyzed, and tested. The energy harvester consists of a parallel crank-slider mechanism, a transmission mechanism and a power generation module. The external linkage is used to connect the door and the energy harvester to transmit the bidirectional swing of the door. The parallel crank-slider mechanism is coupled with two one-way bearings. This can realize the conversion of the bidirectional swing of the door to the unidirectional rotation of the central shaft. The final mechanical rectification effect is achieved. Kinematic and dynamic analyses are performed to determine the factors affecting the power generation performance. A prototype is fabricated, and experiments are conducted on it by simulating the process of opening and closing the door. The experimental results are consistent with the simulation ones. At a normal opening velocity of 90° s−1, the maximum open-circuit voltage of the harvester is 7.06 V and the average output power is 1.03 W. The highest efficiency of the harvester can reach 69.65%. The recovered energy is capable of powering the smart door lock for at least 150 s, as well as powering devices such as door lights and doorbells. This can meet the power supply needs of most electronic devices on doors in human life.

The relationship between occupant behaviour and indoor air quality in Malaysian hospital outpatient departments: A multistage cross-sectional study

IntroductionPoor indoor air quality (IAQ) in healthcare settings may adversely impact occupants’ well-being and promote transmission of infectious respiratory disease. However, evidence on its potentially modifiable determinants, including occupant behaviour, remains scarce. This study aims to determine the relationship between occupant behaviour and IAQ in Malaysian hospital outpatient departments (OPDs). MethodsA multistage cross-sectional study of six randomly selected Malaysian public hospital OPDs was conducted. In stage one, IAQ parameters, including temperature, relative humidity (RH), air velocity (AV), carbon dioxide (CO2), total bacterial count (TBC), and total fungal count (TFC) were measured. In stage two, an observation form based on the Korsavi and Montazami tool for measuring adaptive behaviour was used to examine occupant density, activities, and operation of building envelopes and appliances. Simple correlation, partial correlation, and linear regression analyses were performed to examine the relationship between occupant behaviour and IAQ parameters. ResultsThe IAQ of selected hospital OPDs complied with established standards, except for temperature and AV. Occupant density was positively correlated with temperature and CO2. Meanwhile, occupants' activities including slow walking and brisk walking were positively correlated with temperature, AV, CO2, TBC and TFC. Conversely, occupants' opening of windows and doors were positively correlated with temperature and AV but negatively correlated with CO2, TBC and TFC. Finally, turning on fans was positively correlated with AV but negatively correlated with TBC, whereas turning on air conditioner was positively correlated with CO2. Among occupants’ behaviour, opening of windows and doors contributed the most to variation in IAQ parameters. ConclusionsThe study findings suggest that IAQ in hospital OPDs are influenced by occupant density, activities, and operation of doors, windows, and appliances. Prospective hospital IAQ guidelines should incorporate policies and measures targeting these factors to ensure occupants’ best practices in maintaining healthy hospital indoor air environments.

Diesel Engine Age and Fine Particulate Matter Concentrations in School Buses

In this study, we examine and assess the potential impact of diesel engine age on the levels of fine particulate matter (PM2.5) in school buses. The concentration of air pollutants is influenced by several factors, including the technical characteristics of the bus and its engine, the type of fuel used, the length of the commute, the weather conditions, and the ambient air pollution. The behavior of the bus on the road, during the commute to and from school, is also important. This includes its position in traffic, the number of bus stops, boarding procedures, as well as the opening of doors and windows. Data were collected by accompanying a student during their commute to and from school, with bus commutes serving as the sampling unit. A semi-parametric regression was applied to assess the link between the PM2.5 concentration and the bus engine age. It was demonstrated that the bus engine age has a statistically significant positive correlation with the PM2.5 concentration inside the bus. The fine particulate matter concentrations during boarding at the school also depend on the engine age, indicating that bus idling affects the PM2.5 concentration. In the first two minutes before boarding in front of the school and the first two minutes inside the bus, the PM2.5 concentrations were 26.3 and 40.3 μg/m3, respectively. The findings of this study highlight the impact of bus engine age on the PM2.5 concentration, showing that the PM2.5 concentration increases with the engine age. However, the effect becomes less visible as the duration of the bus ride increases.

Mitigating SSIs: focus on physical operation rooms environmental factors

Background: Surgical site infections (SSIs) are associated with increased morbidity, monetary loss and mortality. The physical aspects of the operation room (OR) including airflow, humidity, pressure, and particulate counts are essential part of SSI prevention. Humidity control is vital to avoid static electricity buildup.Temperature control helps prevent hypothermia. Limiting OR traffic and door opening are essential to prevent airflow disturbance and minimze particles in OR environment. We have recently studied electronic monitoring of OR traffic and the traffic was higher than what was expected. Our aim was to evaluate our real-life measurement of these OR parameters as part of SSI prevention bundle. Methods: This is a prospective study focused on the OR physical environmental factors as part of operative SSI prevention bundle. The study was conducted for 4 weeks at an academic medical center. The study was conducted in two different generations of OR for neurosurgical and ophthalmologic procedures. We performed direct observation of OR traffic as well as environmental parameters (temperature, humidity, pressure, and particulate count) for the entire length of the procedure. We used both directly measured data as well as automated data generated by facilities. Results: The study showed that temperature, humidity, and pressure wer tightly controlled in the OR. This observation was consistent between manual data and automatically generated data. The OR traffic was not easily monitored by the current automatic data and was measured by direct observation. The correlations between particulate count and OR traffic was strongest for 0.3μm (0.7370, and weakest for 1.0μm ( 0.087). The 5.0μm particulate size had a moderate positive correlation of 0.344, Additionally, shorter procedures had less particulate matter in the OR environment. Automated data were only available in the new ORs but could not predict traffic without automated door monitors. But the automated data could easily portray the temperature, humidity and pressure minute by minute. Conclusion: OR traffic increases the particle count particularly the small size. Other physical aspects of the OR environment were tightly controlled. The ability to automatically monitor OR parameters could be extremely helpful for assuring patient safety as well as reviewing OR factors in SSI cases.

High dynamic-range and portable magnetometer using ensemble nitrogen-vacancy centers in diamond.

Nitrogen vacancy (NV) centers in diamonds have been explored for a wide range of sensing applications in the last decade due to their unique quantum properties. In this work, we report a compact and portable magnetometer with an ensemble of NV centers, which we call the Quantum MagPI (Quantum Magnetometer with Proportional Integral control). Our fully integrated compact sensor assembly and control electronics fit inside a 10 × 10 × 7cm3 box and a 30 × 25 × 5cm3 rack-mountable box, respectively. We achieve a bandwidth normalized sensitivity of ∼10 nT/Hz. Using closed-loop feedback for locking to the resonance frequency, we extend the linear dynamic range to 200 μT (20× improvement compared to the intrinsic dynamic range) without compromising the sensitivity. We report a detailed performance analysis of the magnetometer through measurements of noise spectra, Allan deviation, and tracking of nT-level magnetic fields in real-time. In addition, we demonstrate the utility of such a magnetometer by real-time tracking of the movement of an elevator car and door opening events by measuring the projection of the magnetic field along one of the NV-axes under ambient temperature and humidity conditions.

Green Open Space Design in Papan Island Township Arrangement

: The purpose of open space is as a forum for organizing activities that are not only limited to human activities but also as a forum for nature conservation Papan Island has the potential as a tourist destination with its cultural wealth and biodiversity, by creating a space for tourists and still paying attention to the needs of the people of Papan Island and its environment, a tourist area will be created with the concept of Green Open Space (RTH) Method: The method used in this research is the Architectural design method. This method uses an analysis of the activities and needs of tourists and the community on Papan Island. Data obtained through interviews, observations, documentation, and literature studies Results and Discussion: This research makes the concept of shared space in architecture refer to an area or environment designed to be used and enjoyed together by a group of people. Based on the results of the analysis that has been carried out, the following design response will be made, namely making flexible openings such as large sliding door openings but at the same time can be closed. Conclusion This research shows that green spaces can be a key element in creating a healthier, more comfortable, and sustainable environment on Papan Island:

An Analytical Model of Walls with Openings Variation Using the Diagonal Strut Method

Abstract Improving the strength and lateral stiffness values of the reinforced concrete structure can be done by installing the brick wall. The capacity of the reinforced concrete structure cannot be predicted if the wall equipped with openings. Developing the modeling using the diagonal strut method was done in this analytical model for wall with openings in this research. The analytical modeling results will be verified with experimental and analytical models of brick walls with two openings and a door opening show comprehensible results with deviations of 19% and 7.9% for IFOW1, IFOP and IFOW2, respectively. In other words, the analytical equations developed are successfully applied.

Experimental evaluation of performance parameters of a domestic freezer under door opening conditions

The current study focuses on a comprehensive experimental assessment of the cooling system parameters of a domestic-type upright freezer that is equipped with shelves and test packages under periodic door opening conditions, referring to real user scenarios. The influence of varying ambient relative humidity levels as well as the load state of the cabinet are taken into account. The study reveals that both heat and moisture have a crucial effect on the average air temperature inside the cabinet, the temperature of the walls, the transient evaporation and condensation pressure behaviour of the refrigerant, as well as the compressor power, the total operation ratio of the compressor, and the overall amount of energy consumption. The specific performance experiments are conducted at 32 °C ambient and 35 %, 65 %, and 85 % relative humidity conditions with unloaded, half-loaded, and full-loaded cases. The obtained data and results are evaluated between frosting, influenced by altering ambient humidity levels, and cabinet load state under periodic door openings where the variation in energy consumption is clearly measured. Consequently, the amounts of frost accumulation in the cabinet under half and full loaded conditions at 32 °C an 85 % relative humidity conditions are observed to be about 220 g and 270 g, respectively, followed by regular door openings and closings which result in a raise in total energy consumption rate of 7.6 % and 11.2 % compared to the period before the door opening. The frost accumulation in the full loaded condition at 32 °C and 85 % RH is found to be 2.4 times greater than the unloaded condition with a relative humidity (RH) of 35 % whereas the energy consumption is 3.7 times higher.

Operating Room Air May Harbor Pathogens: The Role of an Ultraviolet Air Filtration Unit

BackgroundOne important factor for the prevention of surgical site infections is ultraclean air in the operating room (OR). Still, the direct sterilization potential of most technologies, especially in a dynamic clinical setting, is not well understood. We aimed to determine and compare the microbial presence from the inlet and outlet flow of a filtration unit with crystalline ultraviolet-C (C-UVC) light. MethodsA prospective study was conducted at a single institution, where primary total joint arthroplasty and spine surgeries were performed. The OR was fitted with a positive ventilation system. In addition, a filtration unit with a C-UVC sterilizing light was placed in the OR. The inlet and outlet air flows were swabbed simultaneously and compared. Swabs were processed for culture and next-generation sequencing. ResultsThe mean length of the surgical procedures sampled was 68 ± 13 minutes. Overall, 19 out of 200 (9.5%) swabs isolated microorganisms. Inlet air swabs were positive at a higher rate (16 versus 3%; P < .01) compared to the outlet air swabs. A wide variety of Gram-positive, Gram-negative, and anaerobic bacteria were isolated, but fungi were only recovered from inlet air swabs. The detection of microorganisms was also higher when more door openings were performed (32.5 ± 7.1 versus 27.9 ± 5.6; P < .01). ConclusionsAir swabs mainly isolated microorganisms from the inlet flow to the filtration unit with a C-UVC light. The sterilizing unit counteracted factors affecting the air quality in the OR, namely door openings, surgical personnel, and tissue combustion.