Buildings

Humidity control in residential buildings is fundamental to ensuring indoor comfort, health, and energy efficiency. This study evaluates the relationship between indoor relative humidity and its impacts on thermal comfort, HVAC energy performance, biological activity, and material durability during the cooling season. Through literature and thermodynamic analysis, the results suggest that moderately higher RH levels to the common 50% recommended can improve thermal comfort and reduce cooling energy consumption without increasing health or material risks. The analysis concludes that humidity itself is not inherently detrimental; rather, condensation is the critical mechanism behind health and material degradation. Consequently, operating residential cooling systems within a controlled upper humidity at 60% offers measurable energy benefits while maintaining occupant well-being and building integrity.

This study presents a terrestrial−laser−scanning−based scan−to−BIM workflow that transforms point cloud data into a BIM−based digital twin and analyzes how data collected with LiDAR (Light Detection and Ranging) can be converted into an information−rich model using Autodesk ReCap and Revit. Point clouds provided by laser scanning were processed in the ReCap environment and imported into Revit in an application that took place within an industrial facility of approximately 240 m² in Izmir. The scans were registered and pre−processed in Autodesk ReCap 2022 and modeled in Autodesk Revit 2022, with visualization updates prepared in Autodesk Revit 2023. Geometric quality was evaluated using point−to−model distance checks, since the dataset was imported in a pre−registered form and ReCap did not provide station−level RMSE values. The findings indicate that the ReCap–Revit integration offers high geometric accuracy and visual detail for both building elements and production−line machinery, but that high data density and complex geometry limit processing performance and interactivity. The study highlights both the practical applicability and the current technical limitations of terrestrial−laser−scanning−based scan−to−BIM workflows in an industrial context, offering a replicable reference model for future digital twin implementations in Turkey.

Vibration control for over-track structures is a key challenge in urban rail transit. To systematically investigate the determining effects of building height and train speed on dynamic response, this study developed a novel moving excitation system. Unlike conventional fixed-point or shaking table methods, this system faithfully reproduces the spatio-temporal “scanning effect” of train loads. In conjunction with a 1:20 modular scaled physical model, a systematic experimental investigation was conducted on structures of different heights (2, 5, 8, 11, and 15 stories) under various train speeds (60, 80, and 100 km/h), with an experimental uncertainty controlled within ±6%. The results revealed two distinct patterns: low-rise rigid structures (≤5 stories) exhibited a monotonic amplification of vibration (top-floor response amplified by 13–28%), whereas mid-to-high-rise flexible structures (≥8 stories) displayed an “attenuation-followed-by-amplification” pattern, with mid-height vibration levels reduced by over 50%. This transition is attributed to a shift in structural dynamics, as the fundamental frequency decreases from approximately 230 Hz (2-story) to approximately 100 Hz (15-story). Furthermore, linear regression analysis (R² > 0.93) confirmed that while train speed linearly scales the response amplitude, the distribution pattern is strictly dictated by the structure’s intrinsic low-order modes. These findings provide a quantified theoretical basis for vibration mitigation in over-track developments.