AIR DISTRIBUTION EFFICIENCY WITH A LINEAR SLOT DIFFUSER IN NON-ISOTHERMAL CONDITIONS
DOI:
https://doi.org/10.31650/2786-6696-2025-13-117-124Keywords:
microclimate, thermal comfort, flat jet, air distribution, air flow turbulence.Abstract
Effective provision of a comfortable indoor climate is a key requirement for modern central air ventilation systems. These systems play an important role in creating a healthy and comfortable environment for living, working or relaxing. Taking into account modern architectural trends and design solutions, linear louver diffusers are becoming increasingly popular as air distribution devices. Their aesthetic appeal allows them to be harmoniously integrated into interior design, often making them central elements that emphasize the style of the room.
The design feature of linear louver diffusers lies in their specific structure: they have a small width with a significant length, which distinguishes them from traditional compact diffusers of round or square shape. This feature significantly affects the characteristics of the air jet formed by such diffusers. During the operation of ventilation systems in air conditioning or air heating modes, linear diffusers create unique air flows that differ from compact jets in their behavior, velocity and temperature distribution. These differences must be taken into account at the stages of design, adjustment and operation of ventilation systems in order to ensure their effective operation and achieve an optimal microclimate.
Data obtained from computer modeling and experimental studies play a key role in the development and optimization of ventilation systems with linear louver diffusers. Modeling allows you to predict the behavior of air flows in different conditions, taking into account the geometry of the room, the location of the diffusers and air parameters (temperature, humidity, flow rate). Experimental studies, in turn, confirm theoretical calculations and allow you to refine the parameters of the system. Thanks to an integrated approach that combines modeling and experiments, it is possible to achieve high efficiency of ventilation systems, minimize energy consumption and ensure a comfortable microclimate in the premises.
The use of linear louver diffusers also contributes to reducing noise exposure and uniform air distribution, which is especially important for residential and public spaces. Proper selection and adjustment of such diffusers allows you to avoid areas of air stagnation or excessive turbulence, which can negatively affect the comfort of users. Thus, taking into account the features of linear diffusers at all stages ‒ from design to operation ‒ is the key to creating effective and aesthetically attractive ventilation systems that meet modern requirements for comfort and energy efficiency.
References
[1] ASHRAE/ANSI Standard 55-2010 Thermal environmental conditions for human occupancy. Atlanta, USA, 2010.
[2] A. Li, C. Yang, T. Ren, X. Bao, E. Qin, R. Gao, 2017, "PIV experiment and evaluation of air flow performance of swirl diffuser mounted on the floor", Energy and Buildings, vol. 156, pp. 58–69, 2017. doi.org/10.1016/j.enbuild.2017.09.045.
[3] M. Borowski, K. Zwolińska, J. Halibart, "Air distribution assessment-ventilation systems with different types of linear diffusers". [Online]. Available: https://www.aivc.org/sites/default/files/1_C28.pdf. 2023.
[4] O.T. Vozniak, I.Ye. Sukholova, Kh.V. Myroniuk, "Doslidzhennia prystroiu dlia povitrorozpodilu zakruchenymy i nastylnymy strumynamy u zminnomu rezhymi", Eastern-European Journal of Enterprise Technologies, vol. 6, no. 7(78), pp. 15, 2015, doi.org/10.15587/1729-4061.2015.56235.
[5] M. Borowski, M. Karch, R. Łuczak, P. Życzkowski, M. Jaszczur, "Numerical and experimental analysis of the velocity field of air flowing through swirl diffusers", E3S Web Conference, vol. 128, pp.1-6, 2019. doi.org/10.1051/e3sconf/201912805003.
[6] Y.H. Yau, K.S. Poh, A. Badarudin, "A numerical airflow pattern study of a floor swirl diffuser for UFAD system", Energy and Buildings, vol. 158, pp. 525-535, 2018. doi.org/10.1016/j.enbuild.2017.10.037.
[7] G. Cao, M. Ruponen, K. Hagström, J. Kurnitski, "Experimental studies on air distribution using ceiling slot diffusers in a room", International Journal of Ventilation, vol 9 (4), pp. 385-392, 2016. doi.org/10.1080/14733315.2011.11683896.
[8] O. Voznyak, N. Spodyniuk, Yu. Yurkevych, I. Sukholova, O. Dovbush, "Enhancing efficiency of air distribution by swirled-compact air jets in the mine using the heat utilizators", Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, vol. 5 (179), pр. 89 – 94, 2020. doi:10.33271/nvngu/2020-5/089. doi.org/10.33271/nvngu/2020¬5/089.
[9] B. Both, Z. Szánthó, R. Goda, "Evaluation of air diffuser flow modelling methods experiments and computational fluid dynamics simulations", Energy Procedia, vol. 112, pp. 352-359, 2017. doi.org/10.1016/j.buildenv.2004.06.021.
[10] H. Yu, C-M. Liao, H-M. Liang, "Scale model study of airflow performance in a ceiling slot-ventilated enclosure: isothermal condition", Building and Environment, vol. 38, pp. 1271-1279, 2003. dx.doi.org/10.1016/S0360-1323(03)00131-8.
[11] M.M. Keshtkar, M. Nafteh, "Investigation of influence of linear diffuser in the ventilation of operating rooms", Advances in Energy Research, vol. 4, pp. 239-253, 2016. dx.doi.org/10.12989/eri.2016.4.3.239.
[12] D. Law, A. Valdez, "Computational modeling and simulations of isothermal plane (linear) air jet velocity profile for slot diffusers", ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) 7, 2014. doi.org/10.1115/IMECE2014-37317.
[13] M. Borowski, R. Łuczak, J. Halibart, K. Zwolińska-Glądys, M. Karch, "Airflow fluctuation from linear diffusers in an office building: the thermal comfort analysis", Energies, vol. 14, pp. 4808, 2021. doi.org/10.3390/en14164808.
[14] S. Sheng, T. Yamanaka, T. Kobayashi, "Heating and ventilation performance investigation of a novel linear slot diffuser with adaptive outlet area for near window applications", Building and Environment, vol. 244, 2023, doi.org/10.1016/j.buildenv.2023.110813.
[15] D.Y. Park, S. Chang, "Numerical analysis on the thermal and air exchange performance of linear slot diffuser length variations in an office space", Indoor Air 2014 - 13th International Conference on Indoor Air Quality and Climate, pp. 334–341, 2014.
[16] Y. Chemerynskyi, O. Voznyak, "Some characteristics of air distribution at application of linear crevice diffuser", Energy Engineering and Control Systems, vol. 11, pp. 21 – 26, 2025. doi.org/10.23939/jeecs2025.01.021.
[17] J. Zhang, H. Kwok, J. Cheng, "Heritage Building Air Diffusion Performance Index: HVAC Diffuser Layout Evaluation for Heritage Building Preservation", Proceedings of the 20th International Conference on Computing in Civil and Building Engineering (ICCCBE), vol. 628, Montréal, Québec, Canada, 2024.
[18] M. Madaliev, M. Usmonov, F. Tillaboyeva, A. Mamatov, B. Otakulov, S. Ro’zaliyev, Z. Mamatova, "Comparison of numerical results of RSM turbulence models for the problem of asymmetrical plane diffuser", BIO Web of Conferences, vol. 145, 2024. doi.org/10.1051/bioconf/202414503036.
[19] T. Eraslan, C. Keskin, M. Mengüç, "Airflow Characteristics and Thermal Comfort of Air Diffusers", ASME 2023 Heat Transfer Summer Conference, 2023. doi.org/10.1115/ES2023-107024.
[20] W.K. Chow, L.T. Wong, "Experimental studies on air diffusion of a linear diffuser and associated thermal comfort indices in an air-conditioned space", Building and Environment, vol. 29, pp. 523–530, 1994. doi.org/10.1016/0360-1323(94)90011-6.
[21] M. Alkhalaf, A. Ilinca, M. Hayyani, F. Martini, "Impact of Diffuser Location on Thermal Comfort Inside a Hospital Isolation Room", Designs, vol. 8, 2024. doi.org/10.3390/designs8020019.
[22] O. Voznyak, V. Bokhan, I. Sukholova, M. Kasynets, H. Klymenko, "Improvement of air distribution in a room with swirled air jets", Theory and Building Practice, vol. 7, pp. 112–116, 2025. doi.org/10.23939/jtbp2025.01.112.
[23] A. Erdogan, I. Aksoy, S. Canbazoğlu, "Effects of geometric parameters of perforated diffuser on sound pressure level sourced by airflow", Black Sea Journal of Engineering and Science, vol. 7, 2024. doi.org/10.34248/bsengineering.1421571.
[24] H. Schlichting, Boundary Layer Theory (6th Ed.), McGraw-Hill, New York, 1968.
[25] O. Voznyak, Y. Chemerynskyi, I. Sukholova, M. Kasynets, O. Savchenko, "Improving the efficiency of air distribution in a room with a linear slot diffuser", Theory and Building Practice, vol. 7, pp. 106–111, 2025. doi.org/10.23939/jtbp2025.01.106.
[26] O. Voznyak, I. Sukholova, N. Spodyniuk, M. Kasynets, O. Savchenko, O. Dovbush, O. Datsko, "Enhancing of ventilation efficiency of premise due to linear diffuser", Pollack Periodica, vol. 18, pp. 107-112, 2023. doi.org/10.1556/606.2023.00750.
Downloads
Published
Issue
Section
License
Copyright (c) 2025 MODERN CONSTRUCTION AND ARCHITECTURE

This work is licensed under a Creative Commons Attribution 4.0 International License.




