Article
Construction & Building Technology
Ji-Su Choi, Gun-Joo Jung, Kyu-Nam Rhee
Summary: Ceiling radiant cooling panel (CRCP) systems have been widely used for space cooling due to their high thermal comfort and energy efficiency. However, the cooling capacity of CRCP systems can be limited due to the need to maintain the panel surface temperature above the dew-point temperature. In this study, a fan-assisted ceiling radiant cooling panel (FCRCP) system was developed using small and low-cost fans to enhance the cooling capacity without major modifications to the existing architectural or mechanical elements. Experimental and numerical analysis results showed that the FCRCP system can significantly improve the cooling performance compared to conventional CRCP systems.
ENERGY AND BUILDINGS
(2023)
Article
Construction & Building Technology
Jun Shinoda, Ongun B. Kazanci, Katsuaki Hidari, Hiroki Watanabe, Yoshimi Takahashi, Shin-ichi Tanabe
Summary: This study aims to quantify the effect of plenum temperature on the room-and plenum-side cooling of suspended radiant ceiling panels and proposes a methodology to measure and predict the cooling at both sides of the panel.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Xingguo Guo, Shuangshuang Wan, Wenhua Chen, Hui Zhang, Edward Arens, Yuanda Cheng, Wilmer Pasut
Summary: This study evaluates the heat transfer from radiant ceilings with suspended acoustical panels and investigates the impact of an upward-directed ceiling fan on heat exchange. The simulation results show that increasing the fan speed enhances convective and total heat transfer for the radiant panel. Additionally, increasing the fan speed and decreasing the coverage ratio of acoustical panels can reduce temperature nonuniformity and improve thermal comfort in the occupied part of the room. The study suggests that using an upward-directed ceiling fan is a valuable approach to increase radiant surface temperatures, save cooling energy, and reduce surface condensation risk.
ENERGY AND BUILDINGS
(2023)
Article
Thermodynamics
Kilian Edwards, Mattia De Rosa, Donal P. Finn
Summary: A novel control strategy requiring minimal input data is proposed to optimize fan speed and reduce energy consumption in fan coil units. Different control models are implemented to predict capacities and total power consumption. Results show significant energy savings compared to fixed speed settings.
APPLIED THERMAL ENGINEERING
(2021)
Article
Construction & Building Technology
Shufan Yang, Yuxuan Zhang, Yongling Zhao, Juan F. Torres, Xiaolin Wang
Summary: Passive cooling using phase change materials (PCMs) is a promising technique to stabilize indoor air temperature and reduce building energy demand. This study investigates the phase change behavior and thermal performance of PCM ceiling panels with different geometries. The results show that the pyramid array panel performs better than the tetrahedral-based panel, and hanging the panel enhances heat transfer compared to direct attachment to the ceiling.
ENERGY AND BUILDINGS
(2023)
Article
Computer Science, Information Systems
N. C. Lenin, Sanjeevikumar Padmanaban, Mahajan Sagar Bhaskar, Massimo Mitolo, Eklas Hossain
Summary: This article extensively discusses the development of energy-efficient ceiling fans, covering past, present, and future trends, including various aspects such as electric motors, controllers, mechanical designs, etc. Furthermore, it provides a comprehensive review of modern energy-efficient fans' technical and performance indices, linking energy consumption reduction with carbon emissions reduction, and highlighting the potential for future energy efficiency developments.
Article
Energy & Fuels
Andres Gallardo, Umberto Berardi
Summary: The study developed a RCP system with PCM and established design criteria through parametric dynamic simulations, showing effective results in a small test chamber.
Article
Construction & Building Technology
Andres Gallardo, Umberto Berardi
Summary: This study proposes an innovative cooling system utilizing macro-encapsulated phase change materials (PCM) to manage cooling loads in office buildings. The system's performance and improvement in indoor thermal environment are evaluated through experiments.
ENERGY AND BUILDINGS
(2022)
Article
Construction & Building Technology
Ahmet Dogan, Nurullah Kayaci, Hakan Demir, Mustafa Kemal Sevindir
Summary: This study compares the thermal comfort performances of different radiant systems (ceiling, wall, and wall + ceiling) with a fan coil system. The results show that the thermal environment of radiant systems is more uniform with low air temperature stratification and velocity, resulting in smaller vertical temperature differences. Active cooling of ceiling + wall radiant panels can provide acceptable indoor comfort in one experimental condition.
ENERGY AND BUILDINGS
(2022)
Article
Green & Sustainable Science & Technology
Shuai Li, Zhihua Zhou, Junwei Liu, Ji Zhang, Huajie Tang, Zhuofen Zhang, Yanling Na, Chongxu Jiang
Summary: Radiative cooling (RC) is a passive cooling technology that can efficiently cool photovoltaic (PV) panels without consuming energy or producing pollution. This paper proposes an indirect cooling system for PV panels based on RC, which utilizes a cold storage module and water system to reduce the temperature and increase the power conversion efficiency (PCE) of the PV panels. Experimental results demonstrate that the system effectively decreases the average temperature of the PV panels and improves the PCE, and the inclusion of a cover shield and large water tank capacity further enhances the system efficiency.
Article
Construction & Building Technology
Ziwen Zhong, Wei Ma, Shuhuai Yao, Xiangguo Xu, Jianlei Niu
Summary: This study estimated the enhanced cooling capacity of radiant ceiling panels (RCP) through latent heat transfer. Experimental results confirmed that the condensation heat transfer of a superhydrophobic aluminum surface can be predicted using the heat and mass transfer analogy method. The total heat flux of RCP with latent heat transfer was found to increase by 3% to 500% compared to RCP with only sensible cooling.
ENERGY AND BUILDINGS
(2022)
Article
Thermodynamics
Mehmet Ali Yildirim, Artur Cebula, Maciej Sulowicz
Summary: This paper proposes an innovative thermal collector that couples the thermal behavior of photovoltaic modules and a designed cooling system to enhance the thermal and electrical conversion efficiencies of water-based photovoltaic-thermal systems. The results show that the designed cooling system achieves better performance and significantly improves the thermal and electrical conversion efficiency compared to existing solutions in the literature.
Article
Construction & Building Technology
Xiaozhou Wu, Hao Gao, Mingming Zhao, Jie Gao, Zhen Tian, Xiangli Li
Summary: This study experimentally investigated the indoor air distribution and thermal environment in a ceiling cooling room. The results showed that the type of ventilation system significantly affected the indoor air distribution and thermal environment in the ceiling cooling room.
Article
Thermodynamics
Suhil M. Kiwan, Ali M. Khlefat
Summary: An effective photovoltaic thermal regulation technique using porous material confined at the backside of the panel is proposed in this study. Numerical thermal analysis and simulation studied the influence of different parameters on the conversion efficiency of the PV module, showing that increasing the porous fins and porous layer can enhance efficiency and reduce friction. Additionally, increasing the emissivity of the duct base wall can enhance the cooling effect.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Construction & Building Technology
Qiong Chen, Nan Li
Summary: The research developed a physics-based model for radiant ceiling cooling systems and applied model predictive control to improve zone air temperature control, achieving better thermal comfort and energy efficiency. By simplifying the system model and utilizing advanced control strategies, the proposed approach demonstrated significant potential for enhanced performance compared to traditional control methods.
BUILDING AND ENVIRONMENT
(2021)
Article
Construction & Building Technology
Alo Mikola, Anti Hamburg, Kalle Kuusk, Targo Kalamees, Hendrik Voll, Jarek Kurnitski
Summary: This study analyzed the impact of ventilation requirements set in the conditions of a renovation grant on indoor environment through field measurements. The results showed that proper renovation measures can improve indoor air quality and air change rate. Room-based ventilation requirements, heat recovery and preheating measures, as well as inspection of design documentation ensured adequate ventilation and IAQ in the renovation process.
BUILDING AND ENVIRONMENT
(2022)
Article
Energy & Fuels
Hatef Hajian, Raimo Simson, Jarek Kurnitski
Summary: Space Heating (SH) substations in District Heating-based (DH) systems are often oversized and have high DH design flow rates due to the lack of accounting for internal and solar heat gains. A dynamic heating control algorithm and flow limiters can potentially reduce the required DH power.
Article
Construction & Building Technology
Abel Sepulveda, Francesco De Luca, Toivo Varjas, Jarek Kurnitski
Summary: This study focuses on the applicability of the European standard EN 17037:2018 in the Estonian cultural context, comparing the subjective perception of office users with the quantitative assessment defined by EN 17037:2018, finding a good agreement in terms of daylight provision and glare protection between users and the standard.
BUILDING AND ENVIRONMENT
(2022)
Article
Energy & Fuels
Andrea Ferrantelli, Jarek Kurnitski
Summary: This study tested the impact of different energy performance certificate (EPC) label classifications on building renovation progress and estimated their effects on the national building stock to achieve European climate goals. Results indicate the need for a unified strategy to promote renovation campaigns.
Article
Energy & Fuels
Paula Sankelo, Kaiser Ahmed, Alo Mikola, Jarek Kurnitski
Summary: The Finnish government launched subsidies for private homeowner energy renovations, and this study reveals that using ground-source heat pumps with additional insulation and heat recovery measures can significantly reduce energy consumption.
Article
Construction & Building Technology
Amar Aganovic, Guangyu Cao, Jarek Kurnitski, Pawel Wargocki
Summary: In this study, we improved the Wells Riley model by incorporating new data on viral load, aerosol droplet sizes, and removal mechanisms. We introduced several novel elements, including a new model for calculating respiratory fluid volume, a viral dose-based generation rate model for dehydrated droplets, a quanta-RNA relationship for various SARS-CoV-2 strains, and a method for accounting for incomplete mixing conditions. These improvements allowed for more accurate estimation of quanta emission rates and the potential impact of ventilation and removal mechanisms.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Tuule Mall Parts, Andrea Ferrantelli, Hendrik Naar, Martin Thalfeldt, Jarek Kurnitski
Summary: This study investigates the impact of increasing detail in modelling underfloor heating control on a simulated room's energy and temperature performance. Empirical models of wax motor and valve curve were developed and calibrated through experiments. The On/Off and proportional-integral (PI) control processes were implemented and tested at different levels of modelling detail. The biggest impact was found in the On/Off control dead band and PI parameters, which reduced energy use and temperature fluctuations. Modulating the PI output signal increased temperature fluctuations and space heating demand. The wax actuator had minimal impact but caused time delays and changes in mass flows.
JOURNAL OF BUILDING PERFORMANCE SIMULATION
(2023)
Article
Construction & Building Technology
Jarek Kurnitski, Martin Kiil, Alo Mikola, Karl-Villem Vosa, Amar Aganovic, Peter Schild, Olli Seppanen
Summary: Ventilation, air filtration and disinfection are found to be the main measures to control airborne respiratory infection transmission in shared indoor spaces. A new infection risk-based ventilation design method is proposed, which includes explicit target ventilation rate equations, implementation of pre-symptomatic period infection risk control, application of point source ventilation effectiveness, and measurement method for ventilation effectiveness. Results show that existing ventilation is enough in classrooms and offices, but higher ventilation is needed in meeting rooms, restaurants, and gyms.
ENERGY AND BUILDINGS
(2023)
Article
Materials Science, Multidisciplinary
Martin Timusk, Janis Locs, Triin Kangur, Aarne Kasikov, Jarek Kurnitski, Andris Sutka
Summary: A concept of preparing thermally responsive hydrogels with rapid and reversible light scattering switching is presented. The material exhibits a luminous transmittance of over 95% and solar energy modulation of 59.91%, and the transition temperature can be chosen in a wide range by adjusting the pH and additives in the hydrogel solution. The unique thin layer on the surface, scalability to large surface areas, and robust and fast response make this material highly potential for smart window technology applications.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Computer Science, Information Systems
Andrea Ferrantelli, Juri Belikov, Eduard Petlenkov, Martin Thalfeldt, Jarek Kurnitski
Summary: Evaluating the energy performance of existing buildings is crucial for improving the efficiency and resilience of the building stock. This study analyzed an EPC national database from Estonia to assess the readiness of the building stock and predict future trends. The findings indicate that all new and renovated buildings are estimated to become zero-energy buildings by 2050, with varying results for different building types and the impact of the COVID-19 pandemic.
