Radiant Cooling and Heating Systems in Buildings

A special issue of Buildings (ISSN 2075-5309). This special issue belongs to the section "Building Energy, Physics, Environment, and Systems".

Deadline for manuscript submissions: 30 June 2024 | Viewed by 7436

Special Issue Editors

School of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, China
Interests: thermal comfort; building energy conservation; CFD; ground source heat pump; radiant floor heating/cooling system; urban thermal environment; building energy use; indoor air quality; ventilation; HVAC; outdoor thermal environment; air pollution
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Guest Editor
Department of Civil Engineering and Energy Technology, Oslo Metropolitan University, N-0130 Oslo, Norway
Interests: low-exergy building systems; indoor climate; high-performance building technologies; architectural acoustics; CFD

Special Issue Information

Dear Colleagues,

Since the 21st century, increasing attention has been given to energy savings due to emission-reduction goals. As such, HVAC technology and radiant cooling/heating air conditioning systems, representing large portions of building energy budgets, have received especially high attention. Many studies and applications have shown that radiant cooling/heating systems can provide improved thermal comfort and energy efficiency. High-temperature cooling and low-temperature heating systems use lower-grade cold and heat sources; this provides favorable conditions for the further promotion and application of radiant terminals. In addition, the cooling water temperature during summer can be increased from 7 °C to 18 °C, and the hot water temperature during winter can be reduced to 40 °C. Therefore, radiant cooling/heating systems are gaining favor and have also become the focus of study by researchers in the HVAC field. However, there are some disadvantages, such as high initial cost, inability to dehumidify the air, the possibility of water vapor condensation adjacent to the chilled radiant plates (floors, ceiling, or walls), a relatively long start-up time, as well as developing advanced operation control strategies, e.g., model predictive control. Therefore, this Special Issue aims to gather significant research contributions focusing on and linking both practical applications and scientific research on existing and new methods for radiant cooling and heating systems. We welcome all types of articles reporting original, pioneering research with experimental, theoretical, and numerical findings revealing pertinent aspects of radiant cooling and heating system in buildings. Topics of interest for publication include, but are not limited to:

  • Artificial intelligence methods for prediction the cooling/heating load;
  • Existing and new statistical methods to handle radiant systems;
  • Advanced building performance analyses for radiant systems;
  • Thermal comfort evaluation for radiant asymmetry;
  • Coupled operation issues between radiant cooling/heating and ventilation systems;
  • Condensation risk analyses on radiant cooling surfaces;
  • Energy efficiency for thermo-active building systems;
  • Assessment and optimization of the operation control strategy;
  • Renewable energy utilization in buildings for radiant systems.

Dr. Jiying Liu
Prof. Dr. Moon Keun Kim
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Buildings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • radiant cooling system
  • radiant heating system
  • thermo-active building systems (TABS)
  • thermal comfort
  • ventilation
  • HVAC system
  • energy efficiency
  • energy consumption
  • artificial intelligence
  • building performance simulation
  • control strategy
  • condensation prevention
  • dehumidification
  • data mining method

Published Papers (7 papers)

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Research

28 pages, 8955 KiB  
Article
The Mathematical Modeling and Performance of Sky Radiative Coolers
by Zhaoyi Zhuang, Xuebin Yang, Kun Xie, Mengyan Tang, Yanbiao Xu and Xianye Ben
Buildings 2023, 13(12), 2972; https://doi.org/10.3390/buildings13122972 - 28 Nov 2023
Viewed by 681
Abstract
Sky radiative cooling is a kind of passive cooling technology that uses the “atmospheric window” to emit the object’s own heat to the low temperature of outer space; this technology has low energy consumption, no pollution, and other useful characteristics, so in recent [...] Read more.
Sky radiative cooling is a kind of passive cooling technology that uses the “atmospheric window” to emit the object’s own heat to the low temperature of outer space; this technology has low energy consumption, no pollution, and other useful characteristics, so in recent years it has attracted widespread attention. The cooling effect of the sky radiative cooler is mainly affected by the constantly changing outdoor ambient temperature. In addition, the structure of the radiative cooler itself also means that its radiative cooling power undergoes obvious changes. Here, we utilized COMSOL simulation software to establish a numerical heat transfer model for radiative cooling, aimed at investigating the influencing factors on the sky radiative cooler and methods to enhance the structure of the radiative cooling. This study discusses outdoor ambient wind speed, the inlet flow rate of the cooler, installation angle of the cooler, and different cooler structures. Based on simulation results, it is observed that, for varying wind speeds, when the ambient radiation temperature is higher than the surface temperature of the cooler, a larger ambient wind speed leads to a poorer refrigeration effect. The maximum temperature difference in surface temperature at wind speeds of 0 m/s and 4 m/s is 0.59 °C. When the ambient temperature is lower than the surface temperature of the cooler, a smaller wind speed results in a greater net refrigeration power. The maximum temperature difference in this scenario is 0.32 °C. The net refrigeration power of the radiative cooler increases with an increase in water flow rate. As the water flow rate increases from 0 L/min to 5 L/min, the net refrigeration power increases from 25 W/m2 to 200 W/m2 and gradually stabilizes. Considering the radiative impact of the cooler on the surrounding environment, as the installation angle increases from 0° to 90°, the surface temperature of the cooler first increases and then decreases, reaching its highest temperature of 29.26 °C at 45°. The surface temperature of the cooler varies with the thickness of the air sandwich, increasing from 1 cm to 12 cm, and then decreasing. The lowest temperature of 23.4 °C is achieved at a thickness of 8 cm. The increase in the fin structure on the surface of the radiative cooler leads to a decrease in its refrigeration performance, and the difference between the inlet and outlet temperatures of the radiative cooler with a flat plate structure is always greater than that of the finned plate, and the difference in the average radiance is 23.52 W/m2. Finally, the energy-saving effect of the sky radiative cooling composite system is analyzed. Taking a typical small office building as an example, an energy consumption analysis model is set up, and the energy consumption of the composite system is simulated in four cities with different climates, using EnergyPlus software (version 8.6); the system’s power consumption is the largest in hot and humid climates. Compared with the traditional vapor-compression refrigeration system, the composite system reduces air conditioning power consumption by 25.7%, 32.5%, 37.1%, and 44.8% in Guangzhou, Shanghai, Jinan, and Shenyang, respectively. The main innovations of this paper include analyzing and studying the influence of the tilt angle change of the radiative plate on the refrigeration performance of the cooler and the relationship between the surrounding buildings, adding air sandwiches and ribs to the radiative cooler to analyze the influence of convective heat transfer on the refrigeration effect, which plays a guiding role in the design and research of the sky radiative cooler. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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27 pages, 13606 KiB  
Article
A Comparative Analysis of a Radiation-Cooling-Plate-Coupled Adhesion-Jet Air Conditioning System in Different Positions
by Zhaoyi Zhuang, Yang Chen, Chaoqun Lv, Jin Zhao, Xianye Ben and Shangyue Li
Buildings 2023, 13(10), 2628; https://doi.org/10.3390/buildings13102628 - 18 Oct 2023
Viewed by 631
Abstract
Compared with the traditional radiant cooling combined with a displacement ventilation air conditioning system, an air conditioning system of radiant cooling combined with an attached jet can not only effectively prevent dew on the surface of the radiant cooling plate, but also further [...] Read more.
Compared with the traditional radiant cooling combined with a displacement ventilation air conditioning system, an air conditioning system of radiant cooling combined with an attached jet can not only effectively prevent dew on the surface of the radiant cooling plate, but also further improve the cooling capacity of the radiant air conditioning system; however, most scholars have installed the radiant cooling plate on the radiant roof and the ground, and there are fewer studies on installing the radiant cooling plate on the two sides of the wall. Based on this, this paper builds an experimental system of radiant air conditioning and conducts experiments on summer working conditions in June–October to experimentally study the indoor thermal and humid environments and thermal comfort under different water supply temperatures when radiant cold panels are installed in single-side-wall, symmetrical-wall, and top-panel positions. The experimental results show that the optimal water supply temperatures of single-side-wall radiation combined with an attached-jet air conditioning system, symmetrical-wall radiation combined with an attached-jet air conditioning system, and roof radiation combined with an attached-jet air conditioning system are 18 °C, 22 °C, and 16 °C, respectively, and at the same time, the temperatures of the human body’s working area under the above water supply temperatures are 26 °C, 26.3 °C, and 26.4 °C, respectively. The average humidities in the working area are 58%, 53%, and 57%, which can meet the requirements of our country’s level II comfort when the indoor heat and humidity environment is stable, the energy consumption amounts of the radiant end are 5.71 kW·h, 3.99 kW·h, and 10.81 kW·h, respectively, and the highest efficiency of cooling and dehumidification is achieved with the symmetric-wall radiation combined with the adherent-jet air conditioning system. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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26 pages, 7811 KiB  
Article
Experimental Investigation of Mean Radiant Temperature Trends for a Ground Source Heat Pump-Integrated Radiant Wall and Ceiling Heating System
by Ahmet Dogan, Nurullah Kayaci, Baris Burak Kanbur and Hakan Demir
Buildings 2023, 13(10), 2420; https://doi.org/10.3390/buildings13102420 - 22 Sep 2023
Cited by 2 | Viewed by 1037
Abstract
Mean radiant temperature (MRT) is one of the six primary factors that determine thermal comfort in a given thermal environment. In this study, the average radiant temperature was determined using a calculation method based on the surrounding surface temperatures and view factors. The [...] Read more.
Mean radiant temperature (MRT) is one of the six primary factors that determine thermal comfort in a given thermal environment. In this study, the average radiant temperature was determined using a calculation method based on the surrounding surface temperatures and view factors. The present study specifically investigated the use of calculated radiant temperature, compared to measured radiant temperature, for predicting the mean vote (PMV) and percentage of dissatisfied (PPD) comfort parameters. The method was validated by the experimental measurements via the black sphere thermometer at five different reference points in a test room, including radiant panels on the ceiling and walls. By using global thermometer measurements, the proposed approach achieved a high degree of compatibility and an accuracy of 0.17 °C, which was the difference between calculated and measured values. The results demonstrated the reliability of the procedure using view factors and surrounding surface temperatures to calculate the radiant temperature in the designated test room; here, a straightforward method for evaluating the thermal conditions of an office room and determining the optimal location of an air temperature sensor in PMV-controlled radiant systems was also proposed. This study contributes to the increasing field of research on thermal comfort and offers knowledge that is beneficial for the design and optimization of indoor environments. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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26 pages, 5664 KiB  
Article
Experimental Study of Indoor Air Distribution and Thermal Environment in a Ceiling Cooling Room with Mixing Ventilation, Underfloor Air Distribution and Stratum Ventilation
by Xiaozhou Wu, Hao Gao, Mingming Zhao, Jie Gao, Zhen Tian and Xiangli Li
Buildings 2023, 13(9), 2354; https://doi.org/10.3390/buildings13092354 - 15 Sep 2023
Viewed by 792
Abstract
A ceiling cooling system integrated with a mechanical ventilation system has been widely used in modern buildings with large sensible cooling loads due to the high thermal comfort level and large energy efficiency. However, there is a lack of systematic research on the [...] Read more.
A ceiling cooling system integrated with a mechanical ventilation system has been widely used in modern buildings with large sensible cooling loads due to the high thermal comfort level and large energy efficiency. However, there is a lack of systematic research on the influence factors such as ceiling surface temperature and cooling load on the indoor air distribution and thermal environment, and the impact of ventilation system type in the ceiling cooling room is still unclear. Therefore, this paper presented an experimental study of indoor air distribution and thermal environment in a ceiling cooling (CC) room with mixing ventilation (MV), underfloor air distribution (UFAD) and stratum ventilation (SV); the ceiling surface temperature was 17 °C–26 °C and the internal or external cooling load was 41.5 W/m2–69.5 W/m2. The results showed that the vertical air temperature difference and contaminant removal effectiveness were 0.2 °C–0.4 °C and 0.53–0.85 with CC + MV, 0 °C–1.2 °C and 0.68–1.25 with CC + UFAD and 0.3 °C–0.9 °C and 0.50–0.83 with CC + SV, and the corresponding heat removal effectiveness and air diffusion performance index were 0.96–1.11 and 96–100%, 0.9–1.5 and 57–100% and 1.11–1.34 and 71–100%, respectively. Moreover, the difference between mean radiant temperature and air temperature and the predicted mean vote of thermal sensation were from 0 °C to 0.9 °C and between 0 and 0.26 with CC + MV, from −0.1 °C to 2.2 °C and between −0.1 and 0.42 with CC + UFAD and from −0.1 °C to 0.9 °C and between −0.2 and 0.13 with CC + SV. Hence, the ventilation system type clearly affected the indoor air distribution and thermal environment in the ceiling cooling room, and the experimental results would be beneficial for the design and control of a ceiling cooling system combined with a mechanical ventilation system in practice. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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22 pages, 7838 KiB  
Article
Indoor Temperature Control of Radiant Ceiling Cooling System Based on Deep Reinforcement Learning Method
by Mingwu Tang, Xiaozhou Wu, Jianyi Xu, Jiying Liu, Zhengwei Li, Jie Gao and Zhen Tian
Buildings 2023, 13(9), 2281; https://doi.org/10.3390/buildings13092281 - 08 Sep 2023
Viewed by 1004
Abstract
The radiant ceiling cooling system is widely adopted in modern office buildings as it improves cooling source efficiency and reduces fossil fuel usage and carbon dioxide emissions by utilizing low-grade natural energy. However, the nonlinear behavior and significant inertia of the radiant ceiling [...] Read more.
The radiant ceiling cooling system is widely adopted in modern office buildings as it improves cooling source efficiency and reduces fossil fuel usage and carbon dioxide emissions by utilizing low-grade natural energy. However, the nonlinear behavior and significant inertia of the radiant ceiling cooling system pose challenges for control systems. With advancements in computer technology and artificial intelligence, the deep reinforcement learning (DRL) method shows promise in the operation and control of radiant cooling systems with large inertia. This paper compares the DRL control method with traditional control methods for radiant ceiling cooling systems in two typical office rooms across three different regions. Simulation results demonstrate that with an indoor target temperature of 26 °C and an allowable fluctuation range of ±1 °C, the DRL on–off or varied water temperature control satisfies the indoor temperature fluctuation requirements for 80% or 93–99% of the operating time, respectively. In contrast, the traditional on–off or PID variable water temperature control only meets these requirements for approximately 70% or 90–93% of the operating time. Furthermore, compared to traditional on–off control, the DRL control can save energy consumption in the radiant ceiling cooling system by 3.19% to 6.30%, and up to 10.48% compared to PID variable water temperature control. Consequently, the DRL control method exhibits superior performance in terms of minimizing indoor temperature fluctuations and reducing energy consumption in radiant ceiling cooling systems. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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19 pages, 5700 KiB  
Article
A Numerical Study on the Exergy Performance of a Hybrid Radiant Cooling System in an Office Building: Comparative Case Study and Analysis
by Jiying Liu, Meng Su, Nuodi Fu and Moon Keun Kim
Buildings 2023, 13(2), 465; https://doi.org/10.3390/buildings13020465 - 08 Feb 2023
Cited by 1 | Viewed by 1330
Abstract
This research investigated the exergy enhancement performance of a hybrid radiant cooling system adapting to a hot and humid summer conditions through comparative case studies and analyses. This study suggested three cooling systems: a general all-air system (AAS), a conventional radiant cooling system [...] Read more.
This research investigated the exergy enhancement performance of a hybrid radiant cooling system adapting to a hot and humid summer conditions through comparative case studies and analyses. This study suggested three cooling systems: a general all-air system (AAS), a conventional radiant cooling system (CRCS), and a hybrid radiant cooling system (HRCS). As a case study, an office building with cooling systems was examined in the summer season in four different cities: Beijing, Shanghai, Chengdu, and Guangzhou, China. This study utilized the building energy performance simulation program to analyze the cooling loads of office space in a building with numerical approaches. The comparison analysis using the four different weather datasets showed simple and rational exergy efficiency and the overall impact ratio. According to the results, the ambient conditions, i.e., the surrounding temperature and the humidity ratio, significantly impacted the cooling systems’ exergy efficiency ratio. On the basis of the calculated energetic and exergetic performance, the HRCS had a higher exergy efficiency and a higher overall impact ratio. The HRCS system released an additional 20–30% of cooling output, and it could adapt well in extreme hot and humid weather conditions compared to the AAS and the CRCS system. The overall cooling impact ratio of the HRCS with an airbox convector was approximately 185% higher than that of the AAS and 8.5% higher than that of the CRCS. This study can provide the design references for the hybrid radiant cooling system and other cooling systems in hot and humid summer conditions. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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16 pages, 6473 KiB  
Article
The Thermal Responses between Young Adults and Preschool Children in a Radiant Floor Heating Environment
by Dong Liu, Na Liu, Donglin Ren, Xiaozhou Wu, Jun Wang, Yabin Tian, Anjie Hu, Li Wan and Jialan Wen
Buildings 2022, 12(12), 2234; https://doi.org/10.3390/buildings12122234 - 15 Dec 2022
Cited by 1 | Viewed by 1137
Abstract
The thermal comfort of preschool children was assumed to be similar to that of young adults, which may cause inaccuracy. This study tested and analyzed the thermal response characteristics of young adults and preschool children (4–6 years old) and the differences in thermal [...] Read more.
The thermal comfort of preschool children was assumed to be similar to that of young adults, which may cause inaccuracy. This study tested and analyzed the thermal response characteristics of young adults and preschool children (4–6 years old) and the differences in thermal sensation and thermal physiology between the two groups of participants in a room with a radiant floor heating system using the difference analysis methods (the paired data t-test, the Mann–Whitney U test and the Kruskal–Wallis H test). Participants were divided into two groups, young adults and preschoolers, and were sat in each condition while wearing winter clothing with a thermal resistance of 1.02 clo. The results showed that when the indoor temperature changed, there was a significant difference in the local skin temperature of the calf between the two groups of participants (p < 0.05). Preschool children adapt to the thermal environment better than adults, and the difference in metabolic rate is one of the influencing factors. The overall thermal sensation with mean skin temperature of the different populations was linearly correlated; correlation coefficients were 0.944 and 0.932, respectively. The overall thermal sensation of the participants was linear with respect to the indoor operative temperature. Preschool children have a higher thermal sensitivity to temperature change than young adults under low-temperature radiant floor heating systems, indicating that children have different thermal awareness from adults. There were significant differences in preschoolers’ subjective assessments of thermal sensation when the predicted mean vote (PMV) model was used as the evaluation standard; the difference ranged from 0.77 to 2.33. Thus, the PMV-predicted percentage dissatisfied (PPD) model is not suitable for preschool children. Full article
(This article belongs to the Special Issue Radiant Cooling and Heating Systems in Buildings)
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