Radiant Air Conditioning System Research Articles

Numerical Evaluation of the Indoor Environment in a Room with Capillary Radiation Air Conditioning System

Numerical simulation has been conducted in a conference room with capillary radiation air conditioning system in Jinan. The influence of the different supply air speed on the indoor temperature field, velocity field, air age, PMV and PPD have been studied. It is found that the indoor thermal comfort level is the highest when supply air velocity is in the range of 1.75 to 2 m/s.

Independent Preservation Environment Control for In-situ Relics in Archaeology Museum

Archaeology museums play an especially important role in protecting unearthed cultural relics from natural weathering caused by the sun, wind and rain and for visitors to understand a certain history. Indoor microclimate conditions in archaeology museums greatly influence the protection of unearthed relics; however, many of the unearthed relics are suffering deteriorations or even ruins owing to improper indoor environment. In this research, a radiant air conditioning system is proposed to implement the local environment control for unearthed relics. The system can satisfy the specilized needs of the unearthed relics in preservation environment with very low energy consumption. Moreover, the soil-atmosphere coupling environment trends to be more balance such that the deteriorations caused by non-equilibrium can be greatly delayed.

放射空調設備とスプリンクラー設備の配管兼用システムの性能確認試験

Dual-purpose sprinkler water piping system which is combined with radiant air conditioning system has been developed. The system is applied to the high-rise office building in Tokyo and certified as the “special fire defense equipment” according to the Fire Service Act of Japan. Heat resistance test of the equipment and system operation test were carried out. As the result of the tests, it is confirmed that the system has the performance which is equivalent to the sprinkler system.

サーバ室を持つ事務所ビルのライフサイクルエネルギーマネジメントに関する研究 -その3 全空気式放射空調の快適性能検討-

サーバ室を持つ事務所ビルのライフサイクルエネルギーマネジメントに関する研究 -その3 全空気式放射空調の快適性能検討-

Performance Evaluation and Experimental Study of the Induction Radiant Air-conditioning System

In this paper the air-conditioning system which combined the inducement ventilation and radiant air-conditioning is proposed. The indoor terminal device is the induction unit which is processed to be combined with the radiant panel on which the copper pipes with rigid aluminum diffusion fins are installed. The radiant panel can be cooled and heated by both water and air. The two-stage evaporator chiller with the non-azeotropic refrigerant is utilized in the system. The experiments of performance test for the novel air type induction radiant air-conditioning system were carried out to verify the feasibility of the system. With the radiation to heat the building envelope of the laboratory, the system can form an overall uniform indoor temperature field both in the vertical direction and the horizontal direction. When the upside return air inlet which shown better performance was used, the space under height 2m had a moderate temperature difference. The system can greatly reduce the sensation of draught which reduces comfort.

Experimental Study on Solar Energy and Adsorption Radiation Air Conditioning System

This paper discusses the principles of solar adsorption refrigeration and the characteristics of air conditioning radiation, designs solar adsorbent bed with activated carbon - methanol as working pair and its accompanying condenser, evaporator, radiant cooling tubes and other equipment. Through experiments, it changes water supply by change flow rate of chilled water, in order to get chilled water supply and return water temperature and room temperature curve. To analysis COP value of system under different flow rate of chilled water, and get the optimal flow rate of chilled water supply.

Thermal Comfort Characteristics Analysis of Induced Radiation Units

Induces the operating principle of the induced radiation unit and studies the uniformity of indoor temperature distribution in the space and time, comfort and dewing condensation based on the PMV-PPD thermal comfort evaluation system. Through data collation and results analysis, obtains thermal comfort superiority and energy-saving potential of the reduced radiation air conditioning. The results show that the temperature distribution in the room stalled by the reduced radiation units is uniform, without sense of temperature difference and ventilation, providing an ultra-comfortable environment and that the indoor setting temperature can be up to 27°C on the premise of meeting comfort requirement. At the same time, air supply of low temperature can be achieved without condensation, reflecting the energy-saving potential of the system. These provide a reference for design of the induced radiation air conditioning system and further study.

Phenomenon of Radiation Asymmetry in The Capillary Plane Air-Conditioning Systems

Based on the introduction characteristics of capillary plane radiation air conditioning systems, we focuse on the analysis phenomenon of radiation asymmetry in the radiant air conditioning systems in the engineering practice , and discuss the condition that produces this phenomenon, and establish mathematical model of radiation asymmetric in the capillary plane air conditioning systems. And we work out the radiation angle coefficient between the human body and the floor, south wall, north wall, east wall , west wall in air conditioning rooms, and expound the radiation asymmetry degree in different parts of air conditioning rooms. The result is of positive significance to research capillary plane radiation air conditioning systems deeply and to improve occupant comfort .

Investigation of a novel thermoelectric radiant air-conditioning system

This paper presents a novel thermoelectric radiant air-conditioning (TE-RAC) system, which employs the thermoelectric modules as radiant panels instead of conventional hydronic panels. The novel radiant system brings a lot of benefits including Freon free, convenient installation, no complex water distribution pipes, quiet and reliable operation, etc. Switching between cooling and heating modes can be easily achieved by reversing the input current. The purpose of this study is to investigate the feasibility and performance of the novel TE-RAC system, including its cooling and heating performances, condensation risk, dynamic thermal response and inertia, and cost-effectiveness. A case study of the TE-RAC system is presented to compare the TE-RAC system with conventional air-conditioning (AC) systems and radiant air-conditioning (RAC) systems in terms of cooling and heating capacities, energy consumption and operation reliability. It is found that the COP of the TE-RAC system could be comparable to conventional RAC systems and AC systems, besides many other benefits in life-cycle performances.

Discussion on the Design of Freezing Dehumidification-Based Radiant Air-Conditioning System

For the purpose of realizing non-dewfall condition of the radiant panels, low energy consumption and nice comfort of the freezing dehumidification-based radiant air-conditioning system, the design temperature and humidity of the room were figured out according to the mean comfort index of human body during the design. And in order to lower the energy consumption, the necessity of the reasonable load allocation between the dehumidification unit and the radiant unit was discussed by means of the calculation with the quasi heat-humidity-ratio line. As a result, much more precise design parameters were acquired through the approximation calculation. And it was proven to be a good design method by applying these parameters to the design of the reading rooms of the library. In the design example of the reading room, the load ratio between the dehumidification unit and the radiant unit was 48 to 52, and the recirculation air flow rate of the dehumidification unit was not less than 36.8% of the total air rate of the room.

Experimental Investigation of Indoor Thermal Environment of Using Radiant Cooling

Capillary radiation air-conditioning is a form of high thermal comfort of new air conditioning, System's cooling capacity, surface radiation temperature and temperature distribution in air-conditioned room are important parameters to the system’s design and operation, determination and analysis of these parameters in the actual operation of capillary tube radiant air conditioning system is designed to have a practical reference value. This article is under summer conditions and through the experimental research methods, measurement and analysis the vertical, the horizontal and the wall temperature distributions of the air-conditioning room under different capillary radiation conditions, which provide reference information for the capillary tube design of the radiation air conditioning system, the selection of the operation parameters, the control of the condensation etc.

A-26 放射冷房システムの設計と評価に関する数値解析的研究 : 冷凍機の理論動カへの影響評価(学術研究)

A-26 放射冷房システムの設計と評価に関する数値解析的研究 : 冷凍機の理論動カへの影響評価(学術研究)

Effect of humidity and small air movement on thermal comfort under a radiant cooling ceiling by subjective experiments

Radiant air-conditioning systems are expected to be more comfortable and superior energy-saving systems than convective air conditioning ones generally used. There are some studies on radiant cooling systems. However, they were seldom put to practical use because of dew point problem in Japan. The objective of this study is to investigate the thermal comfort of local parts of the body and the whole body, in particular, including the effects of humidity (45% rh, 65% rh, 85% rh) and small air movements, by subjective experiments under a radiant cooling system. The experiments have been performed by using radiant cooling panels in a climate chamber. Subjects were seated on a chair under the radiant cooling panels, and voted their thermal sensation and comfortable sensation. The following results were obtained. Even in the radiant cooling system, the influence of humidity and small air movement on thermal sensation votes of the whole body could be correctly estimated by using a standard new effective temperature (SET*) within one scale error of thermal sensation. Small air movement with the radiant cooling system had a possibility of improving the comfortable sensation votes in the radiant cooling.