scholarly journals EXPERIMENTAL ANALYSIS IN INDOOR THERMAL ENVIRONMENT IN TASK AND AMBIENT AIR-CONDITIONING SYSTEM USING STAND-ALONE PERSONAL HEAT PUMP UNIT

1994 ◽  
Vol 59 (463) ◽  
pp. 29-37 ◽  
Author(s):  
Kexin LI ◽  
Hisahiro ITO ◽  
Nobuo NAKAHARA
2012 ◽  
Vol 608-609 ◽  
pp. 1241-1245
Author(s):  
Wei Qiu ◽  
Li Zhang ◽  
Qing Rong liu

This paper analyses the energy consumption of water source heat pump, shows that the performance coefficient of water source heat pump unit is directly related to the temperature of water resources, and discusses the feasibility of central heating by recovering condensing heat of power plant using water source heat pump unit. It analyzes the energy saving benefit of water source heat pump unit is significant compared with traditional heating. Using the technology recovers waste heat of power plant, which can not only decrease the energy waste on the direct discharge of waste heat and water, but at the same time, it is a new air conditioning system without environmental pollution.


2019 ◽  
Vol 111 ◽  
pp. 01085
Author(s):  
Hiroshi Muramatsu ◽  
Tatsuo Nobe

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.


2019 ◽  
Vol 111 ◽  
pp. 02001
Author(s):  
Masanari Ukai ◽  
Tatsuo Nobe

In this study, an initial survey of clothing insulation and changes in the metabolic rate of individuals in office spaces was performed to establish the distribution of room temperatures at which individuals perceived a neutral thermal sensation. Subsequently, the indoor thermal environment in four offices was surveyed during the summer with different air-conditioning systems to determine the thermal environment stability in each case. The results revealed that for the required temperature, there was a noticeable difference between the average and most frequent values. Moreover, it was determined that the required temperature distribution is not normal, but rather, it is skewed to the low-temperature side. In addition, the radiant air-conditioning system was found to generate a narrow distribution of the equivalent temperature and hence, facilitated a more uniform thermal environment compared to a convective (multi-unit) air-conditioning system. Therefore, in buildings with convective air-conditioning systems, even if the planar average thermal environment is categorized as comfortable, it may be possible that workers who are sensitive to the cold or heat will complain of discomfort more frequently than those in buildings with radiant air-conditioning systems because the probability of workers sitting in cold- or hot-spot areas is higher in the former case.


2019 ◽  
Vol 889 ◽  
pp. 549-556
Author(s):  
Seiji Kamimura ◽  
Yoshiomi Ito

In the summer of 2014, the air-conditioning performance of four different snow-utilizing facilities in Niigata and Nagano Prefectures in Japan were evaluated. Systems with a snow storeroom, a rice depot and spa resort, showed the advantages of stable and flexible air temperature control with high deodorizing and dedusting effects. The investment will be earned back in less than 10 years. The system with a snow mound, shiitake mushroom greenhouses, showed that the annual cost is cheaper than that of the heat pump unit. A highway lavatory with daily snow delivery was not cost effective.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Xueyong Zhang ◽  
Yuanyuan Hu ◽  
Shengyuan Geng ◽  
Qianyong Hu ◽  
Huanbao Wang

Heat pump unit is a host device located in the central air-conditioning terminal, providing cold and hot water. Heat pump unit has the advantages of energy saving, environmental protection, easy maintenance, and so on. It is adopted to solve the problems of refrigeration and heating in ventilation and air conditioning from many engineering projects in China. When the equipment is turned on, however, the high noise generated by the heat pump unit has a very negative impact on the life and work of the surrounding residents. Therefore, noise reduction is needed to improve the environment quality. In this paper, the noise of the air-cooled heat pump unit of the square area in Shanghai was detected, the noise source was analyzed, and the corresponding noise reduction scheme was proposed. After the completion of the scheme, measurements indicate that A-weighted sound pressure level is less than or equal to 60 dB (A) during the day and less than or equal to 50 dB (A) at night, which meets the relevant national noise limit emission standards and conforms to the second-class quality standard of the acoustic environment.


2011 ◽  
Vol 374-377 ◽  
pp. 538-542 ◽  
Author(s):  
Zhi Jie Gao ◽  
Zhi Wei Wang ◽  
Ji Feng Zhao

A new adjustment law of supply water temperature of heat pump unit was presented by analyzing heat transfer performance and computing supply water temperature of fan coil unit (FCU) in this paper. The paper established the energy equations for air side, water side and FCU in dry and wet conditions, respectively. And the heat transfer performance of FCU was obtained by analyzing the manufacturers’ performance data. According to an actual central air-conditioning system of residential buildings, we calculated the daily inlet water temperature of FCU and proposed the adjustment law for supply water temperature. The results show that the supply water temperature of cooling design day is 9.3°C, the daily supply water temperature of cooling season is higher than 7°C; the supply water temperature of heating design day is 36.4°C, the highest in heating season is 38.5°C, which is below the rated supply water temperature of heat pump unit, 45°C.


Author(s):  
Bing Wei ◽  
Huayi Yang

Nowadays the energy crisis has been more and more severe all over the world. In China there is enormous energy source, but due to the large number of population, the average possession of the total energy is lower, and the energy supply is relatively less. Enormous energy consumption of air conditioning systems in the residential buildings makes the energy conservation more important. The residential central air conditioning systems are being widely used due to its advantages of easy control and low operating cost. But there are still many problems to be resolved, of which the energy consumption of the residential central air-conditioning systems is a hot issue. The main cold and heat sources for residential central air conditioning systems are air-cooled heat pump unit, household gas air conditioning unit, air-cooled chiller unit/gas-fired boiler and water loop heat pump unit. The terminal facilities suited for the anterior three units are the fan coil units, and the terminal of the last water loop heat pump unit is normally indoor unit. The combined utilization of the heat and cold source units with their terminal units keep the indoor environment in desired state all the year. In this paper, based on an actual example, the basic principles of four systems mentioned above are outlined and analyzed, and four schemes are compared. By using the method of equivalent weight full load operation time, the annual energy consumptions of the four schemes are calculated and analyzed. Comparing the annual primary energy consumption of four schemes, the following conclusions can be drawn: in the case studied, the energy consumption of the household gas-fired air conditioning unit with fan coil system is the maximum, the consumption of the air-cooled chiller unit/gas-fired boiler with fan coil system is the next, then is the air-cooled heat pump with fan coil system, and that of the water loop heat pump system is the minimum. It can be observed that the water loop heat pump system is the optimal one and is the best on energy conservation. Through the study of this paper, the minimum energy consumption system is chosen so as to give the references for the energy savings of air-conditioning systems in the practice.


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