Study on Simulation Method of Heating and Air - conditioning Energy Consumption of Residential Buildings

The heating and air conditioning energy consumption of residential buildings is influenced by the behavior of indoor living personnel.On the basis of research and analysis,two kinds of calculation modes reflecting the behavior of indoor living personnel are estimated.Under two kinds of different calculation modes,by using the building thermal environment simulation Toolkit DeST to simulate the energy consumption calculation for certain residential building in Shanghai,and the simulation results are compared with the research results.The influence of calculation mode on heating and air conditioning energy consumption of residential buildings in Shanghai is analyzed in this paper.In order to obtain the right simulation calculation method correctly reflecting the energy consumption of residential buildings.This method can be used for analysis and evaluation of heating and air conditioning energy consumption of residential buildings in Shanghai,and it can serve as instruction for right energy design of residence building.     

Effects of Operation Mode of Air Conditioning on Energy Consumption of Heating and Air Conditioning in Residential Buildings

By using the building thermal environment simulation Toolkit DeST to simulation calculation of a residential building in Shanghai,the quantitative relationship between the factors of operation mode of air conditioning affecting the energy consumption of heating and air conditioning in residential buildings has been obtained in this paper,moreover,it has come to a conclusion that the tolerable temperature is superior to control temperature of air conditioning in respect of sensitivity and the living mode of indoor personnel has certain effect on the cold energy consumption.     

Energy Consumption Features for Large scale Public Office Buildings in Greater Guangzhou, P. R. China

The annual energy consumption of representative office buildings in Guangzhou, P. R. China, was surveyed over a three year period. Among the modern office buildings surveyed, two large scale office buildings were chosen to analyze the energy consumption features and monthly energy consumption trends. Based on the actual occupied area calculation, the total annual energy consumption of the two office buildings was 149.3 kWh/m2 and 115 kWh/m2, respectively. The air conditioning energy consumption in two office buildings accounted for 49.2% and 38.5% of the total energy consumption. The research results could be used as energy consumption sub databases or references for large scale public buildings in Guangzhou due to the accurate survey technique and representativeness of the survey objects. In addition, energy consumption in these office buildings was compared with levels described in other studies. Energy saving methods are proposed for buildings located in hot summer/warm winter climate zones.     

Study on Energy - Saving Strategy and Application of Intelligent Buildings

Intelligent buildings are more convenient and comfortable, however, their energy consumption during the operation arouses a big concern in society. In this article air - conditioning system operation control is studied mainly, meanwhile, to develop a kind of energy - saving air - conditioning system and put forward a strategy of energy conservation in air - conditioning, based on the calculation of the target on - line optimized function.     

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.     

Reducing the Heating and Cooling Energy Consumption of Buildings

Abstract:This research aims at proposing measures to enhance the energy efficiency of buildings in the city of Guiyang. A computer simulation study was conducted on the basis of a building model using the DeST software package. The indoor temperature and year round heating and cooling loads were simulated. From analysis of the simulation results and taking into account the climate of Guiyang, three measures for energy efficient buildings in Guiyang are proposed. 1) Heating is a greater priority than cooling in comfortable air conditioning system design; 2) Natural ventilation should be given priority in cooling design and adjustment during seasonal transition is important to reducing energy consumption in building cooling; 3) Insulating the building envelope and lowering the glazing ratio of walls are critical for reducing energy consumption in heating buildings. Our conclusions will be useful for guiding energy efficient building design not only in Guiyang but also in mild climatic areas of P. R. China.     

Field Study on The Effects of Indoor Climate on Human Productivity and Its Economical Consequence in ofFice Buildings

In this study we carried out field studies in two office buildings in Shanghai, China to investigate the effects of indoor environmental quality on human productivity. The overall perception of occupants on indoor climate (including thermal sensation, perceived air quality, and perceived noise etc.), the influence of human factors and indoor climate factors on productivity, as well as their sick building syndrome (SBS) symptoms were assessed with subjective questionnaires. The building operating cost and employee’s salaries were record objectively. Meanwhile the indoor air temperature, humidity, air velocity, noise, concentration of formaldehyde and carbon dioxide were measured. The results indicate that about 50% occupants complained SBS symptoms when exposed to their office. Most occupants require to increase fresh air and lower the indoor noise level (especially for open-plan office), even though the physical parameters meet the requirement of standards. Thermal environment, indoor air quality and noise assessed to be the three main indoor climate factors that affect human productivity. The employee’s salaries were over 100 times of the electrical energy cost in this two buildings, which indicate great financial benefit can be achieved in China to increase occupants’ productivity by improving the indoor climate.     

Energy Consumption and Energy Use Characteristics of High-Rise Hotels: A Case Study of Xi'an,Shaanxi

In this paper, 5 high-rise hotels in Xi'an were selected for research, their energy consumption data from 2015 to 2016 were collected and analyzed, their comprehensive energy consumption per unit area was compared by using the standard coal coefficient, and their energy use characteristics and influencing factors were obtained. The test analyzed various parameters of the indoor environment and evaluated the indoor environmental quality according to the specifications and standards. Starting from the perspective of energy use systems, this paper found energy consumption priorities and problems of these hotels, and proposed feasible energy conservation measures, in a view to providing a reference for energy conservation design of high-rise hotels in Xi'an.     

Strategies for Energy-saving of Air-conditioning Systems

The building energy consumption is one of the major problems concerned by all the countries in the world. In the integral building systems,the consumption of the HVAV systems is more than 35 percent of the total building consumption. So it is important to study the strategies of energy_saving for air_conditioning systems. This paper explains some efficient and energy_saving HVAC systems, such as ice_storage air_conditioning system and underfloor air_conditioning system,and presents the strategies to accomplish the energy_saving purpose by using materials of energy_saving for enclosure structure and proper control systems. Some problems on the conservation of design and the difficulties in practical operation of energy_saving air_conditioning systems in exiting are discussed.     

Analysis and Applicati on High- Efficacy Saving Energy Technique of Central Air - Conditioning System

Aimins at the state that present central air- conditioning systems performance in high ineffective energy consumption, this paper studies the reasons of ineffective energy consumption and the key technique to solove the problem. A set of energe saving device for central air - conditioning systems is developed. A system dynamical mathematical model is established in theory, and an optimal performance pattern is fired. The central air - conditioning system can work in the optimal pattern with effective comfortability and saving energy by using. The device may save power rate to 22.6% by survey and may have broad market prospect in the southern area.     

Characteristics of energy consumption and energy efficient approaches for hotel buildings

Based on the investigation of energy consumption and air conditioning system working of 14 typical hotel buildings in Three Gorges Reservoir area cities, energy consumption characteristics of hotel buildings are analyzed. Then the use status of energy efficiency technologies of those hotel buildings is analyzed. Finally, effective energy conservation approaches for hotel buildings are brought forward and the energy-efficiency potential of variable water volume system is analyzed through testing.     

Electre Multi-Attribute Evaluation Model to the Operating Performance of Air Conditioning Systems

An ELECTRE performance evaluation model was developed to outrank the different operating conditions of air conditioning systems. Five evaluation criteria covers total energy consumption, thermal comfort PMV and PPD, indoor air quality indices such as CO2 concentration and TVOC concentration. The performance under seven different operating conditions was outranked on the TRNSYS (transient system) simulation platform. Three assignment alternatives of weight coefficients were selected to calculate the relevant credibility scores respectively. The results indicate that the proposed evaluation model can outrank the different operating conditions and select the optimum one, Moreover different weight assignments have little influence on the outranking scores. Further investigation should focus on the more evaluating criteria such as control performance and others in the comprehensive evaluation of operating conditions.     

Acceptable Temperature Range of Indoor Environment without Air Conditioning and Heating in Hot Summer and Cold Winter Zone

In order to establish “Evaluation Standard for indoor thermal environment of civil buildings”,acceptable temperature range of indoor environment without air conditioning and heating in hot summer and cold winter zone is indispensable.A two-year field measurement and questionnaire survey were carried on from 2007 to 2009 in Chongqing,which focused on office buildings and residential buildings.After the analysis of indoor and outdoor environment,occupants evaluation and thermal adaptability,a method to obtain the acceptable temperature range,was proposed.Regressing data by temperature range,and combined with human physiological and psychological experiments,the acceptable temperature range of environment without air conditioning and heating in Chongqing was determined according to outdoor air temperature changes in one year.A Comparation of methods to determine the acceptable temperature range in some international standards was discussed.     

Test and Analysis of Impact of Internal Shading of External Window on Indoor Environment

The internal shading can both impact on the sunshade and indoor daylighting, and work as an indoor heat source by absorbing heat. Presently the evaluation of overall energy efficiency of the internal shading is perceptual and qualitative. Therefore, the tests of the internal surface temperatures of house envelopes and the daylighting illuminance were carried out. It is shown that the surface temperature of interior walls with internal shading are 0.6℃～1℃ lower than those without; however,the surface temperature of internal shading is 3℃～5℃ higher than that of the interior walls. It can be seen that internal shading also forms an indoor heat source. The energy consumption of air-conditioning with internal shading decreases by 17.24% than that without, which indicates the internal shading can certainly reduce the indoor air conditioning load; however, the daylighting illuminance declines by 81%, with the results that the artificial lighting energy consumption is 1.88 times as much as that without the internal shading.     

Research on Indoor CO2 Density in Chongqing Commercial Buildings

The density of indoor CO 2 is an important value for newly_built commercial buildings. It affects comercial buildings in two aspects, one is the indoor air_quality, the other is the consumption of energy. The aim of design is to keep good indoor air_quality and using little ventilation. The authors measure a typical department store and analyze the measurement. The conclusion as well as the opinion is given, which argues for improving the efficiency of new_wind.     

Energy-Saving Performance of Thermosyphon Heat Exchanger Applied in Internet Data Center

The energy consumption of the air-conditioning system in the Internet Data Center (IDC) occupies about 40% of the total energy consumption. The thermosyphon heat exchanger using ambient energy is applied in the IDC to reduce energy consumption. By taking one IDC in Beijing as reference, the testing model is set up to experimentally analyze the heat dissipation characteristics and the energy consumption of thermosyphon heat exchanger and air-conditioning system respectively. The result indicates that the heat dissipation capacity of the building envelope takes about 19.5% of the total IDC heat load in Beijing winter conditions. The average energy consumption of the air conditioner is 3.5 kW h ~ 4 kW h per day. And the energy consumption of the thermosyphon heat exchanger takes only 41% of the air conditioner. The annual energy consumption reduces by nearly 40%. Besides, the effect of the outdoor temperature on the air conditioner energy consumption is remarkable compared with the indoor set temperature. And the air conditioner energy consumption increases by 5% ~ 6% on average when the outdoor temperature raises by 1℃.     

Investigation and Analyses of Building Energy Consumptionof Government Office Buildings in Chongqing Area

This article classifies the buildings by the time before and after energy-saving standard executed, based on the investigation of energy consumption in government office buildings of Chongqing, and analyses the energy distribution characteristics of these buildings, in which factors like the building area、air-conditioning 、management system are taken into account .Finally we acquire the energy consumption characteristics in government office buildings of Chongqing.     

Indoor thermal conditions in residential buildings during the plum rain season in East China

The indoor thermal conditions of residential buildings during the plum rain season in East China (Nanjing for example) were obtained and the accuracy of three different building energy consumption models (whole building heat, air and moisture model HAM, conduction transfer function model CTF, effective moisture penetration depth model EMPD) were analyzed. The numerical model was implemented into Matlab-Simulink and was validated using measured data from a field survey. Then the validated model was used for simulation analysis using typical weather data of plum rain season.The results from the survey showing the indoor temperature was higher than 28℃ and the indoor relative humidity was higher than 70% in most time of the plum rain season of 2013. Simulation results showed that there was not much difference when using the three models for thermal simulations, however, using CTF model for moisture simulation would result in large inaccuracy. During the plum rain season in Southeast China, when the room ventilation rate is less than 2 ACH, the moisture buffering effect of building envelope is obvious and the choice of proper hygroscopic materials can save up to 30% of building energy consumption.     

Experimental Comparison of Low-temperature Hydraulic Heating Floor and Heat Pump Air-conditioning

In this paper the low-temperature hydraulic floor heating system of a residence in Chongqing was tested. The influence of this system and the heat pump air conditioning system on indoor thermal comfort and operation cost was analyzed and compared. The effect of heat dissipation by radiation and convention of the floor was analyzed. It shows the feasibility and advantage of floor heating system in Yangtse River Region.     

Influence of Indoor Temperature and Humidity on Thermal Comfort and Energy Consumption of Air-Conditioning Systems

Taking a central air-conditioning system as an example,this paper presents the influence of indoor design temperature and relative humidity on thermal comfort and energy consumption in an office building in Guangzhou,P.R.China.The study shows that under the identical indoor thermal comfort conditions,the air-conditioning system cooling load increases with the increase of indoor temperature.Increasing the indoor temperature can not decrease energy consumption.In order to reduce the energy consumption in a central air-conditioning system meeting the required indoor thermal comfort condition,an indoor design condition with larger relative humidity and lower temperature is recommended.