The correction coefficients for the building air-conditioning load accounting for the whole building hygrothermal transfer process for major cities in China

2016 ◽  
Vol 26 (5) ◽  
pp. 642-661 ◽  
Author(s):  
Yingying Wang ◽  
Yanfeng Liu ◽  
Dengjia Wang ◽  
Jiaping Liu
Keyword(s):  
Relative Humidity ◽  
Transfer Process ◽  
Heat Load ◽  
Air Conditioning ◽  
Moisture Transfer ◽  
Moisture Flux ◽  
Heating And Cooling ◽  
Heat Transfer Theory ◽  
Building Cooling ◽  
Heating And Cooling Load

At present, the calculation software and design specifications related to building cooling and heating load are based mainly on heat transfer theory. The effect of building moisture transfer process on the air-conditioning load is rarely researched. The aim of this paper was to investigate the effect of the whole building hygrothermal transfer (WBHT) process on the indoor air temperature and relative humidity, wall inner surface temperature and moisture flux, sensible heat load, latent heat load and total air-conditioning load in different climates. A WBHT model was developed and validated by the analytic solution and experimental data. Three humidity regions in China were classified for summer and winter according to the different outdoor air relative humidity levels. The correction coefficients of air-conditioning load of major cities were obtained accounting for the WBHT process. Our results would provide a future reference for accurately calculating heating and cooling load of buildings in different climate regions.

scholarly journals Proposed Strategies for Improving Poor Hygrothermal Conditions in Museum Exhibition Rooms and Their Impact on Energy Demand

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 620 ◽  
Author(s):  
Joanna Ferdyn-Grygierek ◽  
Krzysztof Grygierek
Keyword(s):  
Relative Humidity ◽  
Energy Demand ◽  
Air Conditioning ◽  
Control Strategies ◽  
Internal Heat ◽  
Current Method ◽  
Dramatic Improvement ◽  
Precise Control ◽  
Heating And Cooling ◽  
Microclimate Conditions

In museums, poor microclimate conditions, especially large changes in relative humidity and temperature, can lead to serious deterioration of the exhibits. Properly designed heating, ventilation, and air conditioning (HVAC) systems for precise control of the air parameters are required. However, due to the financial restrictions of museums, complex air-conditioning systems are often not feasible. In this study, we tested and propose novel methods to reduce the short- and long-term fluctuations in the relative humidity in exhibition rooms of a Polish museum. The methods only include indoor temperature and ventilation airflow control strategies, without the use of (de)humidification equipment. The analysis is based on simulations using EnergyPlus software. A multi-zone thermal model of the museum building was validated and calibrated with measured data. A full calendar year was simulated for five control cases (including the current method used) and two internal heat gain schedules. The energy demand for heating and cooling for each case was calculated. The combination of temperature control and adequate ventilation using ambient airflow allows for dramatic improvement in the microclimate conditions. The proportion of the year when the instantaneous indoor relative humidity is ±5% from set point decreased from 85% to 20%. A significant effect was obtained over the summer months.

scholarly journals Review of Intelligent Control Systems for Natural Ventilation as Passive Cooling Strategy for UK Buildings and Similar Climatic Conditions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4388
Author(s):  
Esmail Mahmoudi Saber ◽  
Issa Chaer ◽  
Aaron Gillich ◽  
Bukola Grace Ekpeti
Keyword(s):  
Control Systems ◽  
Natural Ventilation ◽  
Energy Use ◽  
Integrated Control ◽  
Climatic Conditions ◽  
Effective Control ◽  
Practical Implementation ◽  
Optimal Output ◽  
Heating And Cooling ◽  
Building Cooling

Natural ventilation is gaining more attention from architects and engineers as an alternative way of cooling and ventilating indoor spaces. Based on building types, it could save between 13 and 40% of the building cooling energy use. However, this needs to be implemented and operated with a well-designed and integrated control system to avoid triggering discomfort for occupants. This paper seeks to review, discuss, and contribute to existing knowledge on the application of control systems and optimisation theories of naturally ventilated buildings to produce the best performance. The study finally presents an outstanding theoretical context and practical implementation for researchers seeking to explore the use of intelligent controls for optimal output in the pursuit to help solve intricate control problems in the building industry and suggests advanced control systems such as fuzzy logic control as an effective control strategy for an integrated control of ventilation, heating and cooling systems.

scholarly journals Comparison of Building Simulation Methods for Modeling Apartment Balconies

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3955
Author(s):  
Yonghan Ahn ◽  
Hanbyeol Jang ◽  
Junghyon Mun
Keyword(s):  
Heat Transfer ◽  
Air Temperature ◽  
Parameter Analysis ◽  
Interior Space ◽  
Heating And Cooling ◽  
Significant Difference ◽  
Calculation Results ◽  
Infiltration Parameter ◽  
The Difference ◽  
Heating And Cooling Load

The purpose of this study is to compare the load calculation results by a model using the air changes per hour (ACH) method and a model using an airflow network (AFN) and to ascertain what causes the difference between the two models. In the basic case study, the difference in the heat transfer distribution of the model in the interior space was investigated. The most significant difference between the two models is the heat transfer that results from infiltration. Parameter analysis was performed to investigate the relationship between the difference and the environmental variables. The result shows that the greater the difference is between the air temperature inside the balcony and the outdoor air temperature, and the greater the air flows from the balcony to the residential area, and the greater the heating and cooling load difference occurs. The analysis using the actual weather files of five domestic cities in South Korea rather than a virtual case shows that the differences are not so obvious when the wind blows at a constant speed throughout the year, but are dominant when the wind does not blow during the night and is stronger alongside the occurrence of sunlight during the day.

scholarly journals Optimization method of hourly heat load calculation model for heat storage air-conditioning heating system in different climate zones

2021 ◽  
pp. 014459872110052
Author(s):  
Yuechao Liu ◽  
Dong Guo ◽  
Min Zhou ◽  
Shanshan Wu ◽  
Dongmei Li
Keyword(s):  
Heat Load ◽  
Air Conditioning ◽  
Heat Storage ◽  
Heating System ◽  
Optimization Method ◽  
Calculation Model ◽  
Climate Zones ◽  
Load Calculation ◽  
Typical Day ◽  
Additional Coefficient

One optimization method of hourly heat load calculation model for heat storage air-conditioning heating system in different climate zones was proposed. A building model is initially built in six different climate zones. Subsequently, the hourly heat load and steady-state design heat load in different climate zones were analyzed. Simultaneously, the hourly heat load additional coefficient of the air-conditioning system with different heating modes on a typical day was compared. It can be found that steady-state design heat load on a typical day is mostly between the peak load and average load of the air-conditioning heating system. Simultaneously, results indicate that the hourly heat load additional coefficient in each climate zone can be fitted to different exponential functions. When the heat storage capacity of building components was changed, the maximum increase of the hourly heat load additional coefficient of the air-conditioning system with intermittent heating was 5%. Thus, the research of the optimal design of hourly heat load calculation method provides a relative reference for performance improvement of the heat storage air-conditioning heating system.

Study on the Ground-Source Heat Pump with Properties of Thermal Dynamics Used in Heating and Air Conditioning by Economic Analysis

2012 ◽  
Vol 252 ◽  
pp. 433-437
Author(s):  
Zhi Yang Yuan
Keyword(s):  
Economic Analysis ◽  
Heat Pump ◽  
Air Conditioning ◽  
Surface Soil ◽  
Ground Source Heat Pump ◽  
Thermal Dynamics ◽  
Air Conditioning System ◽  
Economic Competitiveness ◽  
Heating And Cooling ◽  
Ground Source

The ground-source heat pump is a system which takes the shallow surface soil energy as the source of heating and cooling. The temperature of ground source is relatively stable throughout the year, which makes the ground-source heat pump have the higher operation efficiency compared with the traditional air-conditioning system.Study on the ground-source heat pump with properties of thermal dynamics used in heating and air comditioning by ecomomic analysis is still an important issue. In this paper, the ground-source heat pump and the traditional heating and air-conditioning system have been compared in terms of their economic competitiveness. Firstly, it is required to compare the ground-source heat pump with the traditional heating method in terms of the heating economy. Afterwards, it is necessary to compare the ground-source heat pump with the conventional electric refrigeration in terms of the air-conditioning economy. Finally, it is needed to conduct the comprehensive and economic analysis for the ground-source heat pump and the boilers and air conditioning, which includes four programs.

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