Application of an Air-Air Energy Exchanger in a Building HVAC System in Xiamen

2012 ◽  
Vol 170-173 ◽  
pp. 2474-2477
Author(s):  
Li Li ◽  
Qing Ling Zhang ◽  
Ya Ping Li
Keyword(s):  
Relative Humidity ◽  
Indoor Air ◽  
Air Conditioning ◽  
Living Environment ◽  
Operating Conditions ◽  
Total Heat ◽  
Sensible Heat ◽  
Hvac System ◽  
Indoor Temperature ◽  
Study Results

An air-air energy exchanger (AAEE) has been introduced in the literature as a novel energy recovery system that transfers heat and moisture between the ventilation and exhaust air. In this paper, the application of an AAEE in a HVAC system is investigated. The paper discusses the dependency of AAEE performance on ventilation air and indoor and outdoor air conditions, it describes how to control the AAEE in different operating conditions (summer and winter). The suited meteorological conditions of the AAEE in buildings are given. Based on the humidity and temperature data of the typical meteorological year in Xiamen, the temperature distribution statistics throughout the year is studied and the air enthalpy difference is calculated. Combining with the demand of the indoor air conditioning parameters, the applicable hours of different types of AAEE, such as total heat and sensible heat, in Xiamen are analyzed. It is shown that the lower we intend to get the temperature and relative humidity, the more space there will be for the AAEE to work in summer. In winter, for the sensible heat AAEE, the higher indoor temperature we design, the more hours it works, the greater space we will have for heat recovery. But for the total heat AAEE, it will be used longer as the indoor temperature and relative humidity are designed higher. The study results show that the AAEE can be energy-saving and reduce indoor air pollution of modern buildings, improve indoor work and living environment. The result can provide basic principle and referenced data for product improvement and air-conditioning system design.

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

Developing a Healthy, Comfortable and Energy-Saving Office Building

2012 ◽  
Vol 193-194 ◽  
pp. 45-50 ◽  
Author(s):  
Wen Pei Sung ◽  
Yi Rou Chi ◽  
Lin Jun Hong ◽  
Yu Kuang Zhao
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Room Temperature ◽  
Office Building ◽  
Tropical Region ◽  
High Humidity ◽  
Indoor Temperature ◽  
Office Environment ◽  
Research Show

How to maintain a comfortable indoor environment without excessively relying on mechanical HVAC (Heating, Ventilation, and Air Conditioning) is a target to be pursued for future living requirements. The results obtained in this research show that in an office environment, the room temperature monitored during winter is close to the comfortable temperature; however, the office occupants feel that a little warmer indoor temperature is comfort. During summer, the occupants prefer cooler temperature than the comfort temperature. Additionally, Taiwan is located in sub-tropical region with hot and humid summer. Even if the room temperature is maintained in a comfortable range, the occupants still feel not so comfortable because of high humidity. Hence, reducing the room temperature below 23 °C is inferred to make occupants feel comfortable. Questionnaire survey indicates that ventilation is preferred by 30.9% of the respondents for summer and 43.3% for winter as an effective method to improve the stuffy indoor air.

scholarly journals Probabilistic modeling of the indoor climates of residential buildings using EnergyPlus

2017 ◽  
Vol 41 (3) ◽  
pp. 225-246 ◽  
Author(s):  
Elizabeth Buechler ◽  
Simon Pallin ◽  
Philip Boudreaux ◽  
Michaela Stockdale
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Indoor Air ◽  
Air Conditioning ◽  
Residential Buildings ◽  
The United States ◽  
Climate Data ◽  
Indoor Climate ◽  
Oak Ridge ◽  
Simulation Engine

The indoor air temperature and relative humidity in residential buildings significantly affect material moisture durability, heating, ventilation, and air-conditioning system performance, and occupant comfort. Therefore, indoor climate data are generally required to define boundary conditions in numerical models that evaluate envelope durability and equipment performance. However, indoor climate data obtained from field studies are influenced by weather, occupant behavior, and internal loads and are generally unrepresentative of the residential building stock. Likewise, whole-building simulation models typically neglect stochastic variables and yield deterministic results that are applicable to only a single home in a specific climate. The purpose of this study was to probabilistically model homes with the simulation engine EnergyPlus to generate indoor climate data that are widely applicable to residential buildings. Monte Carlo methods were used to perform 840,000 simulations on the Oak Ridge National Laboratory supercomputer (Titan) that accounted for stochastic variation in internal loads, air tightness, home size, and thermostat set points. The Effective Moisture Penetration Depth model was used to consider the effects of moisture buffering. The effects of location and building type on indoor climate were analyzed by evaluating six building types and 14 locations across the United States. The average monthly net indoor moisture supply values were calculated for each climate zone, and the distributions of indoor air temperature and relative humidity conditions were compared with ASHRAE 160 and EN 15026 design conditions. The indoor climate data will be incorporated into an online database tool to aid the building community in designing effective heating, ventilation, and air-conditioning systems and moisture durable building envelopes.

Performance Analysis on a Solar-Driven Air-Cooled Ejector Refrigeration System for Air-Conditioning Using Ammonia as Refrigerant

2014 ◽  
Vol 501-504 ◽  
pp. 2282-2287 ◽  
Author(s):  
Yu Hang Liao ◽  
Wei Lu ◽  
Lie Pan
Keyword(s):  
Performance Analysis ◽  
Solar Irradiance ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Refrigeration System ◽  
Outdoor Temperature ◽  
Indoor Temperature ◽  
Changing Trend

The performance of a solar-driven air-cooled ejector refrigeration system using ammonia as refrigerant with rated cooling capacity of 10.5kW was analyzed for air-conditioning purpose. The cooling capacity of the proposed system increases with the rising of indoor temperature and enhancement of solar irradiance, while decreases with the rising of outdoor temperature. The COP has similar changing trend with that of the cooling capacity except that it increases rapidly with the enhancement of solar irradiance firstlyand then become stable by and large after solar irradiance exceeding a certain value. The cooling capacity is 6.3~52kW and the COP 0.06~0.11 under the normal operating conditions with indoor temperature over 27, outdoor temperature below 38°C and solar irradiance surpassing 500 W/m2. The proposed system can match the climatic conditions in air-conditioning season of Nanning, a typical city in hot summer and warm winter region.

scholarly journals Planning and Design of Low-Power-Consuming Full-Outer-Air-Intake Natural Air-Conditioning System

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Chien-Lun Weng ◽  
Lih-Jen Kau
Keyword(s):  
Air Quality ◽  
Low Power ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Ambient Air ◽  
Living Environment ◽  
Air Conditioning System ◽  
Solvent Vapor ◽  
Air Intake

A person stays indoors for about 85%∼90% time of his lifetime, and the need for a comfortable indoor environment is getting higher; thus, the air-conditioning dependency becomes intense too. Nowadays, residents focus on both the comfortable living environment and indoor air quality. A closed environment will become hazardous because of carbon dioxide released during respiration and toxic organic solvent vapor released from interior decoration. In order to improve the indoor air quality (IAQ), we must allow outer fresh air into the indoor space and release the dirty air out. But while taking in fresh air, the heat and factory/vehicle exhaust are also introduced. Indoor CO2, HCHO, and VOCs and outer dirty gas threaten human health badly. To solve this problem, we bring up an innovative low-power-consuming full-outer-air-intake natural air-conditioning system that completely separates intake and exhaust air, which is a solution for cross-contamination and makes mass/energy exchange by means of air and water. Design airflow exceeds 300∼500 CFM, steam evaporation mass rate reaches 3.13∼3.88 kg/hr, and heat exchange capacity becomes 1,855∼2,300 kcal/hr. The sensible heat effectiveness is 71%∼112%, and EER exceeds 14.05∼17.42 kcal/W·h. In addition, the system under design can be of positive or negative pressure status according to the user’s or work’s requirement. It creates a comfortable and healthy living environment by supplying clean and fresh outer ambient air with low power consumption.

Development of Mechanical Robot for Ducting Monitoring in Mechanical Ventilation and Air Conditioning (MVAC) System

2013 ◽  
Vol 315 ◽  
pp. 1002-1006 ◽  
Author(s):  
M.D. Amir Abdullah ◽  
Abdul Mutalib Leman ◽  
K.A.A. Rahman
Keyword(s):  
Mechanical Ventilation ◽  
Data Analysis ◽  
Air Quality ◽  
Relative Humidity ◽  
Indoor Air ◽  
Air Conditioning ◽  
Maintenance Activity ◽  
Duct Cleaning

ndoor Air Quality (IAQ) problem mostly comes from improper maintenance of ducting. Monitoring of ducting were not widely practices since the awareness to maintain it will need consideration of budget. This paper examines the development of mechanical robot that can moveable across ducting to monitor ducting condition. The device expected to collect data such as Temperature (°C),, Relative Humidity (RH), gas pollutant and picture inside ducting. The result from this kind of monitoring should be a guide for proper maintenance activity. It also can predict necessary time and duration for duct cleaning. In conclusion, the mechanical robot data analysis that captured from ducting will be compared to the IAQ standard to create safe indoor air to the user or building occupants.

scholarly journals Effects of Season and House Microclimate on Fungal Flora in Air and Broiler Trachea

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 459
Author(s):  
Danijela Horvatek Tomić ◽  
Ivica Ravić ◽  
Anamaria Ekert Kabalin ◽  
Matija Kovačić ◽  
Željko Gottstein ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Indoor Air ◽  
Ammonia Concentration ◽  
Airflow Rate ◽  
Fungal Flora ◽  
Poultry House ◽  
Study Results ◽  
Seasonal Impact ◽  
Microclimate Conditions

Fungi are present in abundance in poultry housing. The aim of the study was to assess the effect of season and microclimate parameters in poultry housing on fungal flora in the air and broiler trachea in commercial fattening conditions. The study was conducted in summer and winter. Study results indicated seasonal impact and association between fungal flora composition in housing air and broiler trachea. However, the total fungal count in housing air was significantly higher in summer and in broiler trachea in winter, both significantly correlated with indoor relative humidity and ammonia concentration. There was no significant correlation between outdoor and indoor air temperature, relative humidity and airflow rate, respectively. Study results suggested that environmental determination of fungi should be accompanied by their determination in broilers. In addition, seasonal impact on fungal contamination should be associated with microclimate conditions in the poultry house rather than the season itself. The fungi detected and the results obtained have implications not only for broiler health but also for the health of humans working in such environments.

scholarly journals Automatic and Noninvasive Indoor Air Quality Control in HVAC Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
M. C. Basile ◽  
V. Bruni ◽  
F. Buccolini ◽  
D. De Canditiis ◽  
S. Tagliaferri ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Ventilation System ◽  
Hvac Systems ◽  
Hvac System ◽  
Noninvasive Method ◽  
Time Table ◽  
Air Quality Control

This paper presents a methodology for assessing and monitoring the cleaning state of a heating, ventilation, and air conditioning (HVAC) system of a building. It consists of a noninvasive method for measuring the amount of dust in the whole ventilation system, that is, the set of filters and air ducts. Specifically, it defines the minimum amount of measurements, their time table, locations, and acquisition conditions. The proposed method promotes early intervention on the system and it guarantees high indoor air quality and proper HVAC working conditions. The effectiveness of the method is proved by some experimental results on different study cases.

Effect of Wind Velocity on Clothing Thermal Resistance and Indoor Comfortable Temperature Design

2011 ◽  
Vol 332-334 ◽  
pp. 1600-1603
Author(s):  
Sha Li ◽  
Rui Wang ◽  
Xiao Ming Qian ◽  
Zi Jun Zhao
Keyword(s):  
Energy Consumption ◽  
Thermal Resistance ◽  
Wind Velocity ◽  
Indoor Air ◽  
Air Conditioning ◽  
Thermal Sensation ◽  
Air Velocity ◽  
Indoor Temperature ◽  
Air Conditioning System ◽  
Current Specification

In this paper, it uses a manikin to test effect of wind velocity on the surface of clothing thermal resistance, and concludes that with the increase of wind velocity, the heat resistance of the clothing decrease rapidly. A seven-point thermal sensation scale was used to evaluate thermal sensation in Tianjin area, the result shows that the neutral temperature is 27.2 °C when the wind velocity is 0.82 m/s . Above 3.2°C is higher than the current specification recommended indoor temperature 24°C. It shows an appropriate increase indoor air velocity can improve the building comfortable temperature. Saving energy 29.7％一41.6％.So provides an effective way reducing the energy consumption of the air conditioning system.

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