• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.16 no.12
• /
• pp.1227-1233
• /
• 2004

Air handling unit (AHU)'s air filter pressure difference is important for energy consumption and indoor air quality. Both energy Performance data and air filter differential pressure of AHU in real office buildings were monitored and analyzed to investigate quantitatively energy impact as dust buildup level on air filter grows. We also modeled and simulated CAV system using HVACSIM＋ program to examine the energy effect of dust buildup on filters. Through analysis of time series pressure drop data, the filter pressure difference rate has been increased due to cumulative supply air flow rate increase. As filter pressure drop increased to 1 inch water column, it is found that the supply air flow rate was decreased by 10%, the chilled water flow rate was increased by 5.9% and the pump energy consumption was increased to 5.9%.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.6
• /
• pp.1225-1228
• /
• 2011

This paper presents an advanced energy saving algorithm in building. It is important to aggregate a various demand side resource which is controllable on demand response environment. Previous demand side algorithm for building is restricted on peak power. In this paper, we suggest duty cycle algorithm for AHU on demand response to reduce the quantity of building power consumption. The test results show that the proposed algorithm is very effective.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.22 no.10
• /
• pp.687-696
• /
• 2010

In this study, FDD algorithm was developed using the normalized distance method and general pattern classifier method that can be applied to constant air volume air handling unit(CAV AHU) system. The simulation model using TRNSYS and EES was developed in order to obtain characteristic data of CAV AHU system under the normal and the faulty operation. Sensitivity analysis of fault detection was carried out with respect to fault progress. When differential pressure of mixed air filter increased by more than about 105 pascal, FDD algorithm was able to detect the fault. The return air temperature is very important measurement parameter controlling cooling capacity. Therefore, it is important to detect measurement error of the return air temperature. Measurement error of the return air temperature sensor can be detected at below $1.2^{\circ}C$ by FDD algorithm. FDD algorithm developed in this study was found to indicate each failure modes accurately.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.8 no.3
• /
• pp.12-18
• /
• 2012

The purpose of this study is to make an economic analysis(Life cycle cost) of selecting optimal air conditioning system for a research building which is 8 stories with a total floor area of $32,010m^2$. Energy consumptions of three proposed air-conditioning systems(Alt-1,2,3) that reflect the government green-growth policy are calculated and compared. The results show that life cycle cost of Alt-3(Ventilation DX AHU+EHP) is less than Alt-1(EHP+ventilation DX AHU) by 5.1%, and Alt-2(Absorption chiller/heater+EHP) by 34.3%. Annual energy consumption of Alt-3 is less than Alt-1 by 9.9%, and Alt-2 by 37.4%. Annual $CO_2$ emission of Alt-3 is less than Alt-1 by 9.9%, and Alt-2 by 0.2%.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.45 no.12
• /
• pp.64-68
• /
• 2016

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.128-131
• /
• 2011

Management of indoor air quality of underground subway station is an important issue. The air handling unit (AHU) installed in the underground subway station is the main facility determining the air quality of station. Especially for removing particulate matters, it is important to operate the appropriate air filter. In this study, we studied particle collection efficiency of axail-flow cyclone for subway AHU. The particle collection efficiencies of axial-flow cyclones with three different outlet shape have been evaluated.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1205-1210
• /
• 2004

The 4-20mA analog signal used in the various industrial fields to interface sensor in distributed process control has been replaced with relatively simple digital networks, called "fieldbus, and recently by Ethernet. Significant advances in Internet and computer technology have made it possible to develop an Internet based control, monitoring, and operation scheduling system for heating, ventilation and air-conditioning (HVAC) systems. The seamless integration of data networks with control networks allows access to any control point from anywhere. Field compatible field devices become so-called "smart" devices, capable of executing simple control, diagnostic and maintenance functions and providing bidirectional serial communication to higher level controller. The most important HVAC of BAS has received nationwide attention because of higher portion of more than 40% in building sector energy use and limited resources. This paper presents the Internet-based monitoring and control architecture and development of LonWorks control modules for AHU (air handling units) of HVAC in viewpoint of configuring BAS network. This article addresses issues in architecture section, electronics, embedded processors and software, and internet technologies.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.7
• /
• pp.688-696
• /
• 2000

A scheme for fault detection on the subsystem level is presented. The method uses analytical redundancy and consists in generating residuals by comparing each measurement with an estimate computed from the reference models. In this study regression neural network models are used as reference models. The regression neural network is memory-based feed forward network that provides estimates of continuous variables. The simulation result demonstrated that the proposed method can effectively detect faults in an air handling unit(AHU). The results show that the regression models are accurate and reliable estimators of the highly nonlinear and complex AHU.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.06a
• /
• pp.193-195
• /
• 2006

유비쿼터스 시스템(Ubiquitous System)이 가지는 특징인 무선 네트워크, 제한된 자원 등으로 인하여 결함이 발생할 가능성이 높다. 이런 상황에서 결함이 발생하여도 계속적으로 사용자에게 서비스를 제공하기 위해서는 결함 복구방법이 필요하며 가장 많이 쓰이는 방법으로는 마이그레이션(Migration)이 있으나 마이그레이션 자체가 가지는 오버헤드(Overhead)로 인하여 유비쿼터스 시스템에서는 사용하기 어려운 문제점을 가지고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 경량화되어 시스템에 적은 오버헤드를 가지며 빠르게 결함을 복구할 수 있는 AHU(Autonomic Healling Utilites)를 개발하였다. AHU는 AHUServer, AHUClient, AHUBackup으로 구성되어 있으며 JDI(Java Debugging Interface)를 사용하여 사용자 어플리케이션(Application)의 필요 정보만을 추출하여 저장하고 최소한의 노력으로 사용자 시스템 또는 어플리케이션에 결함이 발생하여도 사용자의 통제없이 빠른 시간내에 서비스가 중단된 시점부터 계속적으로 서비스를 제공한다.

• Proceedings of the SAREK Conference
• /
• 2005.11a
• /
• pp.241-246
• /
• 2005

The objective of this study is to develop a rule-based fault detection and diagnosis algorithm and an experimental verification using air handling unit. To develop an analytical algorithm which precisely detects a faulted component, energy equations at each control volume of AHU were applied. An experimental verification was conducted in the AHU at Green Building in KIER. In the experiment conducted in hot summer condition, the rule based FDD algorithm isolated a faulted sensor from HVAC components.