VAV/BPFS(Variable-Air-Volume/Bypass Filtration System)의 실내환경 적용에 관한 연구

최성우 한국환경과학회 2003 한국환경과학회지 Vol.12 No.12

Under controlled conditions in an environmental chamber, 24 experiments were performed to compare the ability of a Variable-Air-Volume/Bypass Filtration System(VAV/BPFS) to remove indoor pollutants and to conserve energy with the ability of conventional Variable Air Volume(VAV) system. The specific conclusions of this paper were; first, the VAV/BPFS was more efficient than the VAV system in removing particulate matter, TVOC, and target VOCs. The total effective removal rate of PM for the VAV/BPFS was two times as high as that of the VAV system. The total effective removal rate of TVOC for the VAV/BPFS was 20 percent higher than that of the VAV system. Also each target VOC concentration was reduced by using the VAV/BPFS. Second, clean air delivery rate was increased by using VAV/BPFS due to additional filtration rate. Otherwise, the VAV/BPFS decreased outdoor supply air rate above 25 percent relative to the rate of VAV system. Third, total energy consumption by the VAV/BPFS was lower than that of the VAV system during the period with indoor thermal load, occupied time. The energy saving of the VAV/BPFS ranged from 11 to 16 percent. The VAV/BPFS improves indoor air quality more efficiently than the VAV system, and it reduced energy consumption. Retrofitting the VAV system with the VAV/BPFS was easy. The use of VAV/BPFS is, therefore, recommended for buildings with VAV system as well as for buildings at designing stage.

실내공기질 모델을 이용한 환기 시스템의 공기 정화 효율성 평가

최성우 한국환경보건학회 1997 한국환경보건학회지 Vol.23 No.4

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.

VAV 시스템의 현장 운전방식에 따른 에너지 성능평가

서종욱,허정호 대한설비공학회 2004 설비공학 논문집 Vol.16 No.2

The purpose of this study is to evaluate the performance of various control strategies in commercial buildings which have been operated by the variable air volume (VAV) system. Two buildings in Seoul were chosen for the field study. The one (D building) combined by LonWorks has the constant airflow of supply fan and the proportional control of VAV units (damper type). The other (S building) combined by DDC has the PI control mode of the supply fan and the floating control of VAV units (venturi type). In estimating thermal comfort and energy performance through control modes of PI, PID, and CAV in the supply fan, we could identify several energy efficient operating control strategies for the VAV system.

에너지 효율향상을 위한 VAV 시스템 선정과 적정 최소풍량에 관한 연구

김효준,정영주,서동현,조영흠 한국생활환경학회 2013 한국생활환경학회지 Vol.20 No.7

In the VAV system, proper minimum airflow is an essential factor in IAQ and energy efficiency. However,it is hard to use VAV system effectively in the domestic industry because of lack of systematic study and management. In this study, we selected the building used as office and then changed the system and minimum airflow to increasethe efficiency of VAV system. In the simulation, Energyplus was used. We set the existing system, VAV without reheatsystem+convector as CASE1, VAV with reheat system as CASE2 and a system which applied proper minimum airflowto CASE2 as CASE3. As a result, the quality of indoor air was all satisfied and total energy consumption decreasedby about 23%.

Active Chilled Beam 시스템의 요소별 에너지 성능과 실내 열쾌적 분석에 관한 연구

김철호(Chul-Ho Kim),이승언(Seung-Eon Lee),유기형(Ki-Hyung Yu),김강수(Kang-Soo Kim) 대한설비공학회 2016 대한설비공학회 학술발표대회논문집 Vol.2016 No.6

에너지 절약형 공조시스템 별 냉방 운전 특성 및 에너지 절감 효과 비교 분석

김철호(Chul Ho Kim),이승언(Seung Eon Lee),김강수(Kang Soo Kim) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.-

In this study, we conducted EnergyPlus dynamic simulation for the design and selection of energy conservational HVAC Systems. The air-conditioning systems selected for this study are CAV(Constant Air Volume), VAV(Variable Air Volume), UFAD(Under Floor Air Distribution), and Active chilled beam with DOAS(Dedicated Outdoor Air System). We analyzed indoor temperature, relative humidity, supply air flow, cooling energy and CO2 emissions for each HVAC system used during cooling season. For the same indoor setting temperature, CAV’s supply air flow was the highest, and Active chilled beam with DOAS was analyzed as being able to perform air conditioning only with minimum outdoor air volume. VAV and UFAD system operated by varying the supply air volume according to the changing indoor load. Cooling energy was reduced by about 24.8% by applying VAV compared to CAV, and by about 33.9% by applying UFAD, 39.1% by Active Chilled Beam with DOAS. CO2 emissions also showed similar savings as that of cooling energy.

VAV/BPFS 를 이용한 실내공기 오염물질의 효율적 제어

최성우 한국환경과학회 1998 한국환경과학회지 Vol.7 No.3

The oil crisis of the 1970s and the rise in oil prices motivated people to implement energy conservation strategies. Buildings were fitted with additional insulation and reduced ventilation rates. The reduction of mechanical and natural ventilation rate led to increases in indoor pollutant concentrations which resulted in increased health risks from indoor exposure to pollutants. The variable-air-volume/bypass filtration system(VAV/BPFS) is a variation of the conventional VAV systems, The VAV/BPFS is an electronically controlled system that provides cost-effective thermal comfort and acceptable indoor air quality. Under controlled conditions in a chamber, a series experiments were performed to compare the ability of a VAV/BPFS to remove indoor aerosol concentration and to reduce energy consumption with that ability of conventional VAV system. Results show that the VAV/BPFS increases the effective ventilation rate and removes indoor air pollutant, and maintains acceptable indoor air quality without sacrificing energy consumption.

Neural Network Model-Based Adaptive Control of a VAV-HVAC&R System

M. Ning,M. ZAHEERUDDIN 대한설비공학회 2019 International Journal Of Air-Conditioning and Refr Vol.27 No.1

A dynamic system model of a two-zone variable air volume heating, ventilation and air conditioning and refrigeration (VAV-HVAC&R) system is considered. The system model consists of two environmental zones, an HVAC system and a water-cooled vapor compression chiller. Five adaptive controllers were designed to achieve good tracking control of set points of zone air temperatures, discharge air temperature, chilled water supply temperature and static pressure of the VAV-HVAC&R system. The PI controller gains were updated online using adaptive neural networks and an auto-tuning algorithm. Simulation results show that adaptive PI control gave faster response and less overshoot compared to conventional constant gain PI control. The control responses tracked set-points closely and remained stable over a typical day simulation of building operation under variable load conditions.

Analysis of Supply Airflow Control by a Stratified Thermal Model in a VAV System

Kim, Seo-Young,Moon, Jeong-Woo,Cho, Hyung-Hee The Society of Air-Conditioning and Refrigerating 2001 International Journal Of Air-Conditioning and Refr Vol.9 No.3

The present study concerns the numerical simulation of a supply airflow control in a variable air volume (VAY) system. A stratified thermal model (multi-zone model) is suggested to predict a local thermal response of an air-conditioned space. The effects of various thermal parameters such as the cooling system capacity, the thermal mass of an air-conditioned space, the time delay of thermal effect, and the building envelope heat transmission are investigated. Further, the influence of control parameters such as the supply air temperature, the PI control factor and the thermostat location on a VAV system is quantitatively delineated. The results obtained show that the previous homogeneous lumped thermal model (single zone model) may overestimate the time taken to the set point temperature. It is also found that there exist the appropriate ranges of the control parameters for the optimal airflow control of the VAV system.

Automated fault diagnosis method for a Variable Air Volume Air Handling Unit

Dong-Won Han,Young-Soo Chang 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Automated control methods in building HVAC systems have been widely applied. It is known that poorly maintained, degraded, and improperly controlled equipment wastes 15% to 30% of energy used in commercialbuildings. So, we need to detect and cope with abnormal event of target system using intelligent control system. The expert rules were developed for application to single-duct variable air volume or constant air volume air handling unit.Expert rules are composed of 28 rules using only a small number of temperatures and control signals. If any one of rules is satisfied, a fault is indicated. In this study, we tested the performance of FDD method by expert rule using simulation data under single fault and multiple faults cases. Test of the expert rule set was performed using no-fault and faulty data produced by a simulation of a three-zone building conditioned with a VAV AHU. The simulations were carried out using summer season weather data in Seoul during the occupied period under no-fault and faulty conditions. FDD method using expert rules was found to indicate each fault accurately under single fault and multiple faults