• Title/Summary/Keyword: Indoor Air Temperature

Search Result 667, Processing Time 0.03 seconds

Effectiveness of Photocatalytic Techniques for Disinfection of Indoor Bioaerosols (실내 미생물 입자 살균을 위한 광촉매 기술의 효율)

  • Shin, Seoung-Ho;Kim, Mo-Geun;Jo, Wan-Kuen
    • Journal of Environmental Science International
    • /
    • v.16 no.7
    • /
    • pp.785-791
    • /
    • 2007
  • The current study evaluated the technical feasibility of the application of titanium dioxide ($TiO_{2}$) photo-catalytic air cleaners for the disinfection of bioaerosols present in indoor air. The evaluation included both laboratory and field tests and the tests of hydraulic diameter (HD) and lamp type (LT). Disinfection efficiency of photocatalytic oxidation (PCO) technique was estimated by survival ratio of bacteria or fungi calculated from the number of viable cells which form colonies on the nutrient agar plates. It was suggested that the reactor coating with $TiO_{2}$ did not enhance the adsorption of bioaerosols, and that the UV irradiation has certain extent of disinfection efficiency. The disinfection efficiency increased as HD decreased, most likely due to the decrease in the light intensity since the distance of the catalyst from the light source increased when increasing the HD. It was further suggested that the mass transfer effects were not as important as the light intensity effects on the PCO disinfection efficiency of bioaerosols. Germicidal lamp was superior to the black lamp for the disinfection of airborne bacteria and fungi, which is supported by the finding that the disinfection efficiencies were higher when the germicidal lamp was used compared to the black lamp in the laboratory test. These findings, combined with operational attributes such as a low pressure drop across the reactor and ambient temperature operation, can make the PCO reactor a possible tool in the effort to improve indoor bioaerosol levels.

Smart Home Service System Considering Indoor and Outdoor Environment and User Behavior (실내외 환경과 사용자의 행동을 고려한 스마트 홈 서비스 시스템)

  • Kim, Jae-Jung;Kim, Chang-Bok
    • Journal of Advanced Navigation Technology
    • /
    • v.23 no.5
    • /
    • pp.473-480
    • /
    • 2019
  • The smart home is a technology that can monitor and control by connecting everything to a communication network in various fields such as home appliances, energy consumers, and security devices. The Smart home is developing not only automatic control but also learning situation and user's taste and providing the result accordingly. This paper proposes a model that can provide a comfortable indoor environment control service for the user's characteristics by detecting the user's behavior as well as the automatic remote control service. The whole system consists of ESP 8266 with sensor and Wi-Fi, Firebase as a real-time database, and a smartphone application. This model is divided into functions such as learning mode when the home appliance is operated, learning control through learning results, and automatic ventilation using indoor and outdoor sensor values. The study used moving averages for temperature and humidity in the control of home appliances such as air conditioners, humidifiers and air purifiers. This system can provide higher quality service by analyzing and predicting user's characteristics through various machine learning and deep learning.

A Study on the Stabilization of a System for Big Data Transmission of Intelligent Ventilation Window based on Sensor and MCU (센서 및 MCU기반 지능형 환기창 빅데이터전송용 시스템 안정화에 관한 연구)

  • Ryoo, Hee-Soo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.16 no.3
    • /
    • pp.551-558
    • /
    • 2021
  • In this paper, we made the integrated intelligent air ventilation of the actuator module that can be remotely controlled based on IoT and sensors. we implemented a ventilation window system by configuring an algorithm design and a driving circuit to control the operation of the actuator to open and close the ventilation port based on a predetermined number of data that detects indoor gas/CO2/humidity temperature and outdoor fine dust related indoor/outdoor environment. It is difficult to store, manage, and analyze data due to the large number of sensors and conditions for the transmission data of indoor air circulation module. The remote monitoring and remote wireless control screens were constructed to automate the separation and operation conditions by extracting and managing the state. We apply MQTT to enhance big data transmission and construct the system using Rocket MQ to ensure safe transmission of operational big data against system errors.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.29 no.6
    • /
    • pp.327-340
    • /
    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

A Study on Development of Heat Supply Control Algorithm of Consumer Group Energy Apartment Building by Prediction of Heating Load (집단에너지 공동주택의 사용자 측 열부하 예측에 의한 열공급제어 알고리즘 개발에 관한 연구)

  • Byun, Jae-Ki;Lee, Kyu-Ho;Choi, Young-Don
    • Proceedings of the SAREK Conference
    • /
    • 2009.06a
    • /
    • pp.1300-1305
    • /
    • 2009
  • The energy conservation in buildings affects environmental preservation as well as economic benefits, and creates the comfortable indoor environment set for the inhabitants. Especially, apartment buildings show ever-increasing energy consumption with large-sized and high-class tendency, thus energy saving counterplans are needed. The present study is to develop an optical control algorithm by using heating load curve according to the outdoor temperature change. Heating load analysis should be performed before the present method can be applied. Dynamic heating load simulations are performed by resistance-capacitance method. Results show that heating load decrease linearly according to the increase of outdoor temperature.

  • PDF

A Study on Thermal Environment and Residents' Usage Behaviors of Cooling Devices in Apartments' Living Rooms (여름철 집합주택의 거실 온열 환경의 측정 및 거주자의 냉방기 사용행위에 관한 연구)

  • Bae, Nu-Ri;Chun, Chung-Yoon
    • Proceeding of Spring/Autumn Annual Conference of KHA
    • /
    • 2004.11a
    • /
    • pp.323-328
    • /
    • 2004
  • This study measured the thermal environment and residents' cooling behavior of the apartments' living rooms in summer in Seoul. The purpose of this study is to find out the present thermal environment of the living rooms and to find out the target figure of passive cooling system. The surveys and measurements took place in six apartments of Seoul for 60days(2004. 7. 3${\sim}$2004. 8. 31). The result were summarized as follows; The thermal environment of apartments' living rooms were almost neutral, and residents felt a little uncomfortable. Residents turned on the air conditioner at $27.31^{\circ}C$ of indoor temperature, and $28.89^{\circ}C$ of SET*. Therefore, cooling critical temperature of the passive cooling system can be figured out from this result.

  • PDF

Uncertainty Analysis of Test Method for Heat Recovery Ventilators (폐열회수 환기유닛의 인증시험 방법에 대한 오차분석)

  • Han, H.;Choo, Youn-Bok
    • Proceedings of the SAREK Conference
    • /
    • 2006.06a
    • /
    • pp.423-428
    • /
    • 2006
  • Twenty nine HRV models have been tested for last two years since the attestation system has been started by KARSE. It is the objective of the present study to analyze the performance test results. Uncertainty analysis has been conducted to find the effects of measured variables on the uncertainties of test results. The uncertainty of enthalpy is found to be affected by the uncertainty of wet bulb temperature significantly, but not by that of dry bulb temperature for the present range of parameters. The uncertainty of effective enthalpy efficiency is calculated to be 6%P for the cooling condition, and 3%P for the heating condition approximately. In order to reduce the uncertainty of the test results, the uncertainty of wet bulb temperature should be minimized and the indoor/outdoor test conditions should be modified so as to increase the enthalpy difference.

  • PDF

Numerical Analysis on the Initial Cool-down Performance Inside an Automobile for the Evaluation of Passenger's Thermal Comfort (차량 내부 탑승자의 쾌적성 평가를 위한 초기 냉방운전 성능에 대한 수치해석적 연구)

  • Kim, Yoon-Kee;Yang, Jang-Sik;Baek, Je-Hyun;Kim, Kyung-Chun;Ji, Ho-Seong
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.18 no.5
    • /
    • pp.115-123
    • /
    • 2010
  • Cool-down performance after soaking is important because it affects passenger's thermal comfort. The cooling capacity of HVAC system determines initial cool down performance in most cases, the performance is also affected by location, and shape of panel vent, indoor seat arrangement. Therefore, optimal indoor designs are required in developing a new car. In this paper, initial cool down performance is predicted by CFD(computational fluid dynamics) analysis. Experimental time-averaging temperature data are used as inlet boundary condition. For more reliable analysis, real vehicle model and human FE model are used in grid generation procedure. Thermal and aerodynamic characteristics on re-circulation cool vent mode are investigated using CFX 12.0. Thermal comfort represented by PMV(predicted mean vote) is evaluated using acquired numerical data. Temperature and velocity fields show that flow in passenger's compartment after soaking is considerably unstable at the view point of thermodynamics. Volume-averaged temperature is decreased exponentially during overall cool down process. However, temperature monitored at different 16 spots in CFX-Solver shows local variation in head, chest, knee, foot. The cooling speed at the head and chest nearby panel vent are relatively faster than at the knee and foot. Horizontal temperature contour shows asymmetric distribution because of the location of exhaust vent. By evaluating the passenger's thermal comfort, slowest cooling region is found at the driver's seat.

An Approach of Indoor thermal Environment Control and Energy Saving Using the PMV Index (PMV지표를 이용한 공동주택의 난방제어에 따른 온열환경 및 에너지소비량 시뮬레이션)

  • Seong, Nam-Chul;Yoon, Dong-Won
    • Land and Housing Review
    • /
    • v.1 no.1
    • /
    • pp.19-25
    • /
    • 2010
  • Thermal comfort provide satisfaction of thermal environment and affects productivity of occupants in residential building. However, temperature control can not provide the thermal comfort at all the time. because thermal comfort is influenced by many environmental variables such as temperature, relative humidity, air velocity, radiation temperature, activity level and clothing insulation. The purpose of this study is that predicted mean vote(PMV) index is used as control. And, Thermal comfort is evaluated both PMV control and temperature control by simulation. Each other cases were compared, in which set-point temperatures of $22^{\circ}C$ and $24^{\circ}C$ and, set-point PMV index through the respective heating season in the simulation. The results show that PMV control is better to maintain comfort state and save energy than temperature control.

Analysis of VOCs Infiluencing Environment Factors Using Statistics in Apartment House (통계분석을 이용한 아파트내 휘발성유기화합물의 환경인자 분석)

  • Lee, Se-Haeng;Kim, Nan-Hee;Lee, Kyoung-Soek;Park, Kang-Soo;Park, Seung-Yeol;Kim, Do-Sool;Kang, Yeong-Ju;Kim, Eun-Sun;Kim, Dong-Su
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.28 no.4
    • /
    • pp.435-445
    • /
    • 2012
  • The aim of this study is to understand the characteristics of volatile oranic compounds (VOCs) and provide information about the present Indoor Air Quality (IAQ) at residential apartments. All samples were collected in 60-min interval using the tenax absorption trap between May, 2011 and February, 2012. And the effects of environmental factors such as temperature, humidity and construction characteristics were analyzed in relation to the measured concentrations. The results of this study showed that the mean concentration of VOCs was lower than the Ministry of the Environment's standards for maintenance of indoor air quality. The correlation analysis showed that ethylbenzene and xylene (r=0.916, p<0.01), toluene and ehtylbenzene (r=0.810, p<0.01), toluene and xylene (r=0.803, p<0.01) and toluene and styrene (r=0.588, p<0.01) were significant. The result of regression analysis was found that the influenece factors associated with the concentration of VOCs were the age and location of the apartment, remodeling, the temperature and the season.