Air conditioner filters purify the air of indoor environments by removing air pollutants and supporting the efficiency of the unit’s cooling function. However, an air conditioner filter can become a microenvironment in which some fungi can grow as dust continues to accumulate and favorable humidity conditions are formed. Fungal growth in air conditioner filters could lead to fungal allergies or fungal diseases, in addition to emitting a foul odor. In an effort to understand what species causes this malodorous problem, we investigated the diversity of fungi found in air conditioners. Fungi were sampled from the collected air conditioner filters and grown on DG18 agar media. After purification for pure isolates, species identification was undertaken. Colony morphology was observed on PDA, MEA, CYA, and OA media. Microstructures of fruiting body, mycelia, and spores were examined using a light microscope. Molecular identification was performed by PCR and sequencing of PCR amplicons, and molecular phylogenetic analysis of sequenced DNA markers, including the Internal Transcribed Spacer (ITS), the 28S large subunit of the nuclear ribosomal RNA (LSU rDNA), the β-tubulin (BenA) gene, the Calmodulin (CaM) gene, and the DNA-directed RNA polymerase II subunit 2 (RPB2) gene. Through this identification process, we found two fungal species, Aspergillus miraensis and Dichotomopilus ramosissimus, which are unrecorded species in Korea. We will now report their morphological and molecular features.

The cooling operating characteristics of the 3 room air conditioner are experimentally investigated for the number of the indoor units (A, B, C) and the operating conditions (standard, overload) under the cooling operation. The cooling capacity and COP were calculated using a multi-type calorimeter. Also, EEV opening, compressor frequency, and superheat degree were obtained when the compressor started. From the experimental results, we can see that the performance and operation characteristics of the air conditioner depend on the indoor unit operation method. In case of simultaneous and single operation, the cooling overload performance was measured lower than the standard condition. Also, in the overload operation, the power consumption of the compressor was greatly increased and the COP was also decreased.

The air conditioner is an instrument to make a low degree fresh wind by compress a refrigerant and through the heat exchanger. As change a refrigerant of low degree and low pressure to high degree and high pressure, it is needed to the compressor. The compressor compress a refrigerant by transfer the rotational energy to reciprocating energy. The goal of this research is for easy use to failure diagnosis of an automotive compressor according to vibration characteristics of each failure types of automotive compressor. To do this, we have prepared the normal products and made some detective products which several kinds of detective types to measure and analysis of vibration characteristics. From the results, we have made a close investigation into the vibration characteristics of each kinds of detective type.

본 연구에서는 선박의 중앙집중 공조시스템에 공랭식 에어컨을 직접 설치하여 열원의 성능개선과 거주 구역별 독립 냉 난방이 가능한 개별분산 공조시스템을 하고자 하는 것이다. 연구 결과 기존의 중앙집중방식 공조시스템에 비해 열원 제어와 열효율상의 문제점을 보완함과 동시에 장치의 효율을 향상시킴을 확인하였다. 또한 동일한 조건에서 장치의 냉동능력과 성능계수는 평균 약 3 %, 23~26 % 정도 높게 나타났으며, Chilled Water Plants의 압축기 소비동력은 약 12 % 정도 낮게 나타났고, 동일한 조건에서 난방 시 소비동력은 약 33.5 % 낮게 나타났다. 따라서 공랭식 에어컨을 이용한 개별분산 공조시스템이 열원 제어뿐만 아니라 장치의 성능향상과 거주구역별 쾌적한 온 습도 환경 조성에 크게 기여하는 결과를 얻을 수 있었다.

This paper presents the detection and diagnosis of air-conditioner electromagnetic sound through noise measurements. Electromagnetic sound originating from the motor is an unpleasant source of unwanted noise that should be detected at the manufacturing stage. A detection system using sound measurements was built and a detection algorithm based on FFT analysis is presented. Sound measurements are preferable over direct vibration measurement because it is non-contact and low cost. Experimental results show that our sound measurement system can detect electromagnetic sound effectively compared to using vibration measurements.

Bioaerosols, airborne particles of biological origin, are omnipresent in the common surroundings of humans. In antimicrobial filter system, as particles or organic materials are deposited on the filter surface, the bacteria come into contact with the antimicrobial material less, and thus they can easily grow on particles or organic materials. We selected a carbon fiber ionizer which generated air ions as antimicrobial agent. Antimicrobial effect of carbon fiber ionizer on the outlet air and condensate water was tested using application of carbon fiber ionizer in a small-scale commercial air conditioner. In conclusion, the application of carbon fiber ionizer in the air conditioner showed more increasing antimicrobial efficiency.

본 연구는 에어컨의 적정냉매충전량 진단을 위한 자료를 제공하기 위하여 수행하였다. 공기 온도 33∼35℃, 습도 55∼57%RH로 조절되는 실내에서 SONATA III(Hyundai motor Co., Korea)자동차의 에어컨시스템을 대상으로 냉매충전 및 성능시험장치를 구성하고 냉매충전량 변화에 따른 냉매라인의 측정량으로 각 지점 온도와 고압 및 저압을 측정하고 분석하였다. 냉매라인의 측정온도는 압축기, 응축기, 리시버드라이어 및 증발기의 입구와 출구 파이프표면온도와 응축기와 증발기벤트 입구와 출구의 송풍공기온도이다. 이들 각 온도와 압력은 정도의 차이는 있으나 모두 냉매충전량(Wr)에 따른 영향을 받으며, 이들을 측정하여 냉매충전 정도를 진단할 수 있는 것으로 나타났다. 엔진회전속도 2,000 rpm과 1,500 rpm에 따른 각 측정량의 변화양상은 차이가 나타나지 않아 에너지사용량이 낮은 1500 rpm이 시험 회전수로 적당할 것으로 판단된다. 냉매충전량에 가장 큰 영향을 입는 측정량은 증발기벤트 입출구온도차(Td)이며, 그 다음이 냉매라인 고압측의 압력(P1)으로 나타났다. 1,500 rpm에서 Wr이 350 g까지 증가함에 따라 Td는 급격히 증가하다가 350g에서 700g까지는 12.8℃에서 16.7℃로 완만하게 증가하였고, 700g을 초과하면서 완만하게 감소하였다. P1은 Wr이 400 g까지 증가함에 따라 급격히 증가하다가 400 g에서 700 g까지는 14.3 kgf/cm2에서 16.0 kgf/cm2으로 완만하게 증가하였고 700 g을 초과하면 급격하게 상승하였다. 에어컨사용설명서에 제시된 냉매충전량이 720 g인 것을 고려하면 1,500 rpm에서 적정냉매충전량 진단은 5%오차범위에서 증발기벤트 입출구 공기온도차가 15℃, 고압측압력 15 kgf/cm2일 때로 추정된다. 에어컨상태가 정상인 진단은 Td가 12℃이상과 P1이 14 kgf/cm²에서 16 kgf/cm² 사이일 때로 판단된다.

We performed numerical analyses on the optimal discharge angle of a 4-way cassette air conditioner, which is mounted on the ceiling of the classroom, by using thermal comfort and ventilation indices. We analyzed the effective draft temperature, the local mean age and the local mean residual life time with respect to the variation of the air discharge angle of the air conditioner in all occupied zone. Air diffusion performance index, local supply effectiveness and local exhaust effectiveness were used to investigate the optimal value of air discharge angle. From the results, we found out that the optimal discharge angle of the air conditioner is about 40 degrees in the present model.

In order to develop combination air filters for air conditioners, 2 types of charging section were constructed. One was the wire-plate type and the other was the scroll type. Each charging section was combined with the same electrostatic polypropylene (PP) media. NaCl aerosol particles with geometric mean diameter of 0.05∼0.16㎛, geometric standard deviation of 1.6∼1.9 and total number concentration of 1,700∼24,000 particles/㎤ were used to determine collection efficiencies of the combination air filters for air conditioners with respect to particle size. It was shown that the scroll type combination air filter has greater collection efficiencies and lower pressure drops than the wire-plate type one does.

This study concerns with an ergonomic approach for improving the workplace of an air-conditioner factory. If work tasks and equipments do not include ergonomic principles in their design, workers may have exposure to undue physical stress, strain, and overexertion, including awkward postures, forceful exertions, repetitive motion, and heavy lifting. The purpose of this study is to improve the safety, comfort, and efficiency of the workplace. Adapting tasks, work stations, tools, and equipments to fit the worker can help reduce physical stress on a worker's body and enhance the effectiveness and efficiency of workplace.

A practical application of a fuzzy control system is described for an air-conditioning system. Air-hadling units are being widely used for improving the performance of central air-conditioning systems. The fuzzy control system has two controlled variables, temperature and humidity, and three control elements, cooling, heating, and humidification. In order to achieve high efficiency and economical control, especially in large offices and industrial buildings, two controllable parameters, temperature and humidity, must be adequately controlled by the three final controlling elements. In this paper a fuzzy control system was described for controlling air-conditioning systems efficiently and economically.