• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.445-450
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• 2012

At the limited space, the air conditioning may have difficult to control temperature or humidity for home use. Nowdays, the people reponse to temperature or humidity sensitively. This becomes the Indoor Air Quality (IAQ) is an important factor for comfortably. Heat recovery ventilator (HRV) is used for the solution of inconsistency between IAQ and power-saving. Also, the thermoelectric element is applied to HRV and compared with temperature efficiency and verifying the capacity of the system. To improve the temperature efficiency a single motor and thermoelectric element with the conductive guide vane is experimented. The results shows that it can save 23 W by using the single motor. The developed system of 250 CMH capacities with the thermoelectric element reveals the temperature efficiency improvement of 4.01% in cooling period and 2.98% in heating period compared to the conventional system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.73-77
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• 2019

In this paper, the heat pump system was designed using heat absorption of the refrigerant or condensation heat. The cooperation system has been developed to pass a heat source of low temperature to a high temperature or to pass the heat source of high temperature to a low temperature. Heat pump for using the valve as a function of switching a condenser and an evaporator in a refrigerating cycle. As a result, heat pump system was developed by air source method. Therefore cooperating system for energy saving to solve at the same time as the cooling and heating by system of one was equipped.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.31 no.3
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• pp.53-58
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• 2002

대부분의 가정용 냉난방겸용 공기조화기(히트펌프)는 실외온도가 $5^{\circ}C$ 이하이고, 습도가 높은 저온고습조건에서 난방운전을 하면 열교환기 표변에 서리가 발생하고, 이로 인해 시스템의 성능이 떨어지게 된다. 이를 방지하기 위하여 어느 일정 조건이나 시간이 되면 히트펌프는 제상운전을 하게 되는데, 보통의 가정용 히트펌프의 경우 난방운전도중에 사이클을 냉방운전으로 전환하여 실외 열교환기의 온도를 높여 줌으로써 제상을 하는 방식 (Cycle reversing method)을 사용하고 있다. 이 방식은 부가적인 제상회로플 구성하 거나 히터를 첨가하는 등의 재료비 증가 없이 제상을 수행한다는 장점이 있으나, 시스템의 에너지 효율 측면에서 불리할 뿐만 아니라, 소비자의 입장에서 보면 제상운전이 진행되는동안에 따뜻한 바람이 공급되지 않아 쾌적한 공조를 제공받지 못한다는 단점이 있다. 본 자료에서는 먼저 제상방석에 관하여 그 종류와 특정을 알아보고, 최근에 진행되고 있는 착상 지연기술 중 어큐물레이터 내에 히터를 설치하는 방식(Viung C. Mei, et al., 2002, ASHRAE TRANSSACTIONS, V 108, Pt. 1)에 대하여 소개하고자 한다.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.525-530
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• 2008

In the present study, the cooling performances of the air-conditioner applied the fin-tube and aluminum PF heat exchangers have been experimentally investigated by using the calorimeter. The experiment is carried out in the conditions of the standard temperature and the low temperature. Fin type of PF heat exchanger is a triangler and squarer form. PF heat exchanger has smaller refrigerant weight and larger capacity and COP han the fin-tube heat exchanger. The performance of PF-2 heat exchanger with the squarer in is more excellent than that of PF-1 heat exchanger with the triangler fin. The high pressure of PF heat exchanger decreases about 7%, compared to the fin-tube heat exchanger. Also, CSPF of the fin-tube and PF heat exchanger is evaluated.

• KIEAE Journal
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• v.16 no.6
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• pp.123-128
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• 2016

Purpose: In order to save the energy consumption of buildings, buildings have been constructed with high performance insulation or airtightness. However, high performance insulation or air tightness has led to a poor indoor air quality. Therefore, HRV(Heat Recovery Ventilator) has received attention to save the energy consumption and insure a good air quality. Because existing research is almost about the performance of HRV in residential buildings, This study analyzed the effect of HRV on cooling energy consumption in commercial office building. Method: This study was proceeded at commercial office building in In-cheon. In order to evaluate the energy consumption of HRV, this study proposed two methods: estimating energy consumption of the room installed AHU(Air Handling Unit) system; estimating energy consumption of the room installed HRV system. Therefore, comparison of two methods was proceeded to evaluate energy performance of each method. Result: As the result of comparison between rooms installed AHU and HRV, the experiment showed that energy consumption of the room installed HRV system is about 22% less than the room of AHU system. This conclusion is considered because the room installed HRV system have maintained temperature well at set point temperature $26^{\circ}C$.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.2
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• pp.37-42
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• 2011

Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional Cooling + reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 50% less equivalent energy than the conventional system. The on-site performance test of a prototype shows that the coefficient of performance(COP) of the DOA system is 37% higher than the conventional system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.10
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• pp.802-808
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• 2003

The air-side particulate fouling of the HVAC heat exchangers degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. The purpose of this study is to investigate the fouling characteristics using accelerated particle loading system. The fouling characteristics are analyzed as functions of a dust concentration, a face velocity and a wet or dry surface condition. The pressure drop increases with increasing test operation and reaches constant asymptotic level. For the saturated condition due to particle loading, the pressure drop across the slitted finned-tube heat exchangers at the face velocity of 1 m/sec increases up to 57% and the cooling capacity decreases about 2%. The cooling capacities are not affected greatly by the presence of the fouling deposits if the thickness of the fouling deposits can not change substantially the flow pattern through the fins.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.346-351
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• 2007

Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional cooling+reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 48.8% less equivalent energy that conventional system. The on-site performance test of the prototype shows that the coefficient of performance(COP) of the DOA system is 37.4% higher than the conventional system.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.119-127
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• 2012

For the promotion of the evaporative cooling efficiency of hot air in greenhouse in summer, a fog sprayer consisted of a high volume spraying two-fluid nozzle with turbo fan and a blowing fan was set up at 2.2 m height from bottom of small glass greenhouse and tested to estimate the possibility of the greenhouse cooling. The mean droplet size and the volume sprayed by one of fog sprayer were $29{\mu}m$ and $160m{\ell}/min$. All the droplets sprayed and blown by the fog sprayer were evaporated within 2 m radius. The result from the cooling test that two sprayers set up in glass greenhouse of plane area $228m^2$ was represented lower cooling effect that the temperature and relative humidity of inside air of greenhouse were $28.8^{\circ}C$ and 87.5% when those of outside air of greenhouse were $30.2^{\circ}C$ and 81.2%. Through investigation of literatures and results of the cooling test, it was estimated that the water spraying rate of evaporative cooling of single span greenhouse with 50% light curtain and with air change rate of 1 volume/min was $10m{\ell}/min/m^2$ so that the inside air temperature may cool down $2{\sim}3^{\circ}C$ on the basis of $35^{\circ}C$ atmospheric temperature in summer of south korean area.

• Journal of Energy Engineering
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• v.15 no.3 s.47
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• pp.160-165
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• 2006

Ground source heat pump (GSHP) or geothermal heat pump systems (GHPs) are recognized to be outstanding heating and cooling systems. Most of GSHP systems installed and studied in korea are vertical GSHP systems. A horizontal GSHP system was installed in greenhouse and investigated for the performance characteristics. The results of the study showed that the heating coefficient of performance of the heat pump was 3.64 and the overall heating coefficient of performance of the system was 3.31. The pumping power was obtained as 28.0 W/kW and the required ground heat exchanger length was 53.3 m/kW of rejection heat of condenser. The heat extraction rate was, on average, 14.58 W/m of ground heat exchanger length and trench length is 27.7 m/kW of rejection heat of condenser.