• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.9
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• pp.608-613
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• 2008

The purpose of the present paper is to investigate the effect of outdoor weather conditions on the performance of a heat recovery ventilator. Experiments have been performed by varying outdoor temperature/humidity conditions with the indoor conditions fixed at the standard conditions by KARSE. Results indicate humidity efficiency shows larger uncertainties than temperature efficiency in general. With the heat generation by an internal fan removed, the modified temperature efficiency remains almost constant regardless of the indoor-outdoor temperature difference. The enthalpy efficiency can have very large or negative values in case the outdoor conditions are in the vicinity of the indoor enthalpy line. The direction of heat flow, in such a case, can be opposite to that of moisture flow between two air streams. Discussions are included about various interesting features of the psychrometric processes taking place in a heat recovery ventilator.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.4
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• pp.165-170
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• 2016

Long-term performance of the enthalpy exchange element is a topic of current interest due to the concern of possible performance degradation over time. In this study, a 350 CMH enthalpy recovery ventilator equipped with an enthalpy exchange element was installed in an office room, and the performance has been traced over the past 5 years. The appearance, overall dimension, thermal performance, leakage ratio and anti-bacterial performance were checked annually. Results showed that the change in thermal performance (sensible, latent and enthalpy efficiency) was negligible with periodic cleaning with an air gun. However, the leakage ratio increased with time, measuring 7.3% after 5 years. Anti-bacterial test revealed that no bacteria were found during the test period. The largest change in the dimension occurred at the middle location of the element, although the change was less than 2% of the initial value.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.423-428
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• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.2
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• pp.68-73
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• 2017

Recently, energy recovery ventilators (ERVs) have been installed for energy saving in many multi-residential buildings in Korea. The performance of the heat exchanger of an ERV is analyzed in this study under specific indoor and outdoor conditions in a test-cell measurement. However, the performance of the heat exchanger varies according to the indoor and outdoor condition. In this study, the performance of energy recovery of the ventilation system was therefore analyzed in actual weather conditions using field measurement. Experiments were conducted under winter conditions in a multi-residential building for 20 days. Based on the measurement results, the characteristics of sensible heat and latent heat exchange rates were analyzed.

• Journal of Power System Engineering
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• v.21 no.1
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• pp.50-56
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• 2017

To increase the enthalpy exchange efficiency of ERV elements, the moisture exchange character must be improved. The moisture exchange efficiency depends on material characteristics. The material used for ERV is Hwang-to paper based on Han-ji which is Korean traditional paper. The paper has excellent performance in moisture exchange and heat transfer compared with polymer and other papers. To have an anti bacteria performance and to improve moisture exchange performance of Han-ji, Hwang-to is added to the Han-ji. The enthalpy exchange efficiency of the Hwang-to paper shows 5% greater than that of the conventional paper. In case of Escherichia Coli, the reduction rate of bacteria is 96.6% and in case of Pseudomonas, the reduction rate of bacteria is 97.5%. The ERV element made of Hwang-to paper has a great possibility as an ERV element.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.421-427
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• 2016

The indoor temperature of a building increases during the day due to solar radiation. This behavior is significant in school buildings that are finished with high thermal capacity materials. Moreover, in school buildings, windows cannot be opened until the class has finished owing to the security policy of schools. Consequently, classrooms maintain a high temperature throughout the morning. It is thus important to remove the indoor heat before the commencement of classes in order to reduce the cooling energy needed. The Energy Recovery Ventilator (ERV) system is currently being installed in school buildings for ventilating the classrooms. Night-purge control using ERV can be a good strategy to cool the classroom in advance of the operation of the cooling system. However, the optimal operation method of the ERV for night-purge control has not yet been reported. In this study, the effect of night-purge control with ERV in school buildings is analyzed by simulation method. The results of this study showed that the energy saving effect of night-purge control with ERV is most effective in the case of 2 hours operation prior to the commencement of the first lass and when enthalpy based outdoor air cooling is used.