공기질 지표를 고려한 외기냉방운전의 실내 공기질 개선 효과 분석

Abstract

The object in this paper is to determine the relation between an air-side economizer and indoor air quality (IAQ). An air-side economizer, which uses outdoor air for cooling, changes the IAQ in accordance with the outside air quality and can significantly affect the occupants’ health, leading to respiratory disease, heart disease. The Air Quality Index (AQI), developed by the US Environmental Protection Agency (US EPA), measures contaminants that adversely affect the air: PM10, PM2.5, SO2, NO2, O3, and CO, it is also divided into six air quality levels. In this study, AQI was applied as a constraint when air-side economizer operated. OpenStudio, EnergyPlus and Excel were used for simulation. It dealt with no filter and rating range from MERV 8 to MERV 16. For every filter rating and no filter, the annual average PM2.5 concentration decreased by 3.2% in Seoul and 1.9% in Shanghai. Specifically, according to the Republic of Korean PM2.5 standard, total number ofminutes exceeding PM2.5 threshold was decreased to 42,819minutes from 51,434 minutes in Seoul when AQI modified economizer operated with no filter and MERV 8. In Shanghai, based on the Chinese PM2.5 standard, total number of minutes exceeding PM2.5 threshold decreased to 28,666 minutes from 34,048 minutes in MERV 9. The results confirmed that AQI modified economizer with no filter has positive effect on IAQ. Among the filters, MERV 8 and MERV 9 had the greatest reduction in Seoul and Shanghai when used with the AQI modified economizer based on the Republic of Korean and Chinese standards, respectively. The results of HVAC energy consumption simulation showed 0.80% and 0.65% increase in Seoul and Shanghai when AQI-modified economizer was operated than differential enthalpy economizer in all filter.