Estimation of Infiltration Rate (ACH Natural) Using Blower Door Test and Simulation

Abstract

One of the primary factors for generating heating and cooling loads in apartment houses is infiltration. However, the evaluation method for infiltration rates has not been well established for the apartment houses in Korea. The existing method measures air change per hour of a house at 50 Pa (ACH50) and divides it by the leakage–infiltration ratio, N = 20, as suggested by the Lawrence Berkeley National Laboratory (LBL). In this study, a method to evaluate the average infiltration rate of an apartment house using blower door tests and simulations is suggested. Six sets of blower door tests were conducted, and the measurement data were used to estimate the flow coefficients and pressure exponents of all infiltration routes. The values were used as the input data for EnergyPlus to calculate the natural air change per hour values (ACHn) of two households. The calculated ACHn values were compared to the ACHn values calculated using the LBL method, which is commonly used in Korea. Through this process, the limitations of applying the LBL method to calculate the ACHn values in Korea were investigated. The results show that investigating the proper leakage–infiltration ratio is required for Korea. The method suggested in this study can be used to determine the proper leakage–infiltration ratio for apartment houses.