住宅などの気密性能を測定する新たな方法

抄録

This paper describes a novel and simple method to evaluate the air permeability of building, which is evaluated by the air leakage area of building. The conventional measurement procedure defined in JIS A2201: 2017 requires a high power air blower, a flowmeter and a fine differential pressure sensor as equipment and requires the accurate measurement which must conduct by licensed investigators. The proposed method measures the changes in low frequency pressure by a low frequency microphone set in the building in the cases that all of the windows are closed and one of the windows is slightly open during when the automatic closer door is closing. From the pressures of the both cases, the air leakage area is estimated from the area of window opened, which is used as the area reference. The measurement principle is based on Hargen-Poiseuille's formula which treats the incompressible viscous fluid flow rather than the Bernoulli's law which treats perfect fluid which has been used as the base of the JIS method. The air leakage areas evaluated by the JIS method was 531cm², whereas those evaluated by the proposed methods ranged from 538cm² to 542cm² with average of 540cm², under the optimal window opening conditions for a real room whose directly measureable leakage area was 405cm². This novel and simple method yields the similar degree of measurement accuracy with the JIS method.