| Project/Area Number |
13650656
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Architectural environment/equipment
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| Research Institution | Osaka City University |
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Principal Investigator |
NISHIOKA Toshiaki Osaka City University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (00254384)
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| Co-Investigator(Kenkyū-buntansha) |
OKURA Ryozi Osaka City University, Graduate School of Engineering, Assistant Researcher, 大学院・工学研究科, 助手 (10047392)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Method for Air-tightness / Amount of Cracks / Equation of the State / Impulse Pressurization / Balance of Mass / Equivalent Rate of Cracks / Alterative Pressure Method / Constant Pressure Method |
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| Research Abstract |
The new method for measuring the air-tightness of the building envelopes were tested theoretically and experimentally. In the method alterative pressure particularly impulse one was applied.
Pressure changes in a chamber were expressed with the theoretical equation which were derived from the equations of mass balance and of the state of the air in the chamber. This pressure change, differential equation includes the parameters of the air leakage, but can not be solved analytically for it's non-linearity. When there is no air source in the chamber, this differential equation can predicted the decay of pressure analytically. The procedure calculating the leakage parameters numerically by fitting measured pressure decay to the theoretical equation was provided.
A test chamber and a monitorial device of airflow volume were made to conduct the measurement of the air leakage of cracks which shape and size were known. Both the constant pressure method and the alterative ones were tested. The p
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ressure in the chamber into which some amount of air is pushed is by a fan or by a high pressure cylinder is raised to the level several hundred Pascal higher than outside and suddenly the air is stopped to supply. The former is said the step-down method and the latter impulse one. The experimental results given from the constant pressure method show that the equivalent areas of the cracks agree very well with real ones over wide range in the crack size. That of the alterative ones indicates that the agreement between the equivalent areas and the real ones is very well for smaller cracks but not for lager ones. The reason for this is that the larger the crack is, the steeper the pressure drop is and the precise, numerical simulation of the rapid decay is very difficult.
Impulsive pressurization method(IPM) by a high pressure cylinder is very convenient to measure the air leakage of the real building envelope without a supply fan and duct system. There needs no arrangement to apply, IPM is the excellent method for the airtight buildings, but not for loose ones. The experiments for smaller cracks were continued and the limits within which IPM is restricted to be apply were found. Less
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