fan pressurization method

This article provides a summary of a comprehensive examination of the current ISO 9972 standard, focusing on the enhancements needed to improve its reliability and validity for airtightness tests in buildings. A working group composed of international experts has identified a list of issues warranting a potential revision of the standard. New recommendations are proposed based on research and consultation, including detailed considerations of previous guidelines and existing scientific literature.

The fan pressurization method is a common practice in many countries for measuring the air leakage of houses. The test results are sensitive to uncertainties in the measured pressures and airflows. In particular, changing wind conditions during a test result in some pressure stations having more or less uncertainty than others. Usually, it is necessary to fit the measured data to the power-law equation.

Even though air leakage assessment is key towards a better energy performance of buildings, Spain has still not established limitations regarding airtightness. National building regulations in Spain are gathered in the National Building Code (CTE), which was first released in 2006 and updated several times so far.

For approx. a year ago, the following was submitted to the Certification Committee, and no response is still seen. Especially the problem of the pressure at which Pa the measurement should start is seen as a criticism, and yet it has not been possible to find a reasonable explanation for the change.

Dear committee at ISO 9972,

I miss an explanation, of the change that came from EN 13829 to ISO 9972

Building airtightness tests have become very common in several countries, either to comply with minimum requirements of regulations or programs, or to justify input values in calculation methods. This raises increasing concerns for the reliability of those tests. Despite the extensive debates about how the building pressurization test standard ISO 9972 should address sources of uncertainties, no change has been implemented. According to the current standard, the zero-flow pressure shall not exceed 5 Pa for the test to be valid.

This paper presents airtightness data measured for about 752 units of high-rise reinforced concrete buildings (apartment buildings) that have been recently constructed within five years in Korea. Target buildings were mainly constructed by using reinforced concrete walls/floors, and dry/wet walls were installed between units. Airtightness data of residential units were analysed based on values of ACH50 and air permeability.

Reliable airtightness data is needed to calculate the estimate of air infiltration and the thermal loads for building energy efficiency and indoor comfort. While useful information on air leakage in low-rise dwellings does exist, there is little data available on dwellings in increasing high-rise residential buildings (particularly ones with central core plan). In this paper, we conducted airtightness measurement using fan pressurization method for about 350 dwellings in 4 high-rise residential buildings in Korea.