AIVC - Air Infiltration and Ventilation Centre

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air leakage

Experimental study on the measurement of Building Infiltration and Air Leakage rates (at 4 and 50 Pa) by means of Tracer Gas methods, Blower Door and the novel Pulse technique in a Detached UK Home

Air infiltration contributes to a heat loss typically representing up to one third of the heating demand of a building. The building airtightness, also quantified as air leakage, is the fundamental building property that impacts infiltration. The steady (de)pressurization method (blower door) is the widely accepted standard process for measuring building air leakage. However, this method requires the enclosure to be pressurised to a typical range of 10-60 Pa, which is not physically representative of the pressures experienced by buildings under natural conditions.

Numerical and experimental identification of factors influencing the pressure homogeneity during an airtightness test in a large building

Airtightness is the most important property of building envelopes to understand the ventilation. Airtightness refers to the flow measurement through the building envelope as a function of pressure across the building envelope. This relationship often fits to a power law, which is the most common way of expressing data. However, pressure homogeneity during airtightness tests can crop up, especially in large buildings.

Preliminary analysis results of Spanish residential air leakage database

The air leakage impact on energy performance in buildings has already been broadly studied in USA, Canada and most European countries. However, there is a lack of knowledge in Mediterranean countries regarding airtightness. An extensive study has been carried out in order to characterize the envelope of the existing housing stock in Spain. Preliminary results of more than 401 dwellings tested are shown. The sample includes different typologies, year of construction and climate zones. Blower door tests were performed and thermal imaging was used to locate leakage paths.   

Impact of airtightness on the heat demand of passive houses in central European climate

Excessive air leakage through the building envelope increases the infiltration heat loss and therefore lowers the energy efficiency. Therefore, very good airtightness is required in case of well insulated buildings equipped with a mechanical ventilation system with heat recovery (e.g. n50 < 0.6 h-1 for passive houses). Although the building industry has progressively adopted strategies to comply with such strict limits, it is still important to study how and how much the airtightness influences the energy efficiency of different types of buildings in different climatic conditions.

Air leakage variations due to changes in moisture content in wooden construction - magnitudes and consequences

The airtightness of buildings is important for several reasons, such as being a prerequisite for low-energy buildings and for a healthy indoor air quality (without i.e. mould or radon). The airtightness of buildings can vary over time and investigations are made on these variations due to moisture induced movements in wooden constructions, and subsequent consequences, using both measurements and numerical simulations.

Air leakage of defects in the vapour barrier of compact roofs

The harsh Norwegian climate requires buildings designed according to high standards. The airtightness of the building envelope is crucial to attain an energy efficient building and to avoid moisture problems. A considerable part of building defects registered in the SINTEF Building defects archive are related to compact roofs.

Methodology for the characterization of the envelope airtightness of the existing housing stock in Spain

It has already been proved that air leakage causes a great impact in the energy performance of buildings in cold climates. In recent years, many studies have been carried out in northern Europe, US and Canada. Regulations in these countries establish maximum air leakage rates for the construction of new dwellings and the refurbishment of the existing ones. However, there is a lack of knowledge relating to the housing stock in Spain.

Detailed numerical modelling of moist air flow through a complex airtightness defect

Mastering building airtightness is essential to meet the requirements of current and future building codes, not only for saving energy but also for ensuring moisture safety. Perfect airtightness is difficult to achieve: failures are often observed, due to bad design or poor workmanship. Some published investigations proved that leaking air mostly flows through porous material and thin air channels, due to material imperfections and construction tolerances.

Durable Airtightness in Single-Family Dwellings - Field Measurements and Analysis

Durability of the building envelope is important to new homes that are increasingly built with improved levels of airtightness. It is also important to weatherized homes such that energy savings from retrofit measures, such as air sealing, are persistent. This paper presents a comparison of air leakage measurements collected in November 2013 through March 2014, with two sets of prior data collected between 2001-2003 from 17 new homes located near Atlanta, GA, and 17 homes near Boise, ID that were weatherized in 2007-2008.

Large buildings airtightness measurements using ventilation systems

The airtightness test of the building is one of a few building envelope measurements used in practice, which is quantitative, not just qualitative as e.g. infrared thermography. The so-called blower-door test result may be a measure of the building design and construction quality and could also be used for the energy demand for heating and cooling analyses.