BADA

In this paper a new methodology is presented to determine airtightness of buildings. The common method for airtightness testing is through fan pressurization with a blower door test. The new methodology also uses fan pressurization. Instead of an external fan, it uses the building fan system to pressurize the building.  

Nowadays the improvement of building airtightness is an essential condition to achieve high energy performance of buildings. Therefore, there is a need to precisely describe and quantify buildings infiltrations. 

The steady pressurisation method measures the building leakage in a range of high pressures, typically 10-60 Pa. It is implemented by creating a steady pressure difference across the building envelope and measuring the corresponding airflow exchange rate between the indoor and outdoor simultaneously. This method has been widely used and accepted as the standard test for demonstrating building air-tightness compliance. Conversely, the novel pulse technique, has been developed to measure the building air leakage at low pressures typically in the range of 1-10 Pa.

The air tightness of eight apartment buildings containing six to eleven units each on three or four floors has been tested with and without guard-zone pressure, i.e. with and without consideration of internal leakages. The layouts of these buildings varied: two of them had no central stairwell, in two other buildings, only some of the apartments were connected to the central stairwell, and the third type had all apartments connected to a central stairwell.   During these tests, two to eight BlowerDoor systems were used simultaneously to create guard-zone pressure conditions.  

The AcouReVe Project aimed to improve the knowledge and the quality of acoustic calculation in ventilation ductworks. Such calculations are based on simplified models and the main issue is the input data. For each component of the ductwork, acoustic insertion loss and/or sound generation due to air velocity has to be known. Some components are well described by manufacturers, such as terminal devices, silencers, but others are not known. Sometimes, literature exists and can help to assess the input data, but the values may be out of date or no longer reflect current practices.

In a sealed building with tight facades, conditions for a good indoor air quality and comfortable conditions must be guaranteed all the time especially for employees. This paper deals with the case of a specific retrofitted building without any openings that immediately shows many difficulties to maintain good indoor air quality in some parts of the occupied volume. An assessment of ductwork and HVAC system performance was first realized, conducted by the SNIA (National Airport Engineering Service).

Noise remains a major concern for building occupants, both in their home and workplace. Ventilation system is one of the noise sources in buildings. Usually, the main issue is the resulting noise level in the room. It is generated by the fan and the ductwork components, travels inside ducts, and is then radiated into the room by air diffusers, air inlets, and air outlets. But ducts also go through other indoor spaces. Airborne noise will pass through the duct wall and radiate in the surrounding space. This can be an issue for occupants. 

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.

This paper presents the results of a series of 30 fan pressurization tests in reproducibility conditions performed within a period of 10 days in October 2017. The tested unit is a newly constructed unoccupied apartment in Brussels. These results make possible to compare different regression methods and evaluate the impact of pressure stations chosen for these regressions.

The air infiltration of a building, which fundamentally depends on its airtightness, can be a significant contributor to its heat loss.  It can also be affected by other factors such as external terrain, leakage distribution, sheltering factor and environmental conditions. The infiltration rate of a detached UK house was monitored for 2 months in early 2018 using constant concentration and decay tracer gas methods under various temperature and wind conditions.