English

We conducted observations of wind velocity profiles above a high-density area in Tokyo, Japan, using a Doppler LIDAR system. Obtained data of the exponent index for the power law, which is commonly used to describe the wind velocity profile, displayed diurnal variation, decreasing in the daytime, which is expected in unstable atmospheric conditions. This paper provides information on the uncertainty in the calculated ventilation airflow rate due to the use of a constant value for the exponent index.

The objective of this paper is to assess the impact of the envelope airtightness on airflow patterns for single detached dwellings depending on the ventilation system.

The Net Zero Energy Residential Test Facility (NZERTF) was constructed at the National Institute of Standards and Technology (NIST) to support the development and adoption of cost-effective net zero energy designs and technologies. Key design objectives included providing occupant health and comfort through adequate ventilation and reduced indoor contaminant sources.

Constructions joints occur everywhere where several construction materials meet. That’s many meters that need to be taken care off, respecting the function that the materials or the joint need to fulfill. Typically a joint filled with sealing material has to account for water tightness, or is applied for esthetical reasons. Insulating materials can also be injected for thermal or acoustical insulation. A combination of joint materials often guarantees more advanced functions, fire resistance is a typical example.

Building airtightness in Germany is on a good way. The latest survey amongst FLiB members shows the n50-values are much better than the benchmarks given in EnEV 2014 (German EPBD). For airtightness tests in 2014 the average n50-value of single-family houses is 1.1 ACH for new buildings and 1.6 ACH for refurbishments. In multi-family houses the average n50-value for new buildings is 0.9 ACH and 1.5 ACH for refurbishments.

In timber frame construction in Europe air barrier systems are typically realised at the interior side of the building envelope. Yet in some applications such as renovation projects it can be easier to provide the air barrier layer at the exterior. This way, the air barrier system – typically board materials in which the joints are sealed with tape – is exposed to outdoor weather conditions. The aim of the present article is to investigate the impact severe climatic conditions on the airtightness of typical taped joints.

Interior wooden surfaces have the capacity to buffer the maxima and minima of relative humidity (RH) indoors. Especially in high performance buildings, where high airtightness levels as well as high indoor air quality (IAQ) are required, there is great potential for energy savings by reducing the mechanical ventilation demand. The last decade, the moisture buffer phenomena has been widely researched. Relevant findings showed that the moisture buffering effect is reduced when the ventilation rates increase.

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.

The paper presents airtightness measurements results of the multi-family building. The tests were carried out in several ways, the results obtained by different methods were compared and the likely reasons for the discrepancy of results were indicated. The object of measurements was a six storey building with 47 dwellings equipped with natural ventilation. Air inlet to the rooms through the window trickle vents controlled by relative humidity of air. Air is extracted through vertical extract ducts made of ceramic blocks.

Hand-written results are a thing of the past. See how your phone or tablet and common testing gear can perform an automated cloud based test with secure data storage. Retrotec’s new rCloud app allows technicians use their iPhone or 4G tablet to perform a fully automated blower door or duct test.
The rCloud app is more than an automated testing, it provides an entire data set from exactly where, when and the conditions of the test. It “captures the moment”