Airtight duct systems [a simple way of improving a building’s energy efficiency without increased investment]

Against the background of increased global demands for energy efficiency, property owners should raise the standards of ductwork systems for ventilation, heating and air conditioning. This would not only save energy, but also mean lower installation costs, shorter assembly times and better air quality thanks to less leakage. The importance of energy-efficient buildings will increase in the future, not only due to rising electricity prices, but also due to increased environmental awareness.

Calibrating measurement gauges – expense and findings

This presentation will explain what exactly calibration should mean. It will also look into the hierarchy of and the differences between the calibration labs of national standards, accredited labs (like DAkkS, a national government-appointed accreditation body in Germany, or Cofrac – Comité français d’accréditation – in France), and manufacturer’s calibration labs. Even the labs themselves must have their own measuring devices checked in order to guarantee what is known as traceability to national standards, and to determine the measurement uncertainty of their testing devices.

Uncertainty in airflow rate estimation of daytime ventilation associated with atmospheric stability

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.

Numerical evaluation of the airtightness impact on airflow pattern in mechanically ventilated dwellings in France

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.

Infiltration and Ventilation in a Very Tight, High Performance Home

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.

Characterization of sealants and expanding foams

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 -what are the driving forces

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.

Laboratory investigation on the durability of taped joints in exterior air barrier applications

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.

Impact of air infiltration rates on moisture buffering effect of wooden surfaces

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.

Airtightness Data and Characteristics of 752 Residential Units of Reinforced Concrete Buildings in Korea

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.

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