leakage

It is foreseen that the 2012 version of the French regulation will include a minimum requirement for the envelope airtightness of residential buildings, with two options to justify its treatment: a) measurement at commissioning or b) adoption of an approved quality management approach. This paper describes the qualification process for authorizing technicians to conduct airtightness measurement when the result is to be used in the EP-calculation method. It also discusses the requirements set for approved quality management approaches.

We have sought to accurately quantify automobile HVAC air flow rates in four passenger vehicles,under a range of different ventilation settings and speeds. We used Sulphur Hexafluoride (SF6) as atracer gas, coupled with a portable doser/sampler system to quantify flow rates and leakage.Results of this work indicate a linear increase in HVAC air flow rate with increasing vehicle speed forall vehicles. Older vehicles were much less airtight than newer vehicles, a likely reflection on improveddesign and reduced door seal deterioration observed in the newer vehicles.

The Energy Performance of Buildings Directivementions that each member states' energyperformance (EP) calculation methodology mayinclude envelope airtightness. In fact, manymember states have included envelopeairtightness in their EP calculation method.Many countries have also specific requirementsfor ductwork airtightness. However, they seemto be unequally successful in achieving a markettransformation. This paper describes themechanisms that have been used in somecountries, with a special focus on success storieswhich could inspire other member states.

Single- and double-section manufactured homes were instrumented in 2001-2003 to measure continuous energy usage and air infiltration with respect to the environmental conditions of a windy cold dry climate. The test site near Arlington, Wyoming, USA is ideal for testing the energy (and structural) performance of manufactured housing due to the naturally occurring high winds (in excess of 35 m/s annually) and temperature extremes (+35 to -35C). Tests included tracer gas monitoring, pressurized leakage tests, and infrared (IR) video scans.

This paper asks questions about what is the right tightness and a warns against too tight tightness guidelines.The author gives advice :- A tight building envelope should reduce average natural infiltration (due to wind and temperature) to 0.05 to 0.1 air change per hour.- A tight building envelope should contain the desired air pressure field.- A building envelope should not be too tight because of the unbalanced airflows that can create excessive levels of depressurization.

The purpose of that study was to quantify the effect of the variables (previously identified during the first phase of that study conducted from 1999 to 2002) concerning smoking room performance under controlled laboratory conditions.In a test chamber simulating a smoking room, 27 experiments were conducted.

Describes a recently developed technology from California which provides a way to duct seal installed residential systems in two to three hours. The Aeroseal technology uses a fan to blow a small quantity of dry adhesive particles through the temporarily seald duct system. With registers and the furnace blocked, the suspended sticky particles travel in the airflow toward the only place left for the air to exit - the cracks and leaks. As the air stream turns sharply through leaks, the particles are deposited directly on the edges of holes to create seals.

Existing models for predicting air infiltration account for three dominant variables, namely envelope leakage characteristics, indoor-outdoor temperature difference and wind speed. Building shape, wind direction and sheltering, also influence the wind induced component of air infiltration. In this report, these variables are examined analytically and experimentally using wind tunnel data and field infiltration measurements. A sensitivity analysis of a power law infiltration relationship reveals that these factors are most significant at small temperature differences.

Describes measurements made to compare ventilation rates in six Belgian houses with both natural and mechanical ventilation systems using O2 and N2O as tracer gases. Ventilation rates were correlated with wind speed. Air leakage across individual components of the house was measured and from this the distribution of leakage areas calculated.