PR2011

Normally, the design of a ventilation system in a dwelling is based on national regulations, related design rules, building tradition and general knowledge about healthy indoor air quality, ventilation and air handling units. In practice, the actual performance of ventilation systems is determined by ventilation components, building properties, outdoor environment and occupant behavior. Unspecified items in the design rules and uncontrollable items in the design stage will bring uncertainties which may cause the actual performance deviating from the designed performance.

The paper presents the whole year simulation of humidity based demand controlled hybrid ventilation in multiapartment building. The simulation was performed for NAPE (National Energy Conservation Agency) multifamily residential reference building. This allowed the authors to compare obtained results with earlier investigated behaviour of the NAPE building with passive stack ventilation and mechanical exhaust ventilation.

As part of a project aiming at assessing ventilation in low energy buildings, this study analyses the performance of innovative ventilation systems used in a single-family building. Five ventilation systems are investigated by simulation using SIMBAD Building and HVAC Toolbox. The results then show better performance in terms of energy demand and indoor air quality (IAQ) for balanced ventilation systems, either permanent or intermittent management.

Wind is a potential dominant factor regarding the air infiltration through building envelopes. Due to its dynamic characteristics, quite complex aerodynamic phenomena arise around a structure or through cracks and openings. Energy perfomance is influenced by the climate conditions and thus it should be much more researched. Despite the fact that steady state measurements of infiltration rates offer a simple and easy way of estimating an enclosure’s airtightness level, a supplement to those methods might be imposed.

Most European standards and national regulations about ventilation rates are based on indoor air quality assumptions in terms of contamination. On the other hand, indoor air humidity is important for human health as well. In case of high flow rates during the heating seasons in cold climates, the indoor air humidity tends to low values.

A study of excessive air leakage in the ductwork of a large pharmaceutical plant located in the Southeast United States is executed in order to determine the energy loss associated with the excessive ductwork leakage. Much of the air supplied by the ductwork is delivered to clean rooms. The analysis requires the development of a model that is used to predict the increased energy costs. The model is applied for each 15 minute interval over the entire year (approximately 35,000 data points).

The feasibility of good air-tightness in new buildings can be determined based on the obtained air tightness classes as defined in EN 12237. In this paper a model is described which allows to calculate the energy loss caused by leak losses in ventilation systems based on the air tightness class and the feasibility of realising a good air-tightness.

This paper gives a quick overview of the PRAXIBAT programme led by the French Agency for Energy and Environment to improve building professionals skills to achieve low- or nearly zero-energy buildings. It looks more specifically at the initiatives targeted at ventilation systems installers, with practice-oriented trainings in quasi-real conditions.

Portugal introduced, for the first time, in the 2006 Building Regulations, a requirement on the airtightness of the ductwork in new HVAC installations. A test is required during commissioning. Data on compliance is however still quite scarce to conclude how effective this requirement is in practice.

This paper presents some results from the Work Package 5 in the HealthVent project supported by the European Commission. One of the objectives of the project has been to review and critically evaluate the existing requirements on ventilation and IAQ defined in national building codes and European standards. The project’s focus has been set on ventilation rates, pollutants, noise, temperature and draft in dwellings, offices, schools and kindergartens. This paper presents a summary of the values given in European regulations and results of comparisons.