Comparative analysis of the energy impact of air infiltration for different ventilation systems

This work presents simulations results exploring the influence of the building air-tightness on the energy consumption of buildings for different hypothesis on the type of ventilation system. It shows that the energy impact is different depending on the ventilation system, and that buildings ventilated with a supply-extract ventilation system, even those without heat exchanger, are much more sensitive to air infiltrations than buildings ventilated with an extract ventilation system.

Analysis of ventilation systems in high performance homes in cold climates

The performance of three different ventilation systems in cold climate homes is discussed. Comparisons are presented of monitored datasets by contrasting operations of the three ventilation systems, the energy impacts on the overall HVAC systems, and resulting indoor environmental conditions. Whole building simulation results, based on ventilation system models using EnergyGauge and validated in part by the monitored datasets, provide normalized comparisons of HVAC system energy use.

Prediction of buoyancy-induced pressure difference across exterior walls of high rise residential buildings

It is very important to estimate the stack pressure difference across exterior walls for understanding the energy impacts of infiltration and ventilation in high-rise buildings, because stack pressure is likely to significantly affect energy load and is sustained over a long period. This paper presents a simple prediction strategy for estimating the pressure distribution in high-rise residential buildings, using key parameters that affect the magnitude and distribution of stack pressure.

Performance prediction of dwelling ventilation with self-regulating air inlets

This paper presents simulation results of the performance of ventilation systems with self-regulating inlets in different types of typical Flemish dwellings. Normal free air inlet vents have one major disadvantage: the complete dependence on the variable outside weather conditions (wind and temperature). The use of selfregulating inlets should minimize this impact, optimize the indoor comfort (no draught) and reduce the waste of energy by ventilation.

Development of design guidelines for tertiary sector buildings equipped with natural ventilation systems

This study considers the link between tertiary buildings design and equipments known as natural and hybrid ventilation or cooling. It focuses on the case of cross ventilated buildings and the envelope choices able to ensure comfort along with energy savings. This link is studied by simulating with TRNSYS various cross ventilation systems: by night, day or both. These are applied to typical situations as individual office, open-plan office, or meeting rooms. Studied rooms are chosen south oriented and subjected to medium internal gains.

Ventilation system qualtiy for dwellings : a pragmatic approach

As a result of the EPB directive, the Flemish government has established a new regulation due as from January 1ste, 2006. This regulation also imposes the presence of minimal ventilation equipment in new buildings. Various Belgian as well as international investigations report a lack of quality of installed ventilation systems, in individual dwellings as well as in utility buildings. Possible problems range from missing inlets, leaking air ducts to inadequate flow rates and acoustical complaints.

Performance evaluation of the hybrid ventilation system controlled by a pressure difference sensor

A hybrid ventilation system controlled by a pressure difference sensor was installed on a detached test house. Performance of this ventilation system was evaluated through the field measurement taken into account the different conditions of the air supply and the exhaust systems. The results of the measurement revealed that the exhaust airflow rate was relatively stable while the indoor-outdoor temperature difference varied and the wind velocity changed. The exhaust airflow rate met the target airflow rate of 64% during the whole measuring period.

On the impact of urban environment on the performance of natural and hybrid ventilation systems

The impact of the urban environment on natural and hybrid ventilation was investigated through experimental and computational procedures in the framework of RESHYVENT European Project. An experimental campaign was organized in two urban street canyons in Athens, during summer 2002, consisting of field and indoor experiments. The experiments aimed at the investigation of the impact of the various urban features on the efficiency of different ventilation systems.

Experiment of the mixing property and the heat exhaust effect under cross ventilation in a full-scale building model.

Cross ventilation is one of the most important techniques for achieving energy conservation and for maintaining a comfortable indoor environment in summer. But it is difficult to evaluate the effect of cross ventilation quantitatively and to design based on a quantitative evaluation, because the indoor environment is uneven and changes with the outside conditions under cross ventilation. The full-scale model experiment has been done under cross ventilation, and the properties of airflow in and around the full-scale model have been examined.

Review on ventilation rate measuring and modelling techniques in naturally ventilated buildings

Direct and indirect measuring techniques are available for determination of ventilation rate in naturally ventilated buildings. Direct measuring methods include measuring fan, propeller gauge, hot wire anemometer, particle image velocimetry, laser Doppler anemometer, and transit time sonic anemometer. Basic disadvantage of direct measuring techniques is that they are generally used for point or local measurements of air velocity.

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