PR2006

The energy consumption of a building is evaluated by neglecting the heat loss which can occur when the air passes through the envelope. However, recent studies showed that air leakage plays asignificant role by affecting the thermal performances of walls and the energy consumption. Moststudies have focused on the quantification of air leakage flows through the building shell, withoutaddressing the problem of the heat exchange between this airflow and the construction materials asthe air passes through the envelope.

European Directive for Energy Performance of Buildings (EPBD) was approved in the beginning of2003. The transition period is 3-6 years depending of the article. European StandardisationOrganisation (CEN) has drafted several standards to help the member countries implementing thedirective. One of these is the Criteria for the indoor environment including thermal, indoor airquality (ventilation) light and noise. The standard specifies design values of indoor environment,values to be used in energy calculations, and methods how to verify the specified indoorenvironment in the buildings.

Since the energy-crisis of the 70’ies, the trend goes to energy-saving constructions, that have strongly changed our way of building. The development of highly insulated houses in combination with manual window-airing leads to problems concerning a good q

The design of ventilation equipment is important because it affects the ventilation performancedirectly. To improve the ventilation efficiency of the displacement ventilation, a new ventilation system was proposed in this study. The experiment was performed to measure the fume concentration and the visibility at four points under working conditions. In experimental results, the concentration of dust with a new ventilation system was decreased by about 42-60% compared to that of the existing system. The visibility was increased by about 11-18%.

Positive input ventilation (PIV) systems were installed in a new build housing development inBallantrae in south west Scotland; utilising a glazed sunspace on the south elevation of each dwelling to augment the energy saving potential of the installation. Data logging equipment was installed in each dwelling to enable assessment of the energy efficincy improvement to the property over traditional systems of ventilation.

Regular maintenance, such as the cleaning of filters, is important for the efficient operation ofresidential ventilation systems. The main objective of this study is to investigate effect of regularmaintenance on fan energy use and ventilation performance by using a test dwelling employingbalanced ventilation system. Experimental tests were directed with simulating the decrease of the airflow rates on terminals. Without cleaning, SFP based on the net air flow rate can indicate by 2.7 times compared with cleaned system.

In this study the COwZ model (COMIS with sub-zones) was modified to allow dynamic simulations ofindoor thermal conditions, humidity and pollutant transport and concentrations throughout wholebuildings. The new version of COwZ may be used to predict the impact of heat supply and ventilation options on indoor conditions, particularly temperature and humidity, over extended periods, with dynamic weather conditions and varying occupant activities.

The actions to limit the energy consumption and the electricity demand lead in Europe and inFrance to think about the energy labelling of the consumption of the fans used in ventilationsystems. This is a complicated task as it has to take into account the multiple possibleoperating conditions, the eventual presence of a regulation system and the type of use.A study supported by Ademe has been carried out in order to propose a method for labelling ofthe ventilation units. This study was divided in four phases.

The paper discusses a methodology for thermal analysis applied to buildings in which the stochasticnature of the external forces is concerned. The considered forces are ambient temperature and solarradiation. The stochastic approach presented in this paper, consists in modelling the climatic inputs as a Markov process which have been injected on a reduced modal model describing the thermalbehaviour of the building.

For the conservation of an important museum collection in a historic building a better controlled indoor climate may be necessary. One of the most important factors is controlling relative humidity. Museum collections often are part of the interior of a historic building. In most cases the installation of an expensive air-conditioning system may cause damage to the building and its historic authenticity. Furthermore humidifying may lead to dramatic indoor air conditions with mould and condensation effects on the cold indoor surfaces or even internal condensation in the construction.