Available time for building construction is getting shorter, therefore the number of buildings which are built with lightweight building elements (LBE) is increasing. LBEs are elements of greater dimensions with low specific weight and low thermal transmittance. Their characteristic is also low thermal stability. By upgrading LBE with dual ventilated cavities (DVC) with counter flow becomes standard LBE a thermally activated building construction with increased thermal resistance and thermal stability. It enables using of solar radiation and heat recuperation from used air.

The EPBD prescribes an energy performance certificate for buildings. According to the nationalimplementations of the EPBD for non-domestic buildings the specific data of the building will begathered during the certification process and combined into a multi zone model describing buildingand building systems from an energetic point of view.

The potential for passive cooling of roof slabs incorporating an air cavity is important with respect tothermal comfort. Roof systems in traditional buildings, incorporated a ventilated roof or an air cavity.The concept has been proposed again in contemporary buildings in the construction of roof slabs,using a modular formwork system, where the cast in situ concrete slab is isolated from the screed with the introduction of a ventilated air space. The cavity is primarily intended to curtail the conduction and inward radiation of heat from the intense solar insolation on the concrete roof.

Important oversizing factors are observed for room air-conditioners leading to important energy wastes and costly summer peak demands for utilities. This article intends to show that sizing decisions should be based on dynamic simulation results and include an assessment of the air conditioner part-load performance. The sizing methodology established is applied to evaluate different oversizing levels for different types of buildings, climates and systems. This enables to compare our methodology to typical rules of the thumbs applied in France.

A promising approach to reduce the primary energy demand of office-buildings without violatingthermal comfort is passive cooling by thermo-active building systems (TABS). The presented studyintroduces two low-energy office buildings within the framework of the German programme ENOBwhich are conditioned by TABS mainly supplied by geothermal energy.

A method for controlling the temperature of the occupancy zone in a room equipped with a fan coil ispresented. The heterogeneity of the air velocity field and the temperature distribution is considered. As it leads to a system with a great number of differential equations, the Proper OrthogonalDecomposition is applied to build a low order model. Moreover, the value given by a sensor oftemperature enables the estimation of the temperature in the occupancy zone with a state estimator.The performances of the model are shown through the first results of simulation.

Responsive Building Elements (RBE), as defined in International Energy Agency - Annex 44,are building construction components which are actively used for transfer and storage ofheat, light, water and air. These construction elements (like floors, walls, roofs, foundationetc.) are logically and rationally combined and integrated with building service functions suchas heating, cooling, ventilation and lighting.

Although unanimously acknowledged by the experts for its performances as regards energyeffectiveness and indoor air quality optimisation, humidity sensitive ventilation still too often suffersfrom a lack of knowledge inherent in its singularities. The matter of this article is thus to bring a newlighting on the humidity sensitive ventilation determining airflow rates in the calculations of ductworksdimensioning and in the energy impact related to the air renewal.

Detailed mathematical models of VAV equipment and subsystems have been developed and used tocompose larger DCV systems with a large degree of detail. The models and systems take intoaccount both flow/pressure distribution and thermal/contaminant dynamics. The models have beenvalidated against measurements. A number of detailed simulation cases have been conducted. Theresults show that energy usage depends strongly depends on occupancy, flow rates, chosen setpoints as well as the outdoor temperature.

Demand-controlled ventilation (DCV) has largely been documented in the literature through fielddemonstration projects and computer simulation studies. However, in France and in the majority ofEuropean countries, the use of this technique is still quite limited.