To gain access to information on energy use in office buildings, the German Federal Ministry forEconomy launched an intensive research and demonstration programme in 1995. In advance of theEU energy performance directive a limited primary energy coefficient of about 100 kWh m-2a-1 as agoal for the complete building services technology was postulated (HVAC + lighting) for alldemonstration buildings. A further condition was that active cooling be avoided.
The aim of this work is to study the influence of global heat transfer coefficient (Utot en W/m2.K) of the opaque walls (walls and roofs) and of the glazed walls (bays) on the annual consumption of heating, cooling and overall consumption energy. We analyze the number of hours of heating and cooling under operation with partial load and full load. Profiles of indoor temperatures are also given. The work is established on several office buildings defined according to a typology built within the framework of a study on energy savings in air-conditioned office buildings in France.
About 100 office buildings in the Flanders and Brussels regions have been subject to a surveyof energy aspects and indoor climate parameters. Building characteristics and energy use havebeen mapped for all buildings; for 48 of them a database has been built containing buildingand room dimensions, materials used for the building shell, windows, glazing, solar shading,occupancy, equipment characteristics (heating, ventilation, cooling, lighting, office equipment.
Insufficient concern about energy efficiency during the design and/or the operation of a building is the main reason for the high energy consumption of existing buildings. The knowledge of facility managers about the real energy consumption is often poor, regular documentation or analysis of consumption data are not existing. Enerkenn therefore intents to develop a procedure to record and evaluate relevant energy data and to find out energy saving potentials with environmentally conscious and economically reasonable accuracy.
Since the beginning of this decade, natural ventilation in office buildings is receiving specific interest. There are two sorts of application. Natural ventilation can be a strategy for indoor air quality control. Besides it can be used as night ventilation during warm or hot periods. In this case the objective is to cool down the thermal mass and improve the thermal summer comfort. The EC JOULE NatVent project wanted to identify the barriers to the application of natural ventilation in office-type buildings in moderate and cold climates and to provide solutions.
NatVent™ is a seven nation pan-European project which aims to reduce primary energy consumption (and consequently C02 emissions) in buildings by providing solutions to barriers which prevent the uptake of natural ventilation and low-energy cooling in countries with moderate and cold climates. It also aims to encourage and accelerate the use of natural ventilation and 'smart' controls as the main design option in new-designs and major refurbishments of office-type buildings.