Untersuchung des thermischen Komforts und der Luftqualität an vier neuen energieeffizienten Luxemburger Schulen mit und ohne Lüftungsanlagen

in Bauphysik (2017), 39. Jahrgang

A study was conducted in four new energy efficient schools in Luxembourg with excellent primary energy consumption values, where the indoor thermal comfort and the air quality was assessed by technical ... [more ▼]

A study was conducted in four new energy efficient schools in Luxembourg with excellent primary energy consumption values, where the indoor thermal comfort and the air quality was assessed by technical measurements and by surveys. Two schools were equipped with mechanical ventilation with heat recovery and two were without, i.e. ventilation there was manually controlled by opening the windows. Further to the C02-concentration as indicator for the air quality all other important comfort parameters were measured, why the well-known indicators according to FANGER could be calculated, i.e. the „Predicted Mean Vote (PMV)“ and the „Predicted Percentage of Dissatisfied (PPD)“. The individual perceived indoor comfort was analyzed by standardized questionnaires for a period of four weeks. One aim of the study was to compare natural ventilation by opening and closing the windows with the mechanical ventilation in all named aspects. In total there was a good agreement between the measurements and the survey. The results show that in general mechanical ventilation in schools lead to better physical measured values and to better subjective perception of the users. However those buildings suffer from a very low relative humidity, though it is rarely sensed by the occupants. Furthermore, in one of the mechanically ventilated buildings the air velocity was very high and led to draft-perception. The detected air temperature was heterogeneous and independent of the ventilation concept, leading to an individual judgement of PMV for the different buildings. Users should always have the possibility of interaction and control to adjust the indoor climate according to their individual needs and to correct smaller technical shortcomings. [less ▲]

Measured and perceived indoor comfort versus energy efficiency and users‟ control in Luxembourg‟s new school buildings

Scientific Conference (2013, September)

Room climate can be evident for job productivity and individual ́s health. Its realisation is often of high relevance for the building ́s energy consumption e.g. air conditioning vs. natural ventilation ... [more ▼]

Room climate can be evident for job productivity and individual ́s health. Its realisation is often of high relevance for the building ́s energy consumption e.g. air conditioning vs. natural ventilation. New school buildings in Luxembourg differ significantly regarding to energy consumption, heating, air-conditioning technology and technical control as well as interaction means given to the user. Several studies have shown that personal control plays an important role for the satisfaction with the room climate. Central research question was, how the technological control has to be designed that energy is used efficiently and users are still satisfied with the room climate. In this study technical features to control the room climate e.g. features for ventilation, opening windows and heating systems were summarized to an overall control factor to be compared with perceived control by the users. Physical room climate and its users ́ satisfaction level were measuredas well as the buildings ́ individual energy consumption levels were taken into account. 342 Teachers were asked by a standardised questionnaire during winter 2010/2011 in 31 new school buildings in Luxembourg, in 17 schools technical devices for air temperature, quality and humidity were installed. The results show a strong correlation between perceived control and room climate satisfaction as well as a significant correlation between the technical control factor and perceived control. Further results will be examined. [less ▲]