The material presented in this paper highlights some aspects of""two research projects, The control of natural ventilation , and Night cooling strategies . The research has led to the development of generic control strategies. These have evolved from consideration of the control strategies used in naturally ventilated buildings utilising Building Management Systems (BMS) control together with experience obtained from monitoring three naturally ventilated buildings. The site monitoring has also led to recommendations being provided for commissioning and fine tuning procedures.
In line maintenance hangars, air planes stay about 2 hours, usually at night-time. The coolingdown of the inside air during the opening time of the hangar gates (up to 5 times per night, lasting 15 to 30 minutes each) has a considerable impact on the comfort conditions for the workers, and on the energy required for reheating. The time-dependent air flow rates and associated heat loss rates during the door opening and closing cycles is assessed by simple transient thermal models and CFD (Computational Fluid Dynamics) calculations.
Air flow measurements and simulations were made on a 13-story apartment building to characterize the ventilation rates for the individual apartments. Parametric runs were performed for specific conditions, e.g., height, orientation, outside temperature and wind speed. Our analysis of the air flow simulations suggest that the ventilation to the individual units varies considerably.
The ventilation of an attic is critical in estimating heating and cooling loads for buildings because the air temperature in the attic is highly sensitive to ventilation rate. In addition, attic ventilation is an important parameter for determining moisture accumulation in attic spaces that can lead to structural damage and reduced insulation effectiveness. Historically, attic venting has been a common method for controlling attic temperature and moisture, but there have been no calculation techniques available to determine attic ventilation rates.
A demand controlled ventilation system with humidity as the control parameter was tested in an experimental demonstration project in 16 apartments. In the same housing complex 16 identical apartments with a constant exhaust airflow rate were included in the test as a reference group. The purpose of the study was to investigate whether satisfactory physical health conditions could be reached in the humidity-controlled in apartments, while at the same time reducing the use of energy for heating.
A laboratory, designed to form the basis for research aiming at increasing the knowledge concerning the interactions between indoor pollution sources and the indoor environment, has been taken into operation. One long term purpose of the activities in the laboratory is to develop theoretical models, based on experimental data, for the prediction of the air quality in real buildings. At present, the experiments focus on the relationship between the emission of pollutants from building materials and the environmental parameters, i.e.
The ventilation standard was investigated in a large number of school buildings located in Gothenburg, Sweden as part of a current large-scale renovation programme. This article reports on experiences from the reconstruction work involved. Results from air quality measurements comprising TVOC (total volatile organic compounds) and CO2 measurements are presented. The results show that the indoor air quality is considerably influenced by outdoor contamination sources and that cleaning products and floor polish can, temporarily, add to the pollution content in classrooms.
A new multizone airflow and contaminant dispersal program CONTAM93 is described. While this program is based on existing theory of network airflow analysis and contaminant dispersal, it employs a unique graphic interface for data input and display. The interface uses a sketchpad to describe the connections between zones and icons to represent zones, openings, ventilation system components, and contaminant sources and sinks. The program, its graphic interface and plans for its further development are described.
Summary report and evaluation of the Roomvent 94 conference in air distribution in rooms. The roomvent conferences are dedicated to problems if aero- and thermo-dynamics of ventilated rooms.
This paper presents a research project, of which the primary goal was to investigate the possibilities of designing a natural ventilation system with heat recovery solely driven by the indoor-outdoor temperature difference. The theory used for design of a prototype system and the prototype itself is describes as well as the measured performance. The project has shown that it is possible to design a natural ventilation system solely driven by the difference between the temperature indoors and outdoors with a heat recovery efficiency of 40-45%.
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