Variabel Ventilation

Abstract: A lot of people today spend most of their lives indoors. Both at home and at work time is spent in areas where the climate is not governed by the weather but by ventilation systems meant to create a suitable indoor climate. Despite having such a central part in society the subject of ventilation seldom gets very much attention, and in the current situation it is not a foregone conclusion that indoor air quality and climate is satisfactory. Those who build the homes and premises normally explain this as a result of cost considerations, but essentially the situation originates from other issues. A more accurate explanation is that there are some problems concerning the planning stage of ventilation systems, which implies both a highly simplified designing approach and the price, not the function and quality, being decisive. The problems have been confirmed by several sources and research is in progress within the area in order to address the underlying issues. Among other things, various types of test-bed housing is constructed in several parts of the world, designed for measurement and data collection in a real living environment. Such projects can both verify different system´s function and promote the development of new innovations, but also help in creating well-justified research material regarding, among other things, different ventilation solutions such as for example variable ventilation. One of these projects, called KTH Live-in Lab, is located at KTH in Stockholm. This report presents a work regarding comparisons of different ventilation solutions for such a student apartment as constructed in the ongoing research project KTH Live-in Lab. The work focuses on both finding a suitable system and then link the results to an adequate combination for use with variable ventilation. In order to deal with today´s problems within the area, the work is focused on deviating from the current conventional approach and ventilation design. The result is illustrated digitally in the form of computer simulations of air flow in a virtual model of the apartment, and comparisons led both to a number of conclusions, and proposals of suitable and unconventional solutions. For non-variable ventilation systems, a suitable system consisted of one ventilation inlet placed at ceiling level and two outlets whereof one at ceiling level and one at floor level. For variable ventilation, the results showed that the system solution should suitably be combined with the ability to switch to an inlet at floor level at nights and other scenarios without activity and movement in the apartment. Other conclusions are mainly about findings regarding how certain design variations affect the characteristics of the ventilation system.