Influence of natural and mechanical ventilation on the indoor climate
Fedorak, Alexandra (2012)
Mikkelin ammattikorkeakoulu
2012
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201202282626
https://urn.fi/URN:NBN:fi:amk-201202282626
Tiivistelmä
In modern societies every building should have an adequate ventilation system to avoid a several number of problems: deficiency of fresh air, bad quality of indoor air (uncomfortable temperature, humidity, etc.), different contaminants in the air (from indoor or outdoor sources).
Choosing ventilation system is a question of health, comfort and cost. In this work, the most suitable variant of ventilation system is selected by analyzing measurements, comparing them with Russian and Finnish standards and with results of questionnaires. Investigations were carried out in three case buildings. The first has natural ventilation and is situated in Saint-Petersburg, the second has combined type of ventilation and is situated in Mikkeli, and the last one is also in Mikkeli and has mechanical supply and exhaust ventilation. Each case building was examined according to a six stage measurement plan. First is describing buildings, their ventilation systems and occupants. Second part is executing measurements (thermal conditions, flow rates, carbon dioxide (CO2) level). Third - accomplishing questionnaire about occupants’ sensations (where possible). Forth - analyzing results, bringing them to the simple visual form (diagrams, graphics, etc.). After those measurements results are compared with standards and questionnaire and finally, the following conclusions are made:
• Natural ventilation systems do not provide proper temperature (in summer) and CO2 level
• Mechanical exhaust ventilation systems provides good thermal conditions but are not energy efficient
• Mechanical exhaust and supply ventilation systems provide the most comfortable conditions. In spite of this, when designing these systems, the minimum humidity level should be calculated.
Choosing ventilation system is a question of health, comfort and cost. In this work, the most suitable variant of ventilation system is selected by analyzing measurements, comparing them with Russian and Finnish standards and with results of questionnaires. Investigations were carried out in three case buildings. The first has natural ventilation and is situated in Saint-Petersburg, the second has combined type of ventilation and is situated in Mikkeli, and the last one is also in Mikkeli and has mechanical supply and exhaust ventilation. Each case building was examined according to a six stage measurement plan. First is describing buildings, their ventilation systems and occupants. Second part is executing measurements (thermal conditions, flow rates, carbon dioxide (CO2) level). Third - accomplishing questionnaire about occupants’ sensations (where possible). Forth - analyzing results, bringing them to the simple visual form (diagrams, graphics, etc.). After those measurements results are compared with standards and questionnaire and finally, the following conclusions are made:
• Natural ventilation systems do not provide proper temperature (in summer) and CO2 level
• Mechanical exhaust ventilation systems provides good thermal conditions but are not energy efficient
• Mechanical exhaust and supply ventilation systems provide the most comfortable conditions. In spite of this, when designing these systems, the minimum humidity level should be calculated.