The performance of ventilation systems in apartment buildings

In Finland 12 apartment buildings were investigated as a part of European project HOPE. There were one building with passive stack ventilation with fan assisted exhaust air ventilation, four buildings with mechanical exhaust ventilation only and seven buildings with mechanical supply and exhaust air ventilation system. Altogether 600 questionnaires were returned. Modern passive stack ventilation system with separate exhaust fans in kitchen and bathroom did not assure sufficient ventilation even in March when ventilation rates and CO2-levels were measured. Thermal comfort problems (too cold and draught) were common with passive stack ventilation and mechanical exhaust ventilation without any heating of outdoor air. The fresh air radiators gave the best satisfaction. Thermal comfort problems were common also during summertime due to overheating of apartments. The spread of environmental tobacco smoke was the most common indoor air related problem in apartments together with kitchen hoods performing not satisfactory.