Simulation-based assessment of natural and mechanical ventilation solutions for renovated apartment buildings in Denmark

Many European buildings require renovation, often involving window replacements and improved airtightness, leading to increased mold risk and indoor air quality (IAQ) issues. Solutions include adjustable air inlets with mechanical exhaust or balanced heat recovery ventilation. Using building performance simulations, we studied control strategies for renovated apartment building with natural or mechanical ventilation. CO2 - controlled air inlets proved most effective for IAQ and energy reduction. In different apartment positions, air inlet performance varied based on available stack effect. Mechanical exhaust cases were less affected by airtightness changes. Altogether, the mechanical ventilation was more robust, but all strategies were sensitive to closed doors.