Controlled Natural Ventilation for Energy Efficient Buildings

• Study that assessed thermal comfort and summer cooling potential using natural ventilation.
• Reviewed multiple studies and compiled various study findings on efficacy of natural ventilation and reduction to energy demand in various climates.

Natural ventilation of buildings has the potential to significantly save cooling and fan electrical energy. However, it is still not widely applied, because only limited information is available on the thermal comfort and indoor air quality of office buildings without air conditioning. Steady state ventilation air flow rates were therefore systematically simulated using both analytical and airflow network methods for different boundary conditions such as temperature and pressure differences across openings for different opening types. Coupled airflow network and dynamic building simulations were carried out to determine the annual thermal comfort and energy savings. The results for the three moderate climate locations Germany, Italy and Turkey show that while indoor air quality can be easily maintained for all opening typologies, the summer cooling potential and thermal comfort strongly depends on the natural ventilation strategy. Control over the openings is crucial for all cases, as otherwise the office rooms tend to cool down too much even in summer conditions.

Highlights
► Discussion on the feasibility of natural ventilation. ► Identification and application of performance indicators for natural ventilation. ► Determination of ventilation potentials for fixed and dynamic boundary conditions. ► Parametric determination of associated energy savings for moderate European climates. ► Comparison with an identical office room with mechanical ventilation.