Passive Solar Heating Systems

The use of solar energy for heating buildings plays a significant role in reducing energy consumption. Passive solar heating systems are integrated into the structure of the building and operate based on the natural laws of heat transfer: they collect solar radiation, convert it into heat, store it, and distribute it within the interior space.

Their operation is based on the greenhouse effect: solar radiation passes through transparent materials (such as glass), is trapped inside, and converted into heat, which remains within the building.

The most common type of passive solar system is direct solar gain, where heat enters directly through properly sized and oriented openings (windows/skylights), ensuring the necessary solar exposure, especially during the winter months.

Other types include:

• Indirect gain systems, such as solar walls (glass bricks), greenhouses, and atriums.
• Isolated gain systems, such as solar collectors, which are installed outside the main building envelope.

The efficiency of these systems is maximized when integrated into south-facing façades (with an acceptable deviation of ±30°), which remain unshaded during the winter season.

Effective operation requires:

• Adequate thermal protection (insulation of walls and frames).
• Proper thermal mass (construction materials such as brick or stone), which stores heat and gradually releases it, balancing temperature fluctuations throughout the day.

During the summer months, solar protection measures are essential (e.g. deciduous trees, shading devices, awnings, or louvers), along with provisions for natural ventilation to maintain comfortable indoor conditions.