Walipini

A walipini (also known as an underground greenhouse or pit greenhouse) is a passive solar greenhouse built partially or entirely below ground level. The word "walipini" originates from an Aymaran word meaning "warm place."

Walipinis utilize the earth's natural insulation to maintain relatively stable temperatures year-round. The surrounding soil mass acts as a thermal battery, absorbing and storing heat during warmer periods and releasing it during colder periods. This buffering effect reduces temperature fluctuations inside the greenhouse, extending the growing season and providing a more consistent environment for plants.

Key features of a walipini often include:

• Excavation: The primary characteristic is its sunken construction, typically several feet below ground.
• Orientation: The structure is typically oriented to maximize solar gain, often facing south in the Northern Hemisphere.
• Glazing: A transparent covering, usually made of plastic or glass, allows sunlight to enter the greenhouse. This glazing is typically angled to optimize light capture during winter months.
• Insulation: Insulation may be added to further reduce heat loss, especially in colder climates.
• Ventilation: Adequate ventilation is essential to prevent overheating and maintain air quality.
• Water Management: Proper drainage is necessary to prevent water from pooling in the walipini.

Walipinis are particularly beneficial in regions with harsh climates, such as high altitudes or areas with extreme temperature variations. They can provide a cost-effective and sustainable way to grow food year-round, reducing reliance on external energy sources for heating.