The Greenhouse is usually a building in which plants are grown. It is often used in architecture to benefit from the solar gains and reduce the heating consumption. The project highlighted the fact that in a mild-warm climate the greenhouse is not the correct solution to optimize the inside comfort.
The Client wanted to install a greenhouse on the front side of its house. In this climate the most suitable passive strategy is to benefit from the Natural Ventilation, while screening the direct solar radiation and a good level of thermal inertia.
greenhouse contribution 7,2% of improvement
The installation of a greenhouse on the south façade is not a good choice. The heating demand didn’t decrease sufficiently.
This happens because the specific climate of Barcelona is not the most appropriate for this heating strategy. Especially when this is only based on heating a volume of air.
Generally speaking the percentage of success of a passive heating strategy in this climate is about 30%.
The greenhouse effect is only appraisable during sunlight hours. At this time the heating demand is low and the Building envelope (jn this case) doesn’t have enough capcity for keeping the heat gains.
A more realistic scenario including also lighting and equipment heat gains would play even more in favor of excluding solar heating strategies.
Summer climate strategy
Study for the pergola + natural ventilation
Natural ventilation combined with a solar shading system play an important role in reducing the demand of cooling in summer, late spring and early fall. The Pergola, if properly designed, is able to obstruct direct solar radiation and facilitate diffuse daylighting.