The principles of bioclimatic architecture, when applied with an understanding of the surrounding climate and geography, can simultaneously increase a building's efficiency and create a more comfortable living space. Passive measures like solar panels, rainwater and grey water harvesting, openings for natural light, and cross-ventilation are all low-cost, high yield methods of increasing a home's thermal comfort and efficiency and decreasing its carbon footprint.
Nothing is more rational than using the wind, a natural, free, renewable and healthy resource, to improve the thermal comfort of our projects. The awareness of the finiteness of the resources and the demand for the reduction in the energy consumption has removed air-conditioning systems as the protagonist of any project. Architects and engineers are turning to this more passive system to improve thermal comfort. It is evident that there are extreme climates in which there is no escape, or else the use of artificial systems, but in a large part of the terrestrial surface it is possible to provide a pleasant flow of air through the environments by means of passive systems, especially if the actions are considered during the project stage.
This is a highly complex theme, but we have approached some of the concepts exemplifying them with built projects. A series of ventilation systems can help in the projects: natural cross ventilation, natural induced ventilation, chimney effect and evaporative cooling, which combined with the correct use of constructive elements allows improvement in thermal comfort and decrease in energy consumption.
The IAAC (Institute for Advanced Architecture of Catalonia) has developed a series of advanced materials and systems for air conditioning and passive ventilation, allowing homes to reduce interior temperatures up to 5 degrees lower while saving the electricity consumption caused by the traditional air-conditioning. The systems are made from long-lifespan materials, which lower the costs of maintenance in the long-term and can be used as low-cost alternative building technologies.
The Passive House or Passivhaus is a standard of construction that emerged in Germany in the early 90's. Its secret is to combine high interior comfort with a very low energy consumption, almost nil, and at a very affordable price that allows to amortize the Investment difference with respect to a normal building in a very short period of time.
Passive buildings use bioclimatic architecture combined with high energy efficiency. Minimizing the use of conventional heating and cooling systems, buildings are designed to maximize light and solar radiation, with high isolation and a renewal of air through a ventilation system with a heat recuperator.
This is an energy concept applicable to any type of architectural design and any building system. Know some of its benefits:
1. Bioclimatic design
A fundamental aspect for an efficient building is a good study of the climate, orientation, form factor, volume, the capture of solar radiation in winter and its protection in summer, the shadows that the building will have and how Affect you.
2. High thermal insulation
A poorly insulated building consumes up to 30% more energy. Good insulation reduces heat losses in winter and summer profits and, therefore, energy demand for air conditioning.
3. Removal of thermal bridges
A continuous insulation layer, without interruptions and without weakening, avoids the thermal bridges, so common in conventional buildings and which cause a large part of heat losses in buildings.
4. High performance windows
Windows are the weakest element in a building envelope. Between 25% and 30% of the heating expense is due to heat losses from the windows. A good quality of the same and a correct installation is fundamental for a high energy efficiency.
5. Heat recovery
Mechanical ventilation allows the indoor air to be continuously being renewed. Thanks to a heat recuperator, the air that, for example, can enter a winter day at 0 ° when crossing (not mixing) with the one that leaves at about 22 °, yields the internal energy transforming the 0 ° into about 18 °, depending on Of the efficiency of the recuperator and without any heating system.
In the passive houses, the airtightness is taken care of by sealing all the joints between the different materials of the building. In this way, there are no unwanted air infiltrations in the building.
For the homogeneity of the interior temperatures, for the high acoustic insulation and for the quality of the air (in continuous renovation and filtration, therefore free of CO2, VOCs, dust, dirt, pollen, ...).
Filtered air prevents the presence of dust and pollen, which reduces allergic reactions. The low concentration of CO2 and VOCs reduces the feeling of tiredness, some ailments such as headaches, irritation in eyes, nose, throat, dryness of the respiratory system and some diseases.
9. Efficiency, sustainability and profitability
Efficient due to low energy consumption and, consequently, economic. Sustainable because the CO2 that ceases to emit a passive house of 350m2 in a year is equivalent to CO2 that absorb about 1,000 trees in a year. A building built under the Passivhaus standard has a construction surcharge between 5 and 10% higher, but this is profitable between 5 and 10 years due to energy saving and maintenance.
Technical tests and certification are the last step to be able to say that a building is built under the Passivhaus standards. It is the only guarantee that the building complies with the requirements established by the Passivhaus Institut of Germany and the level of interior comfort and the energy quality of the construction towards the client.
The project's two residential towers -- measuring 80 meters (262 feet) and 112 meters (367 feet) respectively -- play host to around 20,000 trees, shrubs and plants. They spill out from irregularly placed balconies and crawl up the structures' sides. By Boeri's estimates, there are two trees, eight shrubs, and 40 plants for each human inhabitant.
The purported benefits of this garden architecture transcend aesthetics. Greenery, supposedly, provides shade to apartments, psychological benefits to residents and a home to wildlife. (There are, Boeri said, "hundreds of birds, more than 15 different species" nesting on the towers' various floors.)
But the architect's proudest claim is that the buildings absorb 30 tons of carbon dioxide and produce 19 tons of oxygen a year, according to his research, with a volume of trees equivalent to more than 215,000 square feet of forestland.
"The ability to enlarge green surfaces inside and around our city is one of the most efficient ways to try to reverse climate change," he said. "So, a vertical forest is one of the possible ways to ... enlarge biological surfaces, in the horizontal and the vertical. (The solution is) not only gardens. Why not also the side of the building?"