Active House vs. Passive House
The so-called "Active" is the need for energy to play a role. Power or other fuels are usually used, such as a boiler used for heating or an air conditioner used for cooling. Environmentally friendly methods such as installing solar panels to actively capture the sun and convert it into power system. Other active methods include solar geothermal thermal energy, energy saving gadgets, and complex automatic control, so as to introduce fresh air when needed, and to control shadows by automatic louvers and external awning.
"Passive" uses natural elements, especially solar and wind, to achieve comfort. This method is based on the traditional methods used in residential design for centuries. The first basic principle of passive design is the direction of the building. It should take advantage of the way of the sun in a way. For example, the southern glass in the northern hemisphere is ideal, because it can capture indirect light (summer) or direct light in winter. In hot summer, it is necessary to prevent direct sunlight, keep the house cool, and allow natural lighting. Passive cooling strategies include planting deciduous trees in summer to cover houses, or Transcendence over windows. They should be positioned to stop the summer sun, while allowing low - angle winter light to penetrate and heat the building. Other key elements of passive design are insulation walls, floors and roofs, air tightness, solar gain, natural light and natural ventilation.
However, in modern architecture, it is difficult to solve the need of comfort in indoor environment with the traditional "passive" method, so the "hybrid" building energy saving technology with active and passive combination is formed.
Although the active architecture looks the opposite of the passive architecture, the two concepts are not in conflict. The active architectural design can use some passive ways to minimize energy use and achieve a higher level. Through photovoltaic panels and solar water heaters or ground source heat pumps, the building itself needs to supply energy. It is not only a zero energy building, but also the active building can generate electricity and generate economic benefits. Most of the world's active buildings are powered by solar cells to provide energy for facilities, and floor heating is also provided by solar panels. The system is controlled by a computer, monitors the temperature, controls the switch, and regulates the window. Due to the consideration of comfort, passive buildings also increase the active mechanical fresh air, a small number of heating and air conditioning facilities, and try to improve the combination with renewable energy, such as solar energy and wind energy.
There is no essential difference between "active" and "passive" in the pursuit of building energy efficiency, but there is a slight difference between the technological line and method pursued at the initial stage. The active architecture seeks to balance the indoor comfort and attraction while pursuing the optimization of energy saving. The passive building seeks the best balance between the most effective use of natural and renewable resources and the structural design and cost of the building.
FutureVision has an experience that is rare in China of construction of both Active and Passive buildings including practice of relevant international standard, and an experience of design, counselling and the construction.