Читать книгу The Self-Sufficiency Handbook - Alan Bridgewater - Страница 20

A passive house is a house that uses no designated energy systems for central heating but instead has passive systems that gather waste heat from the domestic hot-water system, from cooking and lighting, and from the bodies of the people living in the house, along with heat from the sun. In this approach, the building itself or elements of or within the building are designed so that they take advantage of natural solar heating.

Operable windows, vents, Trombe walls, thermal chimneys, and insulation are the primary elements found in passive design. Operable windows are simply windows that can be opened, while Trombe walls use materials such as masonry and water that can store heat energy. The sun shines through the glazing and heats the masonry walls or tanks of water so that the space between the glazing and the wall becomes a thermal chimney. Vents set at floor and ceiling level in both the glazing and the interior Trombe walls are managed so that the currents of hot air that rise by convection between the wall and the glazing—in the thermal chimney—are directed either in or out of the building. Depending on the time of year, and the choice of open or closed vents, the rising hot air can be used either to heat or to cool the space.

Key aspects of passive design include appropriate solar orientation, the use of thermal mass, very high levels of insulation, and air locks or thermal buffers on exterior doors. The thermal mass absorbs heat during the day and emits it at night. Ideally, a passive house is a long, thin structure with total glazing on one of the long sides, situated so that the glazed side is facing the sun at midday. Passive systems are simple, have few moving parts, and require minimal maintenance.