Passive Solar

From Swikipedia

Introduction

Passive Solar is the use of glazed areas in houses to capture solar heat, much as with greenhouses. Unlike 'active' solar devices, which have pumps to circulate water through a 'solar collector', passive solar systems have no moving parts-hence the name.

Passive Solar technologies are means of using sunlight for useful energy without use of active mechanical systems (as contrasted to active solar). Such technologies convert sunlight into usable heat (water, air, thermal mass), cause air-movement for ventilating, or future use, with little use of other energy sources. The goal in passive solar building is the optimal balance of mass, glass, and insulation for a particular site and house design.

Brief Description

Passive solar energy:

Passive solar heating and cooling represents an important strategy for displacing traditional energy sources in buildings. Passive solar techniques make use of the steady supply of solar energy by means of building designs that carefully balance their energy requirements with the building's site and window orientation. The term "passive" indicates that no additional mechanical equipment is used, other than the normal building elements.

All passive techniques use building elements such as walls, windows, floors and roofs, in addition to exterior building elements and landscaping, to control heat generated by solar radiation. Solar heating designs collect and store thermal energy from direct sunlight. Passive cooling minimizes the effects of solar radiation through shading or generating air flows with convection ventilation.

Another solar concept is daylighting design, which optimizes the use of natural daylight and contributes greatly to energy efficiency. The benefits of using passive solar techniques include simplicity, price and the design elegance of fulfilling one's needs with materials at hand.

Basic ideas in passive solar buildings:

• Choose the Right Building Site

The more southern exposure, the better is the site for passive solar. A steep north-facing slope, or large trees or other buildings in the wrong places will cut back on your solar window.

• Let The House Face The Sun

It is very important to orient the long axis of the house east-west, so that as much wall and roof length faces directly south as possible. The most livable homes group the kitchen and dining room to the east, for morning light.

• South-Facing, High Quality Windows

Passive solar houses have large window areas on the south side where the sun comes from, and minimal windows on the north side.

• Super insulate, Build Tight, Ventilate Right

High R values and minimal air leakage are the most important factors in building any low-energy house.

• Thermal Mass

Thermal mass inside a building moderates temperature swings by storing heat when the sun is shining and releasing heat back into the building when it begins to cool off. Materials commonly used for mass include water, concrete, masonry, and earth.

• For The Best Passive Solar Design

Time spent on the building site observing sun, wind, rain, and ground water pays off in selecting the ideal location and design for the house. Earth-sheltering reduces heat loss and thermal swings. Build an airlock for exterior doors. Select materials carefully for durability and lack of toxicity. Integrate the heating and ventilation systems into the overall building design. Provide space for solar/mechanical equipment, and extra pipe and conduit runs for future solar system expansion.

References:

http://en.wikipedia.org/wiki/Passive_solar

http://www.newenergy.org/sesci/publications/pamphlets/passive.html

http://www.oikos.com/library/energy_outlet/passive_solar.html