Passive Solar Design Techniques
Posted by Big Gav in passive solar, passivhaus
Will Stewart has a guest post up at The Oil Drum on passive solar design techniques - Passive Solar Design Overview – Part 1. Also, at TOD, a post on the Passivhaus standard from another long-time commenter, marjorian - US Housing and the Passive Home Standard.
Passive solar refers to the design and placement of a building to enable solar heating without the need for sensors, actuators, and pumps, in contrast to active solar, which utilizes pumps/blowers, sensors, and logic control units to manage collection, storage, and distribution of heat. The two techniques are not exclusive, however, and can work together effectively.
As solar radiation (insolation) is a diffuse energy source, and not at the beck and call of a thermostat, passive solar design techniques are at their best when combined with other related methods, such as energy efficiency (insulation, weatherization, building envelope minimization), daylighting, passive cooling, microclimate landscaping, and a conservation lifestyle (i.e., temperature settings, raising and lowering of insulated shades, etc). Most of these topics will be covered in other articles, though passive cooling will be addressed in this series, which is intended as an overview, as a complete engineering treatment on passive solar design would require several dozens of articles.
Even though solar insolation is diffuse, and generally weaker the further away from the equator, it can be the basis for the majority of a building's heat energy input even in high latitude places such as Canada, Norway, Germany, the Northern US (Maine, New Hampshire, Michigan, Wisconsin, Minnesota, North Dakota, Montana, Idaho, Washington state, etc), Scotland, the Netherlands, etc. Even the US Department of Defense has a passive solar design guide. Design approaches such as Passivhaus have achieved up to 90% reduction in energy use over traditional building methods. In areas with reasonably consistent winter insolation, well insulated passive solar buildings with sufficient thermal mass storage can approach 100% of their space heating needs with passive solar. Enhancements can be added to existing buildings, through major or minor renovations, or through simple additions.