7.1. Active versus Passive

Passive solar heating uses quite different design strategies since it involves building elements rather than regular collectors. Passive solar has been around for millennia and is considered the low hanging fruit, so to speak; however, it requires careful design and is often difficult to implement in a retrofit scenario. Thus, a medium commercial building in an urban setting would have very limited options for renovation at reasonable cost toward a passive heating solution. At the same time, if you are designing a new building, the entire façade, orientation, and structure of the building can be leveraged to maximize solar utility passively through awnings, placement of thermal mass, rotation of the building, and more. Although most of the lessons in this course focus on active solar thermal energy conversion, we should not underestimate the impact of passive solar heating methods. While some passive heating methods can be cumbersome or may require some user input to keep costs down (e.g., movable shade elements), the thermal comfort of a space and the subsequent heating costs can be greatly impacted by careful design and the effective use of passive solar thermal energy conversion techniques. In this course the passive techniques are reviewed only briefly.