PASSIVE SOLAR ASSISTED HEATING
SOUTH ORIENTATION OF HOME - Consult any book on home energy efficiency design and you are likely to find that there are inherent advantages to orienting a home directly southward and placing more of the glass on that side. Unfortunately, in subdivision or tract homes, the developer does not have the luxury of such placement strategies since land utilization and street layout are higher economic imperatives. Homes are simply placed with front entrances on the street side for a pleasing neighborhood effect. An added advantage of south orientation is the opportunity it provides for future rooftop solar panel placement.
PRINCIPLES OF PASSIVE SOLAR ASSISTED HEATING
SOUTH FACING HOME DESIGN
In wintertime solar input can reduce heating costs substantially. Of course compensating measures need to be taken in the form of overhangs and other shading to reduce the summer cooling load of this orientation. Following is a view of the south face of our home. It was carefully aligned to be facing true solar south and more glazing was placed on this face. Following are some points to note.
GLASS PLACEMENT - There are ten windows on south face, including the master bedroom door, glass for a total solar input area approaching 200 sqft. 110 sqft is contributed by the two large windows on the left hand side which light a two story sunroom. On a very cold but sunny January day, the upper temperature of this room will approach 90 degrees F. just from solar input. The center two upper windows serve the U shaped open wood stairway to the second floor. The upper three windows on the right light the master bedroom. One window is located in an exit door onto a walkway to the upper deck. The bottom three windows on the right light the dining room.
SUMMER SHADING - Much of the winter heating benefit would be lost to summer cooling load without provision for summertime window shading when the sun's arc is higher in the sky. This design provides that shading in several ways. First, a generous and carefully designed roof overhang provides good shading for the second floor windows including the sunroom. Second, the sunroom includes a Roman shade for the first floor and additionally, the entire room may be closed off on very hot days. And lastly, the upper walkway from the master bedroom to the deck provides shading for the dining room windows.
PERFORMANCE - One estimate of solar heating performance derives from our experience with using the Russian fireplace as the single source of heat prior to the addition of Geothermal HVAC, using electric baseboard only as backup when we traveled away. Normally the Russian fireplace is fired just twice per day. However, even on very cold but sunny January days, we found solar input supported just a single wood firing, usually at night. Two firings would result in too high an indoor temperature when solar input was high.