Passive solar homes are designed to take advantage of local climates by maximizing the energy from the sun to heat and cool the home. In the northern hemisphere, the sun’s path passes through the southern sky on its daily trip west. Therefore, a passive solar home should have the highest percentage of windows on the south side. The sun warms the home in the winter, and shading devices such as overhangs or porch roofs, are designed to block the sun in the summer months to reduce the amount of cooling necessary. Passive solar design creates an energy efficient, comfortable home that reduces energy consumption that saves money as well as valuable resources.

Passive solar design can easily be incorporated into any architectural style given you have the proper site. These design strategies have been used effectively for hundreds of years, you just have to look at early American architectural design and placement on a lot: Stone farmhouses were direct south facing with the largest windows on the south side, their stone barns were closed in the rear and open bays in the front, or south side.  The Anasazi cliff dwellings at Chaco Canyon in New Mexico show how the descendants of the archaic desert culture used passive solar design to take the edge off the bitter cold of high desert winters, while remaining cool for summers.

There are many benefits to passive solar design for the homeowner and the environment. By reducing energy consumption, the homeowner can save money on utility bills and help prevent air pollution from electricity generating plants that burn fossil fuels. Passive solar design elements make a home comfortable year round while bringing in abundant natural light from the increased glass on the southern side. Natural light reduces energy consumption and provides a visual connection to the outdoors.

Incorporating passive solar design into your addition or remodel will lower your heating and cooling bill and save the environment.  Passive solar applications, when included in initial building design, add little or nothing to the cost of a building. Existing buildings can easily be “retrofitted” to passively collect and store solar heat.

 

The most common passive solar system is called direct gain which refers to the sunlight that enters a building through windows, warming the interior space.  During the sunlight hours, this heat can be stored in thermal massThermal Storage Mass incorporated into floors or interior walls made of adobe, brick, concrete, stone, tile or water.  The heat held by the thermal mass will continue to radiate into the space after the sun goes down. Direct gain is the simplest form of passive solar where the house itself acts as a solar energy collector. Thermal storage mass are materials such as concrete floors, interior brick walls, brick pavers, and tile that store heat and regulate interior temperatures both in winter and summer.  Basically your common, everyday home construction materials are thermal storage.

Passive Solar Benefits

  • Saving money. Depending on your needs and the design, you can save from 60% to 100% of your winter heating bill and enjoy natural cooling in the summer.
  • Saving even more money in the future: Does anybody believe the cost of natural gas or electricity will go down?
  • Saving the environment: EPA states a natural gas furnace for a 1000 square foot addition will add 18,976 pounds of CO2 annually to the atmosphere.
  • Living with the natural rhythm of the changing seasons.
  • Increasing comfort. Warmer in winter, cooler in summer, even during a power failure.
  • Enjoying silence: NO operating noise.
  • Visually attractive living environment with large windows and views, sunny interiors with abundant natural light and open floor plans.
  • High resale value.
  • High owner satisfaction.
  • NO maintenance or costs associated with maintenance.
  • Reliability. Operates even during a power failure or if you take a trip!

 

Saving the environment and saving you money – on the cutting edge

There is no conflict between having what you want in an addition or remodel and  passive solar design, and enhances  your living experience by letting in light and becoming part of natural cycles.

Passive solar often costs no more than conventional construction. It’s called “passive” because there are no moving parts, it is simply using the energy of the sun to heat the inside of your home in the winter, and keep it cool in the summer.

Increased south-facing glass area – Allows sunlight to help warm the home in winter months. South- facing windows and skylights receive close to three times as much sunlight as east and west windows in the winter and a third less sunlight in the summer. Sunlight enters south- facing windows and strikes the thermal mass inside the home. The sunlight is converted to heat energy, which heats both the air and thermal mass materials. On most sunny days, solar heat maintains comfort during the mid- morning to late afternoon periods.

Orientation of passive solar construction – Is critical in passive solar design. The passive solar windows must face within 15o of due south to maximize solar gain in winter and minimize overheating in summer. Be aware that magnetic south is different than true south. To find how many degrees they vary at your site visit www.ngdc.noaa.gov/seg/geomag/jsp/Declination.jsp. The house should be designed on an east- west axis so the long side faces south. Trees on the site reduce summer cooling bills, but should not shade south- facing windows in winter: use evergreens on the north to reduce northerly winter winds and deciduous (leaf bearing) trees on the south which when bare in the winter, do not block the sun’s rays, and provide much appreciated shade during summer’s heat.

Energy efficient design – The first step in a successful passive solar home includes proper installation of recommended levels of insulation, air-tight design, and efficient heating and cooling systems. Correcting these conditions increases the thermal efficiency of your home.