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Design Principles of Passive Solar Homes
This section introduces the basic design principles. Current trends in housing, such as expansive glass areas, daylighting, sunrooms, great rooms, tile floors, fireplaces, and open floor plans fit well into passive solar designs. Effective designs reduce heating and cooling bills and provide greater comfort.
Heating Season
In the winter months, three primary elements interact to provide a significant portion of a home’s heating needs:
 energy efficiency features including effective insulation, airtight construction, and efficient HVAC systems, minimize the demand for heating;
 increased south- facing windows bring additional sunlight into the home which can be captured as heat energy;
 thermal mass can supply a means to store heat inside the home. Concrete or tile floors; walls made of masonry materials such as brick, stone, concrete; a masonry fireplace; or water- filled containers all provide thermal mass for heat storage and can be incorporated to meet the aesthetic requirements of the space.
Cooling Season
In summer months, passive solar homes in North Carolina must compensate for the hot, humid climate and the large amount of heat that can come into the home through windows. The true challenge of passive solar design is to ensure low summer cooling bills compared to those of a similar, standard home.
Many passive solar homes have significantly lower cooling bills because they:
 have energy efficient features – high insulation levels, airtight construction, and effective air conditioning system design and installation;
 have few, if any, windows on the east and west minimizing solar gain in the mornings and afternoons;
 provide shading for south- facing windows;
 incorporate thermal mass to balance temperature extremes;
 can be ventilated during milder outdoor weather with open windows and fans, which help maintain indoor comfort.
Passive Solar Heating Design Components
1. Orientaion- long axis facing south.
2. Glazing- South windows let sunlight into the building in winter and can be shaded effectively in summer.
3. Thermal mass- Tile- covered slab floors, masonry walls, and water- filled containers store solar heat and help save energy all year.
4. Heat distribution- Openings and room layouts that aid movement of solar heated air from passive solar rooms to other actively used rooms in the home.
Natural Cooling Design Components
1. Window shading- Over­hangs,
shutters, blinds, shade screens, curtains, and landscaping shade un­wanted
sunlight in summer.
2. Ventilation- natural breezes through windows on opposite sides of the house, ceiling fans, whole house fans, and space fans keep the house more com­fortable
during non- heating and cooling periods of the year.