DSM Pocket Guidebook Volume 5: Renewable and Related ... - NREL

R E N E W ABLE B R I E F 1 5
(update to RESIDENTIAL BRIEF 8)
PASSIVE SOLAR DESIGN
• TECHNOLOGY DESCRIPTION
A passive solar building is designed to maximize useable solar heat
gain in the winter and minimize heat gain in the summer to create a
comfortable interior living environment. A p a ssive solar design is site
specific, varying with the local climate and building type. System
components to increase heat gain may include south-facing windows
and moveable insulation, walls or floors that use masonry or water to
store heat, and a sunspoce or greenhouse. System components to
prevent heat gain include overhangs or shades, landscaping, and vents.
Good passive design involves a balance of conservation and solar
design features. Conservation makes the passive solar system's job
easier; likewise, passive solar features reduce the need for auxiliary
heat.
U.S. utdities are beginning to recognize that programs focused on new
construction ore a popular way to capture what is otherwise a "lost
opportunity" for gaining energy efficiency over and above current
building practice. By employing passive solar design and encouraging
no-cost steps such as siting for solar access and natural cooling, utilities
con significant reduce a building's heating and cooling requirements.
Costs and benefits for residential passive solar systems ore shown in
Table R-25 .
• DEFINITIONS AND TERMS
ANNUAL SOLAR SAVINGS The annual solar savings of a solar
building is the energy savings oHributoble to a solar feature relative to
the energy requirements of a nonsolor building.
DIREO GAIN In direct-gain buildings, sunlight directly enters the
home through the windows and is absorbed and stored in massive floors
or walk. These buildings ore elongated in the east-west direction, and
most of their windows ore on the south side. The area devoted to south
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