Page 35 - The Homeowner's Handbook 2017

Exteriors / Roofing / Structure / Insulation / IAQ / Windows & Doors / Heating & Cooling / Lighting / Appliances / Plumbing / Finishes / Cabinets & Tops / Alternative Energy

with high solar gain, low-E glass. Keep this in mind when you are Glossary of Terms
assessing the “first cost” of new windows.
Know the Lingo
COMFORT
Know the Science ■ ■ Air Infiltration: The amount of air that passes between a
For homeowners, how comfortable a house feels can be just as window sash and frame, measured in cubic feet per minute
important as its energy efficiency. An older window with a lower per square foot of frame area.
glass temperature feels colder because more heat is radiated from a ■ ■ Argon Gas: A colorless, odorless, inert gas that fills the
person’s body to the window. otherwise empty space within an insulating glass unit.
Cold glass can also create uncomfortable drafts as air next to ■ ■ Efficient Windows Collaborative: Organization that
the window is cooled and drops to the floor. This sets up an air provides detailed reports and studies on the value of
movement pattern that feels drafty and accelerates heat loss. using high-performance windows. Visit the website at
High-performance windows with lower U-values will result in www.efficientwindows.org for more information on the
a higher interior window temperature in winter and thus greater studies cited in this article.
comfort. Proper installation along with weatherstripping designed ■ ■ Insulating Glass (IG): Glass units constructed of two or more
to seal tightly will also improve comfort by reducing cold air leakage. glass panes separated by a hermetically sealed space.
During the summer, direct sunlight strikes people and surfaces, ■ ■ Low-Emissivity Coating (low-E): Low-E finishes reduce
creating overheating and discomfort. Windows with low solar heat energy transfer through insulating glass units, and thereby
gain coefficients will reduce the solar radiation coming through the achieve one of the highest levels of energy performance
glass. That’s where low-emissivity (low-E) glass comes in—reducing possible for glass.
heat gain while still providing sufficient light and view. ■ ■ Solar Heat Gain Coefficient (SHGC): Measures the fraction
of solar energy admitted, and indicates how well the product
LESS FADING AND CONDENSATION blocks heat caused by sunlight.
Block the Rays ■ ■ U-Value: The escape of BTUs per square foot per hour, per
High-performance windows with new glazing technologies make degree Fahrenheit.
homes more comfortable. They create warmer interior glass surfaces, ■ ■ Warm Edge Technology: The use of low-conductance
reducing frost and condensation. High-performance windows with spacers to reduce heat transfer near the edge of
warm edge technology and insulating frames have such a warm insulated glazing.
interior surface that condensation on interior surfaces is significantly

INSULATED GARAGE DOORS

N MOST MODERN HOMES, garage doors are
the single largest opening; in homes with an
attached garage and/or a heated garage space,
I this large opening is a significant source of
energy loss, translating into higher utility bills and a
larger carbon footprint.
Although you may not be able to tell the difference from PHOTO: PRESTIGE PRODUCTS, DENVER, CO
appearances alone, eco-friendly or green garage doors differ from
traditional garage doors in that they generally contain enough
insulation to provide an R-value of 12 or greater and contain
recycled and/or recyclable materials to minimize their impact on Hidden Beauty. Insulated garage doors can also have a
the planet. Recycled wood fibers as well as partially recycled steel traditional look.
are common materials used to produce green garage doors; these provides a high R-value without excessive thickness. When combined
products have a long lifespan and are designed to require little or no with quality weather striping, green garage doors can significantly
annual maintenance such as the painting or staining which is needed reduce the loss of heated or cooled air which may have passed
with some older garage door models. through the shared wall of your home (in the case of an attached
Since one environmental aspect of a green garage door is garage) or heat that is generated by a separate heater or furnace if
energy savings, most models are filled with an insulating foam which your garage space is also conditioned during a portion of each year.

www.greenbuildermedia.com The Homeowner’s Handbook 2017 GREEN BUILDER 33

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