Transcript Chapter 10 Conservation and Environmental Design and Construction

Chapter 10
Conservation and
Environmental Design and
Construction
Links for Chapter 10
Energy-Efficiency Design
Solar Energy Design
Passive Solar Systems
Active Solar Systems
Related Web Sites
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Energy-Efficient Design
• Environmentally friendly relates to materials that
are recycled, from managed farms or earthen
materials
• Be sure to use non-toxic and low-toxic materials for
safer buildings
• Energy efficient individuals have been
experimenting with energy-efficient construction for
decades; their goal is to reduce heating and cooling
cost
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Energy-Efficient Design
• Goals of environmental programs
– Conserve natural resources
– Preserve the earth’s ozone layer
– Create a healthier living environment
– Make housing more economical
– Find better building materials and
construction methods
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Energy Codes
• The purpose of code is to regulate the design
and construction of exterior and interior
materials and equipment
• Exterior envelope is made up of elements of
a building that enclose conditioned spaces
through which thermal energy transfers to or
from the exterior
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Energy-Efficient Construction
• Caulking - Filling in small seams or joints to
reduce air drafts
• Vapor Retarders - Designed to keep exterior
moisture from the walls and insulation
– Most codes require 6-mil plastic over earth
– All seams must be lapped and sealed
– Air-to-air exchanger needed for air circulation
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Energy-Efficient Construction
• Radiant Barriers - Reduce attic temperatures
by stopping heat from radiating through the
attic
• Insulation - Saves energy costs and makes
home temperature more comfortable by
reducing air infiltration and heat loss
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Insulation
• Thermal Resistance - The ability of materials
to slow heat transfer and measured as Rvalue
– R-30 for ceiling
– R-19 for floors
– R-11 to R-19 for walls
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Types of Insulation
• Loose-Fill - Normally made of fibers or
granules and blown into cavities and areas
• Batts and Blanket - Strips of insulation made
of fiberglass or cotton fibers
• Rigid Insulation - Fibrous or plastic foam
sheets of varying thicknesses
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Types of Insulation
• Foam-in-Place - A spray-in foam with a high
R-value made of lcynene
• Insulated Windows - Using a gas or insulated
glass to increase the R-value
– Argon - Colorless and odorless gas
– Low-E - A transparent coating on the glass
– Rated with a U-value (1/U = R)
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Energy-Efficient Construction
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Solar Energy Design
• Using sunlight to produce useful heat energy
• Passive solar uses no mechanical devices to
retain, store, and radiate solar heat
• Active solar uses mechanical devices to
absorb, store, and use solar heat
• Be sure to check local codes before
designing any solar unit in a building
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Roof Overhang
• Winter sunlight that is
lower in the sky helps
warm the home
• Summer sunlight is
blocked from entering
the glass and creating
solar energy
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Passive Solar Systems
• Solar rays enter the house and are absorbed
in structural mass during the day and then
released at night
• Materials may include:
– Metal
– Water
— Concrete
— Masonry
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Passive Solar Systems
• South Facing Glass - Heat
created directly by sun
– Clerestory windows provide
light and heat to second
floor
– Skylights are placed on the
south slope of the roof and
assist in warming in winter
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Passive Solar Systems
• Thermal Storage Walls - Walls
constructed of heat-absorbing material
– Trombe wall is installed a few inches
from a south wall and heat is pushed up
with cool air from below
– Dark water-filled drums are heated with
sunlight during the day and heat is
released at night
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Passive Solar Systems
• Roof Ponds - Containers filled with
antifreeze are placed on a flat roof
– Insulation allows the heated antifreeze to
radiate to the living space
• Solarium - A room placed on the south
side of the house that warms during the
day
– The walls are made of glass
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Passive Solar Systems
• Envelope Design - A continuous cavity is
built around the perimeter of the house
– Solarium is built on the south side
– In the winter this warm air rises
– In the summer the envelope can cool the
house but trees are used to assist
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Envelope Design
Winter Envelope
Summer Envelope
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Active Solar System
• Solar collectors are
used to convert
sunlight into heat by
warming a fluid
• Backup systems are
required if there is a
lack of sunlight
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Active Solar System
• Solar Collectors - Sunlight is caught and
turned into heat
– Collectors are designed to follow the sun’s
path and improve efficiency
• Storage - Water, rock, or chemicals are used
to store the excess heat when it is not
needed
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Active Solar System
• Geothermal Systems - Water from the
ground is circulated through the house to
warm and cool
– Closed-loop systems use a fluid pumped
through polyethylene tubes
– Open-loop systems use water pumped from a
well or reservoir
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Active Solar System
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Active Solar System
• Photovoltaic Modules - Electricity is
produced by sunlight
– “photo” means light and “voltaic” means “to
produce electricity by chemical action
– Both AC and DC electricity is produced
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Active Solar System
• Wind Energy - Turbines are turned caused
by wind created by unequal heating of the
earth
• Hydroelectric Power - Energy is converted
from falling water into electricity
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Related Web Sites
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Alliance to Save Energy - www.ase.org
U.S. Department of Energy - www.doe.gov
OSI Sealants Inc - www.osisealants.com
Sustainable Energy - www.solstice.crest.org
U.S. Green Building Council http://www.usgbc.org/
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