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A. Tankless Water Heaters
Gas-fired tankless water heaters are about 20% more efficient than
gas-fired water heater tanks because they have more efficient burners
and avoid stand-by loss. For best efficiency, a tankless water heater
should be located as close as possible to the end use.
B. Central Vacuum System
Central vacuum systems have a motor and dust receptacle
which is fixed. It’s usually installed in the garage, basement
or utility room to minimize exposure to motor noise and
emissions. The vacuum nozzle is attached to a hose that
can be plugged into various ports throughout the house.
Vacuum exhaust should be vented to the outside to avoid
dust re-circulating inside the house. Suspended dust
can trigger asthma and other allergic reactions.
C. ENERGY STAR® Rated Windows
Window heat loss is described by U-value. Manufacturers
use testing and reporting standards established
by the National Fenestration Rating Council. The U-value
is on a sticker attached to each window. Because windows
typically lose heat seven times faster than walls, the ENERGY
STAR rating also limits window area to no more than 21% of
conditioned floor area.
D. Efficient Ductwork Design and Sealing
Typical forced air heating systems can lose up to 30% of heated air before
it reaches the house. Sealing and testing ducts reduces this loss to 6% or
less. Return ducts that pull air from the house to the furnace are under
negative pressure, so any leakage in a return duct pulls air in. Returns
typically run through attics or crawlspaces where air is contaminated by
dust, soil gasses and moisture, so sealing return ducts reduces these
contaminants. Finally, sealed ducts deliver conditioned air more
effectively and increase comfort.
E. Low VOC Paints, Adhesives and Finishes
Water-based low-VOC (volatile organic compounds) paints and other
low-VOC materials reduce harmful substances in the air for both builders
and home owners. For most applications there is little or no difference in
performance.
F. Composition Roof and Fiber Cement Siding
Longer-lasting shingles and siding are better for the environment than
cheaper, less-durable products. Durable materials lessen demand for
scarce resources, and generate less waste for local landfills. For instance,
using 40-year warranted shingles instead of the typical 20-year shingles
can reduce waste and demand for new materials by 50%. Durable
materials also avoid the energy costs of replacing shorter lived products.
Durable materials are a better investment in the long run because they
require less maintenance and repair. Typical composition
shingles are made using asphalt, a petroleum-based product. Their manufacture uses
significant energy, and they release VOCs when installed. VOCs pose a health risk to
workers and contribute to ground level ozone, a major component of smog.
All other things being equal, the more durable the product, the better its
overall resource efficiency.
G. Kiln-Dried Framing Lumber
This lumber is moisture tested to help prevent future wood mold
problems in the home’s walls.
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H. Increased Insulation
This home is insulated to ENERGY STAR standards and has been inspected
to ensure minimal gaps, voids, and compression. This results in a better
performing wall assembly with less risk of moisture problems. When
insulation is compressed, or doesn’t fill a cavity, warm air can escape more
easily and condensation can occur within the wall.
K. Photovoltaic Panels
Photovoltaic (PV) panels convert the sun’s energy to electricity. PV
systems can be independent, or connected to the utility distribution
system. A residential, utility-tied system typically includes panels (PV
modules) and an inverter/controller. PV systems don’t generate pollution,
and can lessen the utility’s need to build large power plants.
L. Pervious Surfaces/Pavers
Groundwater is replenished by rainwater that soaks into the ground.
Impervious surfaces such as driveways, sidewalks and patios interrupt the
natural recharging of ground water. Pervious surfaces such as paving
stones allow the surface water to percolate into the ground on site.
Pervious surfaces reduce the potential for flooding, both on and off-site,
by allowing more water to soak directly into the ground. Also, using
pervious surfaces instead of impervious surfaces is more resource
effcient, since it takes less material to cover the same area.
K. Construction Site Recycling
Wood, drywall, and other materials are separated on-site for recycling,
reducing impact on the environment.
M. High Efficiency Heating & Cooling Equipment and Mechanical Ventilation
High effciency equipment improves HVAC performance
and lowers operating costs. These models also have sealed
combustion, draw air from outside and are less vulnerable
to back-drafting of combustion gasses. Mechanical ventilation
delivers controllable fresh air, ensures better indoor air
quality, and helps remove moisture.
Zonal Pressure Relief
Forced-air heating systems use large blowers to move
conditioned air through the house. Ideally, all of this air
flows smoothly through the house and then to the central
return. Unfortunately, interior doors block air flow and
create severe pressure imbalances—air gets “bottled up”
behind closed doors. Pressure problems can also cause
naturally-vented combustion appliances to back-draft,
which brings harmful flue gasses into the house. Systems
with adequate pressure relief provide better safety, comfort
and efficiency.
LED Lighting
The light-emitting diode (LED) is a new light source that offers high
energy efficiency, dimming capability, no mercury content, and
potentially very long life. The LED lights installed in this house save 80%
or more electricity compared to incandescent lights.
Water Efficiency
Toilets consume about 30% of all clean indoor water, more than any other
plumbing fixture. Dual flush toilets use two flush modes: the first mode
uses the full 1.6 gallons per flush for flushing solid waste; the second
mode uses fewer gallons per flush (usually 0.6 - 1.1 gallon) for flushing
liquid waste. Similarly, low flow fixtures like shower heads provide a
comfortable but reduced flow of water, reducing water consumption.
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