
THE BEST TIME TO THINK ABOUT ENERGY EFFICIENCY IS IN THE
PLANNING STAGE. THE MOST EFFICIENT HOMES TAKE ADVANTAGE
OF SITE, DESIGN, ENERGY EFFICIENT MATERIALS AND THE LATEST
TECHNOLOGY.
SITE – Make the most of your site’s natural features, considering
sun and wind. Especially in cold climates, plan a good amount of
southern exposure, since the south side receives almost three
times the sunlight as other sides.
Minimize glass on the north, east and west, but remember to let
in some light to balance. Deciduous trees on the south block hot
summer sun, but are leafless in the winter to let the sunshine in.
In hot climates, shield the house from effects of direct sunlight,
both for comfort and for air-conditioning efficiency. Overhangs,
porches, shade trees and windows in the path of air flows can
help prevent overheating in the summer.
DESIGN – The less space you have to heat, the better. Determine
exactly how much space your family requires. Then arrange rooms
in relation to the sun, putting light and heat where you need them
most: the breakfast nook in early morning, the kitchen throughout
the day, and the family room during the late afternoon. Consider
locating sleeping and working areas to the north, where cooler
temperatures are preferred. A kitchen will generate its own heat.
If at all possible, avoid placing an entry to the north, or at least
keep cold air from entering with an air-lock entry.
MATERIALS & TECHNOLOGY – Fifty to seventy percent of the
energy used in the average American home is for heating and
cooling. The use of energy-saving materials is essential if you
want to substantially reduce energy costs.
The crucial role of thermal insulation:
Insulation not only saves money, it can make your home more
comfortable. Insulation helps maintain a uniform temperature
throughout the house. Walls, ceilings and floors will be warmer
in the winter and cooler in the summer. Fewer drafts mean your
home will remain comfortable at lower thermostat settings.
Thermal insulation also acts as a sound barrier keeping noise
levels down.
The insulating ability of the components of a home, whether in the
roof, walls, windows or doors, is most often measured in terms of
R-value, or the resistance to heat flow. The higher the R-value,
the greater the insulating power.
Tyvek® house wrap improves energy efficiency:
Tyvek® acts as a windbreaker over insulation to help stop drafts
and prevent air movement in the insulation cavity, thereby
protecting R-value. Air movement can account for 30-40% of a
home’s total heating or cooling loss. Tyvek® is placed on the
exterior or cold side of the insulation, over the sheathing.
A vapor barrier – heavy polyethylene sheathing – is placed on the
interior or warm side of the insulation. Equally important, it keeps
moisture away from the insulation, which would destroy its R-value.
Low-E insulated windows
Low-E glass uses a hidden metallic coating and Argon-filled cavity
to provide maximum energy efficiency. It allows sunlight to enter
and heat your home. But when the heat tries to escape, the
coating reflects it back into the room. As much as 90% of the
radiated heat is retained, reducing heat loss up to 50%. In summer
or in hot climates, the reverse is true: Low-E blocks the heat from
entering the home.
Insulated entrance doors
Your best choice is an insulated door with a high R-Value. Pre-hung
insulated door systems come complete with weather stripping for a
tight fit with no gaps to waste energy. Choose an insulated door for
your garage if it doubles as a winter workshop or is attached to your
home. |