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Structural Insulated Panel Systems
One of the best methods for building a
highly energy efficient home is to use an insulated panel system. These may be
structural (structural insulated panels are called SIP's) or non-structural. The
latter are used to enclose timber frames. SIP's are used for non-timber framed
additions in a hybrid home. The panels are constructed of foam insulation --
expanded polystyrene (EPS) or polyurethane -- sandwiched between two layers of
7/16-inch oriented strand board (OSB). The panels employ a tongue and groove
connecting system that forms an interlocking, uninterrupted insulation barrier
against heat loss, heat gain or air infiltration.
Insulated panels have proven to be much
more energy efficient than stick framed wall and roof systems. In a stick framed
wall, the wood studs result in a cold spot at regular intervals, since wood is
not a good insulating material and has a R-Value of about 1 per inch. This means
that each 2 X 6 stud provides a mere R-6 of insulation. In addition, the fiber
glass batts tend to have gaps, to get crimped or compressed, and to loosen
around electrical outlets and pipes. These cause drafts and greatly reduce the
overall insulating value of the batts. So although the batts may be a R-11 or a
R-17, actual whole wall performance will be much lower.
Panels have a continuous foam core that
does not allow for drafts, cold spots, and reduced insulation value. As a
result, they have much better whole wall performance,. They enable you to
purchase a smaller HVAC system from the outset, providing immediate savings. You
continue to save from 40%-60% on heating and cooling costs, year after year. At
the same time, your home will be much cozier and draft-free in the winter and
cooler in the summer.
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The above diagram shows the roof panel to panel
connection stardard for the Insulated Panel Systems utilized by Goshen Timber
Frames.
This diagram shows the wall panel to panel
connection.
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Energy Recovery Ventilator
With the energy efficient timber frame, we recommend
installation of an energy recovery ventilation system (ERV). An energy recovery
ventilation system will improve the indoor quality of the air and keep the
humidity in the home at a constant. In any climate, this is beneficial to help
control indoor relative humidity. In the heating season, an ERV will preserve
essential moisture in the home while keeping it below excessive levels. During
cooling season it minimizes the added moisture that the incoming airflow may
contain.
An energy recovery ventilator continuously exhausts
stale, polluted indoor air and replaces it with fresh outdoor air. Energy from
the indoor air (warm air in winter, cool air in summer) is extracted and
transferred to the fresh incoming air so there is little energy loss.
The energy recovery ventilator system will be installed
by your local heating and air conditioning contractor and be an integral part of
your heat and air conditioning system. In heating climates, remember heating the
air may dry it to below a desired humidity level, in which case added
humidification may be needed.
The use of an energy recovery ventilation system in your
timber frame home will enhance the indoor air quality and humidity levels to the
most comfortable zone for you and your family. |
Energy Efficient Windows
The energy efficiency of the walls and roof are not the only R-values today's homeowners need to consider. Windows let in
more than just light and scenic views. The wrong choice in windows and doors can
negate much of the energy efficiency a well-informed homeowner has been able to
gain through an effective insulation system. In addition to their respective
insulating properties, any quality window or door greatly reduces the
infiltration of outside noises.
Keep in mind that a thermal window merely means it is
two panes of glass, which has an R-value of no more than 2. There are glazing
options available that more than quadruple that R-value. In addition to keeping
out the cold there are also options that address specific needs. A window in a
north-facing wall does not have the same job to perform as one in a south-facing
wall. By carefully selecting from the various glazing options homeowners can
fine-tune their homes.
For example, a glaze to produce Low E (low emissivity)
glass not only increases a window's R-value, but also blocks out ultra violet
rays, thereby protecting your timber frame, and the furniture, rugs and
draperies.
Another glazing option eliminates unwanted heat gain.
While passive solar is the least expensive method of heating a home, gaining
heat is desirable only in winter and that bank of south facing windows will
still be there come summer. It is, for example, usually preferable to place
skylights on north facing roofs, thereby enjoying the sunlight year round
without suffering from unwanted heat in the summertime. Remember that a window
that is too cold (or too hot) to sit near takes away from the usable living
space in your home.
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Quality Craftsmanship
Goshen Timber Frames builds the timber frames with quality craftsmanship and when using the energy-efficient stress skins (SIPS) in the wall and roof systems, creates a really energy efficient ("tight") house. Keeping in mind also the timbers used in the frame are, in most cases, "green timbers". They have a high moisture content and will continue drying for several years. The drying process does not affect the stability of the structure or the joinery. |
 Resources
In order to promote energy efficient
windows, doors and sky-lights, a voluntary partnership has been formed between
DOE, EPA and the fenestration industry. They place an energy star label on
windows that meet energy efficiency performance standards. You can get more
information by calling (888) 782-7937 or going to www.energystar.gov/products/windows.
Other helpful organizations include the Center for Resourceful Building
Technology in Missoula, MT: (406) 549-7678 or www.crbt.org and Efficient Windows Collaborative in Washington, DC:
(202) 530-2245 or www.efficientwindows.org. |
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