Much has been said about this great insulating Prodoct that has been around for decades and we are now only starting to understand it’s values in it’s insulating properties and the redesigning of the Building Envelope as we have always understood it in the past.
I have noted some writings of the Product so we may all understand how the system works.
Their are more than listed here but way to long in text to show all at once.
Hope this helps many to understand this prodoct a little better than before.
Energy Use/Cost Statistics - Spray Foam to the Rescue
These energy statistics may help you sell spray foam insulation, or help you understand the reasons you should have it in your home. They have been compiled from various sources. Mostly DOE.
- According to the U.S. Dept. of Energy, the average home spends $1,300/year on energy utility costs.
- 1/6th of total electricity consumed in the U.S. is used for cooling, costing $40 billion per year.
- The US Department of Energy (DOE) studies show that 40% of your homes energy is lost due to air infiltration. This air infiltrates the home in the form of drafts through walls sockets, windows and doorways.
- The U.S. Environmental Protection Agency states that common sources for indoor air quality problems include chemicals from building materials and mold.
- California building code efficiency standards (along with those for energy efficient appliances) have saved more than $36 billion in electricity and natural gas costs since 1978. It is estimated the Title 24 standards will save an additional $43 billion by 2013.
- Air ducts. A typical home loses 20 to 30 percent of the air that flows through its ventilation system. The culprit is leaky ductwork. Properly sealed and insulated ducts and joints, especially those routed through attics where temperatures may vary widely from the home’s living spaces, optimize a system’s efficiency. An insulation value of R-6 is recommended for ductwork
- Energy Star-qualified homes are independently verified to be at least 30 percent more energy efficient than homes built to the 1993 national Model Energy Code.
[FONT=Arial]Foam Insulation for Attic Spaces [/FONT]
[FONT=Arial][FONT=Arial]Spray Polyurethane Foam Insulation can be used in two common ways to insulate your attic space and protect your home from other weather and moisture related damages.
Spray Foam Insulation in the Attic Floor (Vented Attic Spaces)
The method of use for spray foam in the attic is often dictated by the building science and design principles your architect and/or builder subscribes to. In a traditional vented attic, insulation is used on the attic floor to insulate the ceiling from the seasonal heat and/or cold. Spray foam is used where traditional fiberglass batts, or cellulose is used; between the floor joists. The rest if the attic is left un-insulated and highly vented through gable, soffit, and ridge vents in the roof structure. This type of engineered system is the most common throughout the US, but may not be the most effective.
Spray Foam Insulation in the Attic Floor (Non-Vented Attic Spaces)
In this application, considered the most effective, by most of the SPF industry, the foam is sprayed directly to the underside of the roof between the joists, down around the rim and into the soffit areas, on the gable wall ends, and effectively sealing off and insulating the entire attic space from any air infiltration.
The traditional practice of insulating the underside of the roof in the attic has raised much debate in the building industry because “standard” roofing and design techniques call for the attic to be
[FONT=Arial]ventilated in order to reduce moisture problems and heat build-up in the hot summer months.
However, a vented attic situation it will become approximately 130-degrees in the summer. There’s no reason for your air-conditioning and vent-ductwork to have to work in that type of severe conditions. There is also opportunity for moisture to form due to condensation on these appliances.
By applying spray foam directly to the underside of the roof deck, it now insulates the attic space from the extreme heat that once radiated thorough the hot shingles sheathing and roof. The severe temperatures no longer exist in the attic. In short, the attic now becomes a “conditioned” space of the house that is just as comfortable as any other room in the home.
Most builders and designers will tell you that this system is no good because wood needs to breathe and that the shingles on your roof will now overheat, get too hot and curl off.
[FONT=Arial]A roof system insulated with spray foam reduces energy several ways. Energy loss from ducts located in the attic is essentially eliminated. The top of the building is much tighter resulting in less infiltration and infiltration, so excess moisture isn’t pulled into the attic. Infiltration through the ceiling is also reduced. In addition, the attic temperature is lower, which further reduces energy loads.
[FONT=Arial]The benefits of including the attic in the insulated space are:
- Duct leakage and heat loss/gain from ducts is much less of an issue.
- Air sealing is easier in the roof that in the ceiling.
- Dust and loose insulation are less likely to migrate down to the living space.
- Tests show energy costs are lower when the attic is sealed.
Hope some of this information helps some.