Heating and cooling energy represent the biggest single factors. Today in the U.S., residential structures use 21% and commercial structures use 17% of the total energy produced. It is a well documented that it is cheaper and easier to conserve energy than it is to generate new energy. The importance of saving energy in building construction cannot be over stated: today’s efforts at reducing pollution, dependence on foreign oil, and global warming are almost completely dedicated to the generation side of the issue. These high-performance homes featured structural insulated panel walls and roofs, roof-top solar photovoltaic systems, and other energy efficient technologies that helped the homes approach DOE’s goal of net-zero energy use. In 2002, ORNL teamed up with the Structural Insulated Panel Association (SIPA) and the DOE to create five innovative net-zero energy buildings. SIPs have been instrumental in the creation of many zero-energy buildings that produce as much energy as they consume through solar photovoltaic cells and a high performance SIP building envelope. When combined with other high-performance systems, SIP homes can reduce annual energy use by up to 50 percent or more. SIP homes have proven to reach these levels of air tightness consistently enough for the EPA to waive the required blower door test for homes with a complete SIP envelope to receive an ENERGY STAR rating. Stick-framed homes of similar size in the same subdivision averaged blower door test results ranging from 0.20 to 0.25. SIP-research homes built by ORNL were measured to have infiltration rates as low as 0.03 natural air changes per hour (ACH). Using a specially designed fan to negatively pressurize the structure, Home Energy Rating System (HERS) technicians can measure the amount of air leakage in the home and use this information to size HVAC equipment or apply for an ENERGY STAR qualification. Follow this link to see the full report.Īir leakage in homes is measured by using a blower door test. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL) have shown a SIP room to have 90 percent less air leakage than its stick-framed counterpart. Additionally, fiberglass and other insulating materials used in stick-framing are subject to gaps, voids, or compression, causing further degradation in thermal performance and drafts.īuilding with jumbo SIPs results in fewer joints and is an easy way to build a very air-tight structure. ![]() When the whole-wall R-value is measured, SIP walls outperform stick-framed walls where studs placed 16 or 24 inches on center cause thermal bridging and result in energy loss. A typical stick-framed home averages a framing factor ranging from 15 to 25 percent, while a SIP home averages a framing factor of only 3 percent. The more framing, the higher the framing factor and the more energy is lost due to thermal bridging. ![]() ![]() The percentage of area in a wall assembly composed of sawn lumber is classified as a wall’s “framing factor.” The framing factor is a measure of thermal bridging. SIPs enable structures to be assembled with minimal in-field framing. The insulating core of a structural insulated panel provides continuous insulation. EPS foam plastic provides top-performing structure and insulation for this building component. PorterSIPs use one pound density expanded polystyrene (EPS) foam plastic as the core. SIPs use their plastic foam core as structure as well as insulation. Green homes have envelopes with superior insulation and are essentially airtight.Energy Efficient Building Envelopes SIPs help to minimize environmental impact The design, engineering, and construction of your home’s envelope, including its strength, insulative qualities, it being airtight and acting as a vapor/moisture barrier are CRITICAL to a green home’s energy performance, indoor air quality, comfort, and health. It is also the spaces you don’t want to be drafty or have allergens and pollution coming into your home from the outside. ![]() The conditioned spaces are the parts of your home you use energy to heat and/or cool. More precisely, it is the part of your home that separates your home’s inside conditioned spaces from the home’s non-conditioned spaces (like an attached garage, porch, deck and sometimes the attic) and the outdoors. Your home’s envelope elements like your home’s foundation, exterior walls, framing, insulation, air sealing, vapor barriers, wind barriers, drainage planes, exterior windows and doors, attic floor and/or roof. A building envelope is also called a thermal envelope or sometimes just an envelope. It is also a key element in making your home a healthy home. Your Home’s “Building Envelope” is arguably the most important aspect of making a home energy efficient and comfortable. Green Home Building Certification Programs.
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