DOE Tour of Zero: Green Acres #26 by Greenhill Contracting
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Greenhill Contracting built this 4,208-square-foot home in New Paltz, New York, to the performance criteria of the U.S. Department of Energy Zero Energy Ready Home (ZERH) program.
Photo courtesy of Greenhill Contracting
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The four-story home has a simple, compact, energy-efficient, and cost-effective design that should save its homeowners close to $4,000 annually on energy bills compared to a home built to the 2009 International Energy Conservation Code.
Photo courtesy of Greenhill Contracting
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Insulated concrete form (ICF) thermal blanket walls also serve as the drainage plane so no house wrap is needed. A liquid-applied weather resistant barrier is used for flashing around doors and windows.
Photo courtesy of Greenhill Contracting
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The zero energy home has an 11.76-kW solar electric system meeting all of the home’s electricity needs and contributing to a Home Energy Rating System (HERS) score of -3. In other words, this home is forecast to produce more energy than it consumes.
Photo courtesy of Greenhill Contracting
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ICF thermal blanket construction was used for the foundation walls. The builder sprayed 4.75 inches of closed-cell spray foam directly onto the gravel base to provide a vapor barrier as well as continuous thermal blanket insulation under the slab. Compared to rigid foam sheathing, the closed-cell spray foam has a higher compressive strength, doesn’t break, mitigates the need for a plastic liner under the slab, and forms a tight seal around any piping coming up through the ground.
Photo courtesy of Greenhill Contracting
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A continuous attic thermal blanket at the underside of the roof deck consists of 11 inches of open‐cell spray foam plus 2.75 inches of closed‐cell spray foam that completely air seals the attic, provides an R-69 insulation value, and minimizes the risk of ice dams.
Photo courtesy of Greenhill Contracting
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The home is equipped with an ultra-efficient ground source heat pump that provides heating, cooling, and domestic hot water. On-demand hot water is provided with a central manifold and homerun distribution system that helps minimize the amount of water that is wasted down the drain while waiting for hot water.
Photo courtesy of Greenhill Contracting
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The ultra-efficient (COP 5.7) ground source heat pump uses a central air handler with modulating condensers and a variable-speed electrically commutated motor blower to distribute conditioned air. A balanced fresh air system uses an energy recovery ventilator connected to the air handler to continuously dilute contaminants.