2015 Challenge Participant:
Applicant: Paul Torcellini
Project Address: 76 Weeks Road, Eastford, CT 06242
Bdrms./Sq. Footage: 3 BD - 3,597 sq ft
General Project Overview:
The main goal of the house is to create a self-sustaining home that is energy-efficient, durable, and healthy. This is being done in the context of a traditional bungalow style house (reproduced from a circa 1925 house) to exemplify the simple elegance of housing design. In addition, the site is being designed to provide most of the food for the family to minimize the energy and environmental aspects of the food industry. The home will reduce the impact of the family, hopefully, for many generations to come. The site was selected because of excellent solar access, yet well protected from the north and the west by the landscape.
The key was to make integrated design solutions that looked at minimizing energy consumption and future maintenance needs.
Due to the strong commitment of the owners to sustainable architecture, every aspect of the material selections and energy consumption details were carefully evaluated with an eye on constructing to Energy Star and DOE Zero Energy Ready standards. The goal is to meet the DOE standardized definition of a zero energy building published in August 2015.
The owners are particularly attentive to air quality creating a house that is tightly constructed providing controlled fresh air through an air-to-air heat exchanger as well as providing for effective natural ventilation circulation patterns through the house. Many zero-VOC and low-VOC products are being selected including insulation, natural paints, and floor materials.
- Basement root cellar thermally isolated from house including dedicated ventilation system to maintain constant temperature of less than 55⁰F.
- Compact square design to minimize wasted space.
- Salvaged metal kitchen (1950’s).
- Passive solar design with sunroom that can be isolated from the house.
- All LED lighting for a total house-wide install capacity of less than 600 watts.
- Radiant floors that enable the space temperature to feel like 70⁰F when the actual setpoint is 63-65⁰F.
- Air-to-water heat pump, using CO2 as a natural refrigerant, providing heat for radiant floors and domestic hot water.
- Air-to-air heat pump to provide cooling and dehumidification and supplemental heat
Orientation and Envelope (Windows, Insulation, Framing):
- 12 inch wall cavities with R-50 fiberglass, blown-in insulation
- Engineered floor system to minimize material waste (both in manufacturing and installation).
- Due south orientation (set by shadow calculations) with passive solar sunspace.
- Window glazing tuned to orientation to maximize solar gain when needed and reject when not needed. Typical double-hung windows were used for architectural apperance without a substantial decrease in performance. On a sunny winter day, the house requires minimal heating from the HVAC system.
- Calculated overhang lengths to naturally shade a large fraction of the glass in the summer while allowing low-summer sun to enter the space.
- Open floor plan designed to maximize natural ventilation as well as air circulation patterns without fans.
Heating, Cooling, and Hot Water:
- Air-to-water heat pump system providing heat for radiant floors and domestic hot water. System uses CO2 as refrigerant to minimize the environmental impact of space and water conditioning.
- Air-to-air heat pump to provide cooling and dehumification and supplemental heat.
- Plumbing system designed to minimize hot water runs to decrease energy and water use.
- Heat pump hot water heater centrally located to minimize plumbing runs for water efficiency.
- Hydronic, radiant floor system zoned to minimize conditioned area and to designed to provide thermal comfort with cooler temperatures (winter); Typically the setpoint can be 5-7 degrees cooler with radiant floors.
- Twelve zones or radiant help to self-balance and provide individual room control.
- Energy Star rated air-to-air heat exchanger with exhaust in the kitchen and bathrooms and supply to the bedrooms.
- Wiring design is flexible to accommodate future DC appliances and electrical systems that could be directly connected to PV system.
- Ability to connect portions of the house to battery systems as costs decrease for these systems.
- Rough-in wiring for future electrical vehicles (to be considered when current vehicles reach end-of-life.
- Circuit design to accommodate demand response.
- All LED lighting for a total house-wide installed capacity of less than 600 watts.
- Electrical boxes with gaskets were used on all exterior walls to prevent air infiltration at the box locations.
- 9.4 kW of photovoltaics mounted at a 30 degree angle directly mounted to a standing seam metal roof. System includes 4 MPPT inverter configuration to minimize any shading impacts.
- Infrastructure to allow for direct connection of wood-fired hot water to hot water loops (heating and domestic hot water). Ample wood is available on-site as a possible on-site renewable resource.
Resources Sustainability Features:
- Separate water system for toilets to allow for deep well water or future rain water collection
- Ultra-low flush toilets (1 pt./flush)
- Segregated gray and black water drain plumbing.
- Rainwater diversion from standing seam metal roof for irrigation (avoids contamination possible from asphalt roofing materials).
- Long-life recyclable metal roof made from partial recycled materials (25% recycled content) designed to easily accommodate PV system and rain water collection systems.
- Extra-long overhangs to shed water away from foundation.
- Cement and coal ash based trim and siding with factory applied finishes.
- Hardwood floors assembled from short lengths and seconds from a local hardwood flooring manufacturer finished with Tung oil and citrus solvent.
- Trim to be made from on-site wood from the lot clearing.
- Landfill trash was minimized by careful sorting of all waste materials. Scraps were sorted and used for blocking and plumbing supports. Any burnable waste was seperated for kindling wood. All cardboard, beverage containers, and metals were seperated and recycled.