Project Description:
The Torcellini Residence, a three-bedroom 1920’s bungalow style home, is designed to emphasize durability, reduce consumption, and improve indoor air quality (IAQ). Steven Winter Associates, Inc. (SWA) acted as the HERS rater and provided ENERGY STAR v3.1, Indoor airPLUS, and the DOE Zero Energy Ready Homes certification support. Entered into the 2016 CT Zero Energy Challenge, the Torcellini Residence won the Lowest Construction Cost category ($83/sf), and was involved in a tie for Overall Winner.
Relying on passive design, the home’s orientation maximizes solar gain during cold months while generous overhangs provide summer shading. Using CO2 as refrigerant, a Sanden SanCO2 air-to-water heat pump provides heat for the radiant floors and the domestic hot water. As an alternative to typical refrigerants, CO2 has no ozone layer depletion and minimal global warming impact. Cooling and supplemental heat are provided by a ductless mini-split heat pump. Double stud walls with 12” of blown in batts (BIBS) are R50 and the cathedral ceilings with strapping on rafters are R55 (BIBS) while the attic area is over R80. Solar panels are clip mounted on a 30 degree metal roof system providing 9.4kW of renewable energy and reducing the Home Energy Rating System (HERS) Index from 35 to 2. Energy efficiency is further enhanced by LED lighting throughout the home. Lighting fixtures, electrical plates and kitchen cabinets were painstakingly reclaimed to meet the aesthetic and limit the amount of new material produced for finishes.
To promote energy independence and resiliency, the home has a root cellar and will be outfitted with a battery storage system for times when the grid is down. Furthering their commitment to low impact living, the Torcellini’s produce much of what they consume through vegetable gardens, fruit trees, and farm animals such as turkeys, chickens and pigs. They also have a zero VOC approach to everything that’s brought into the home from the mineral paint on the walls and plant based floor finish to the cleaning products used daily.
Building Type Summary:
Other Awards:
Entered into the 2016 CT Zero Energy Challenge, the Torcellini Residence won the Lowest Construction Cost category ($83/sf), and was involved in a tie for Overall Winner.
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Site description:
The site was selected because of excellent solar access, yet well protected from the north and the west by the landscape.
Materials:
- Lighting fixtures, electrical plates and kitchen cabinets were painstakingly reclaimed to meet the aesthetic and limit the amount of new material produced for finishes.
- Long-life recyclable metal roof made from partial recycled materials (25% recycled content)
- Hardwood floors assembled from short lengths and seconds from a local hardwood flooring manufacturer finished with Tung oil and citrus solvent.
- Trim made from on-site wood from the lot clearing.
- Cement and coal ash based trim and siding with factory applied finishes
Energy Highlights:
- Passive design
- Air-to-water heat pump for providing heat for radiant floor and hot water
- Ductless mini-split heat pump for cooling and supplemental heating
- 9.4kW PV System
- LED Lighting throughout the home
- Root cellar outfitted with battery storage system for times when the grid is down.
HERS Index:
Energy Storage type:
Battery Storage
Subslab assembly:
Subslab has R-Value of 10.
Foundation wall assembly:
Basement root cellar thermally isolated from house including dedicated ventilation system to maintain constant temperature of less than 55⁰F.
Above grade wall assembly:
There is 12 inches of blown in blanket insulation in the cavity between double stud walls. The total R-Value is 50
Flat attic assembly:
Attic has blown in blanket system (BIBS) with R-value of 80.
Cathedral ceiling assembly:
Cathedral ceilings with strapping on rafters have blown in blanket system (BIBS) with R-value of 50.
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Design for Adaptability:
- 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.
- Separate water system for toilets to allow for deep well water or future rain water collection
- Ability to connect portions of the house to battery systems as costs decrease for these systems.
- Wiring design is flexible to accommodate future DC appliances and electrical systems that could be directly connected to PV system.
Published References:
Special architectural measures:
- Relying on passive design, the home’s orientation maximizes solar gain during cold months while generous overhangs provide summer shading.
- Passive solar design with sunroom that can be isolated from the house.
- Compact square design to minimize wasted space.
- 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.
Energy Strategies:
Relying on passive design, the home’s orientation maximizes solar gain during cold months while generous
overhangs provide summer shading.Cooling and supplemental heat are
provided by a ductless mini-split heat pump. Double stud walls with 12” of blown in batts (BIBS) are R50 and
the cathedral ceilings with strapping on rafters are R55 (BIBS) while the attic area is over R80. Solar panels
are clip mounted on a 30 degree metal roof system providing 9.4kW of renewable energy. Energy efficiency is further enhanced by LED lighting
throughout the home.
Energy Use and Production Documentation:
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Storage Strategies & System Details:
Root cellar outfitted with battery storage. Ability to connect portions of the house to battery systems as costs decrease for these systems.
Window Description:
Typical double-hung windows were used for architectural appearance without a substantial decrease in performance. On a sunny winter day, the house requires minimal heating from the HVAC system.