2013 Challenge Participant:
Applicants: Jamie Wolf, Mike Randich and Lisa Spalla
Project Address: Farmington, CT
Bdrms./Sq. Footage: TBD
General Project Overview:
Mike Randich and Lisa Spalla's new home in Farmington is designed and built by Wolfworks, Inc. according to the International Passive House standard. Passive House design and construction assure the remarkably low energy demand that is ideally aligned with the goals of the Zero Energy Challenge: to first maximize energy efficiency and subsequently focus on on-site generation.
Passive House is a rigorous and uncompromising building energy design and performance standard developed and proven in Germany, being embraced internationally and now gaining ground and admiration in the US for its impressive performance. There is no dictate about style. To be certified as a Passive House the home must achieve three strict performance criteria:
- Heating Energy Demand less than 4.75 Kbtu/sf/yr
- Air leakage less than 0.6 ACH50
- Primary Energy Demand for all building energy needs less than 38 Kbtu/sf/yr
Passive House assures that a building takes the greatest advantage of available “gains” while minimizing energy “losses.” The resulting “energy balance” provides a building with exceptional comfort and health, simplified operation and dramatically lower operating costs.
Orientation and Envelope:
The house is a simple one story 30' x 46' rectangle with walk out living space below. It also has an 11' x 14' mudroom entry adjacent to a two car garage and a long south facing roof that spans the house and garage.south The orientation allows south facing windows to capture solar energy. Triple glazed Tilt-Turn windows from Schuco provide the capacity to assure that the net performance of all the windows is gaining more energy than they are losing on an annual basis. In a sense, the windows are providing some of the energy we have traditionally depended on mechanical systems to provide.
Insulation and Air Sealing:
- “Sandwich Wall:” a double stud 12" wall with dense pack cellulose in the 2x6 exterior and 2x4 interior frame walls, 24" on center exterior walls and polyiso foam panels in the 3" center
- Ceiling created by the truss roof is sheathed and taped with no penetrations to maintain a continuous air barrier
- Thermal bridge free detailing
- Rigorous attention to the sealing of all potential sources of air leakage using SIGA tapes
- Intermediate infiltration testing to remediate any leakage discovered during testing
Heating, Cooling, and Hot Water:
With an extremely low peak heat load of 12.5 Kbtu/hr this house could be served by approximately two hair dryers. A Fujitsu mini-split air source heat pump will provide both heating and cooling for the small load this home requires.
The domestic hot water is provided by a Stiebel Eltron heat pump water heater with a COP of 2.51
This extremely tight home will benefit from the control of constant fresh air provided by a highly efficient Zehnder heat recovery ventilation system. In standard construction, natural ventilation is uncontrolled and the source of considerable heat loss. This balanced system recovers most of the heat from the steady and balanced flow of air it is designed to regulate, allowing the home to constantly breathe.
House lighting will consist of LEDs and CFLs in nearly all fixtures. The most energy efficient appliances have been selected.
A photovoltaic array is being designed to provide all the energy necessary, on an annual basis, to power the home and all its functions.