|
|
Passive House in the Woods
The Passive House in the Woods is a 1,900 square foot two-story single family home with walk-out basement level, and a rooftop terrace. It was commissioned by a private client, designed by TE Studio, and constructed by Morr Construction. It sits on just over one acre in the Town of Hudson, WI - minutes from Interstate 94. Located on the outer edge of a residential development, the home overlooks the St. Croix River Valley. The building lot provides stunning views and prime passive solar exposure. The property's north boundary is heavily wooded and borders undeveloped land. The design of the house works with the natural landscape, and minimizes impact on the wooded character of the lot. This house will be certified by the US Passive House Institute and MN GreenStar. System Components     Solar Electric and Solar Hot Water A 4.5 kW photovoltaic system, which includes a .84 kW roof mounted array and a 3.68 kW pole mounted, dual axis tracking array, generates a surplus (offsetting 2.78 tons of CO2 annually) over the energy consumed on site for a household of two people. The domestic hot water system utilizes a 40 square foot hot water solar collector on the roof to pre-warm water in a 50 gallon storage tank. It is capable of providing over 85% of the hot water used in the home. Backup heating is provided by a small electric on-demand water heater. Passive Solar The exterior walls, windows, doors, slab, and roof are designed according to Passive House principles and radically reduce the amount of energy used to condition the home. The exterior wall assembly consists of 11” Insulated Concrete Forms (ICF) for structure, and an 11” Exterior Insulation and Finish System (EIFS) facade with an overall R-value of 70. The windows and doors, which are Passive House certified, come with triple pane low-E coated glazing and insulated frames for installed R-values of 8, and solar heat gains of over 60%. The slab sits on 12” of extruded polystyrene insulation with an R-value of 60. The flat roof utilizes an average of 14” of polyisocyanurate insulation with an R-value of 95. Ground-Source Heat The heat-recovery ventilation system consists of a high efficiency heat-recovery ventilator, which is combined with a 600 foot PEX-tubing loop field—buried on the property—to pre-heat and pre-cool the incoming air stream. This also dehumidifies moist summer air. Electric in-floor heating mats with local room-air thermostats are used to provide about 10.5kBtu of additional heat during extreme cold winter temperatures. That compares to the energy draw of two hair-dryers. System Designer: Energy Concepts (Craig Tarr) System Installer: Energy Concepts Date of Installation Completion: June 30th, 2010 Anticipated Energy Delivery When Purchased
.84 kW roof mounted array produces 1,000 kWh/yr
3.68 kW pole mounted, dual axis tracking array produces 5,745 kWh/yr 40 square foot hot water solar collector produces 58 Therms/yr Percentage of Total Energy Needs Delivered: The 4.5 kW photovoltaic system provides 100% of the electricity used on site annually. The 40 square foot hot water solar collector provides over 85% of the hot water used in the home. |
||||||
