Amburg Danford House at Raven Rocks, Ohio
Occupants: John and Wanda Rockwell, 54551 Crum Road, Beallsville, OH 43716 • 740-926-1701 • Jonda99@gmail.com
Beginning in 1976 we gutted the 1892-vintage structure, then framed a second 2x4 wall inside all exterior walls and filled the resulting 8 1/2”-space with fiberglass batts (R-30+ for the complete wall system). The second-floor ceiling has blown cellulose and fiberglass batts amounting to R-50+ insulation. Vapor barrier inside the walls throughout the house consists of 6-mil black polyethylene film taped and caulked fanatically.
All new, well-sealed windows, mostly replicating the locations and sizes of the originals, are double glazed, the larger of which having Window Quilt insulating shades. The number and size of windows does not satisfy the 1970’s “super insulation” standards, which called for minimal, small north windows and limited openings in the east and west walls.
The new basement has poured concrete walls, insulated with 2” of rigid foam outside of walls and under floor, waterproofed with Thoroseal plaster and kept dry by gravel and a footer (“French”) drain.
We heat the house using a Vermont Castings “Defiant” cast iron catalytic wood burner, rated at 75,000 Btu/hr. On a cloudy 32-degree F. day without a fire in the stove, ten people in the house will maintain a constant 70 degrees F. inside. Under the same conditions, but with sunshine, the people will raise the temperature two or three degrees.
Flat-plate collectors for heating water are mounted on a roof with a slope of 9.5/12 (38 degrees from horizontal), coming down within five feet of grade. There are four 2-foot by 8-foot collector units built by Solartech of Salem, OH (who no longer manufactures solar equipment) that have been in use since 1983. Propylene glycol antifreeze solution is circulated by a 1/25 hp pump through a heat exchanger in the bottom of an 80-gallon Ford stone-lined tank. A simple differential thermostat provides automatic operation year-round. Repairs over the years have consisted of replacement once each of the one-gallon expansion tank, the mixing (tempering) valve and the thermostat. We have replaced the antifreeze every ten years or so. Snow is easily removed from the collectors with a long-handled brush.
The solar-heated water is sent directly to the use points during the warm half of the year, with the electric element in the solar tank turned on rarely. During winter, the output of the solar system is routed through a conventional 40-gallon electric water heater for boosting the temperature to 125 degrees.
There is a large Clivus Multrum composter in the basement, fed by three chutes connected to toilets on each floor above and a counter-top garbage inlet in the kitchen.
Speaking of chutes, there are three going from the kitchen to recycling bins in the basement, and one between the upper floors for laundry.
2007 Addition - Sunspace
Adjacent to the house is a 380-sq. ft. sunspace whose floor-to-peak height inside is over 21 feet. Numerous doors and other openings allow connecting the solar heated space to the living space. Because of the vertical separation of the openings into the house, moving hot air passively is an option.
A 3/4-horsepower blower mounted at the highest (and hottest) point in the sunspace connected to a duct system installed in the house during the renovation forces hot air through registers into most rooms. Manually changing a diverter flap allows the blower to send the hot air to rock heat storage in the basement before it enters the house. An additional option is achieved by opening a door in the rock storage which allows the hot air to discharge directly into the basement space.
Because of a huge (350 sq. ft.) solar aperture in the sunspace roof, inclined 38 degrees from horizontal and single-glazed with Kalwall fiberglass, the heat-gathering potential is intense. In order to limit heat loss on winter nights and to provide shading in warm weather, plans call for insulating (and reflective) shutters to be installed in all bays of the sunspace. They will be operated mechanically and independently in four zones. The hope is that the shutters can be used also to modify the environment in the sunspace for use as a greenhouse and expanded living space.
Extensive use of concrete in the floor and walls of the sunspace and three 12-sq. ft. openings into the basement provide considerable passive heat storage. Awning windows chest-high in the south wall and north windows at the highest level, over 20 sq. ft. of opening in each case, provide ventilation in warm weather.
2007 Addition – Garage with Loft
The basement level two-car garage (640 sq. ft.) adjoins the sunspace such that a well-insulated, 330-sq. ft. guest room above the garage is accessed through the sunspace. The exterior walls and roof of the room are insulated with a combination of soy-based, closed-cell sprayed polyurethane foam and fiberglass. Because of the air-tight, vapor-retarding properties of ccSPF, the roof deck is not ventilated. The roof of the garage is covered with standing-seam stainless steel. While the guest room can be heated by the sunspace, a 9,000 Btu/hr ductless heat pump is available to heat or cool if necessary.
The garage itself has poured concrete walls, insulated with three inches of extruded foam insulation on the outside, and a floor slab on 2”-thick rigid foam.
2007 Addition – Woodworking Shop
Attached to the north (back) wall of the garage is a 460-sq. ft. shop, also at basement level, constructed of pre-cast concrete wall panels supplied by Superior Walls. The walls incorporate an inch of rigid foam insulation, and we added another two inches on the outside, covered with sheet drain before backfilling. The footings for the Superior Walls use their design, consisting of fine crushed limestone, compacted and drained by perforated 4” pipe – no concrete under the walls.
The flat roof consists of 8”-thick pre-cast concrete planks, locked into the walls with steel reinforcing and a concrete cap. The concrete roof, with sprayed elastomeric waterproofing applied, had four inches of rigid foam insulation and sheet drain installed before being covered with at least eight inches of earth. Ajuga ground cover offers additional insulation. There are two operating skylights providing ventilation, natural lighting and emergency egress.
We don’t need to provide in the garage and shop any conditioning, except dehumidification in the shop during warm, humid weather.
Photovoltaic Solar Array
Twenty-two solar panels were added to the south-facing garage roof. The total wattage of the grid-tied PV system is 5.6 kiloWatts. Because of the “net metering” (the electric company’s meter runs forward and backward) option provided in Ohio, the system was sized to generate, on a yearly basis, slightly less than our total electrical usage.
In the 1970’s the aim in taking an old house in considerable disrepair and bringing it up to high standards of energy efficiency and comfort was prompted by energy shortages and the growing awareness of wide-spread, if not global, pollution (remember sulfur dioxide?). We hadn’t heard of Peak Oil, but it wasn’t hard to understand the significance of finite-resource depletion (remember “Limits to Growth”?). Our interest in energy efficiency has only intensified over the years, and we continue to think of our home as not just our Shangri-La but, hopefully, a demonstration of forward-looking design and construction.
While the configuration of the current construction generally matches the original 1976 Malcolm Wells concept, materials and technology improvements have influenced the execution. We feel discomfort over our extensive use of concrete and other materials with high-embodied-energy content, and have tried to soften the impact by the use of Superior Walls and efficient wooden I-joists in the roof of the sunspace and garage. At every turn we are attempting to make the whole complex long-lasting and easy to maintain.
Written May, 2009 and revised July, 2016