The following info covers Collar Dome Heating Info for domes off the Grid.
(arrows on left and right change pictures)
Collar 45′ & 30′ Linked Domes in Moab, Utah
at 7,500 feet elevation
The concrete dome kits were purchased in 1996. The Collars were Do It Yourself builders. Their off the grid system includes photovoltaics, masory heater fireplace, passive solar water tubes and propane heaters.
The third photo shows the living room including the masonry heater fireplace top/center and the passive solar water tubes in the window on the left. The water tubes are also visible from the outside in photograph one. That’s a water feature over on the far right.
Photo number two shows a typical winter – although recent conditions have led to greater extremes with far less or even more snow.
The following heating recap was written by Mr. Collar in July of 2012.
Inside, the masonry heater (also called a “Russian furnace”) consists of a large masonry firebox topped with a flue internally configured as a maze. Flue gasses exit the top of the lower firebox and travel up and down and back and forth through the flue maze imparting heat into the masonry before going up the stack. The large mass of the firebox/flue stores the heat and radiates it out into the room over a long period. During winter I usually have one fire per day. I fill the firebox very full and light it off between 6:00 and 8:00 in the evening. The fire is not dampered but burns hot and fast so there’s little creosote buildup. The fire dies out between 10:00 and midnight and I close off the air supply and flue dampers for maximum heat retention. In the morning the fireplace masonry is hot to the touch and it simply radiates its stored heat all day keeping the dome comfortably warm. The fireplace is centrally located to maximize heating, extending into the master bedroom. I added two small forced air fans at the top of the firebox to pull even more air over the face and thus increase heat discharge — although I rarely use them.
There are 11 solar water tubes each about a foot in diameter and 8 feet tall placed in a large south-facing window. Originally designed for aquaculture, they are water-filled with waterbed conditioner added for algae control. In the winter the sun warms the water during the daytime. Even with nighttime temperatures below zero, the tubes can reach 85 deg F on a sunny day — especially if there’s snow on the ground to increase the solar radiation effect. At night the tubes re-radiate heat back into the house and I lower the thermal curtain between the tubes and the large window to prevent heat loss back outside. (The thermal curtain is visible in photo 2). I worked with American Ingenuity’s designers to ensure the entryway overhang was sized to shade the tubes during the summer and to provide adequate foundation to handle the extra weight of the water.
The house generally stays comfortable for up to three days without supplemental heat. However, I also have two small propane direct vent wall heaters which are used only when I expect to be gone for more than two days. I’m working on automating the thermal curtain to be able to raise and lower it for daytime solar gain when I’m not at home.
The following was exerted from a July 1998 Home Power magazine: “To power the home they utilized “Photovoltaic array of 32 BP-75 panels supplying an APT3 power center which charges their 2110 Amp-hour Pacific Chloride batteries. This is enough to last them three to five days, depending on usage. Given their ridge top location, they included lighning protection in the APT. A Trace SW4024 sine wave inverter provides clean electrical power with no noticeable line noise. A backup generator is available if needed.” “There average summertime power consumption is between 150 and 200 kWh/month for 2,700 sq.ft. of living space. Wintertime consumption is somewhat higher. For comparison, there average pre-solar usage was near 600 kWh/month in their 2,000 sq.ft. suburban home!”