February/March 1983 RAIN Page 23 hanging in it to prevent corrosion. The anodes are more easily corroded than the tank metal; therefore, they are 4;, sacrificed. I A unique feature of the system is the vertical two-story I storage tank installed in a well-insulated 10" x 10" x 20" high room. All of the controls and connections are easily accessible. The tank room is used for drying fruits and I vegetables. ,* “Some people laugh about solar around here,” says f Marie Kuehl, “but even when the sun isn't fully out, the system runs. We've been running on solar until just this week (mid-December) when it decided to rain a whole winter's worth in a few days." After the first full year of solar system operation, the total electricity use is under 8000 kWh, 57 percent of what was required without solar. Robert Brevik's home sits on a south-facing hillside, overlooking Klamath Falls, a town of 17,000 in south central Oregon. The climate is cold in the winter, hot in the summer, and dry year round. Brevik received a grant to demonstrate the effectiveness of an energy-efficient modification of his house. The house had been exposed to winter wind, and unprotected south windows had caused summer overheating and excessive winter heat loss. Brevik added a partially underground room which deflects winter winds and reduces heat loss on the west and north sides. He added a greenhouse to the existing deck in front of the windows on the south side. The greenhouse, using thermal storage mass to collect the heat, moderates the temperature of the rest of the house. Excessive summer heat can be released through the greenhouse vents, while in winter the thermal storage units radiate heat slowly. Flat plate solar collectors traditionally circulate liquid either with pumps or by thermosiphoning. A thermosiphon system requires no outside power source. It uses the density difference between the hot liquid in the collector and the cooler denser liquid in the storage tank to induce a convection current in a closed loop. A thermosiphon design requires that the storage tank be located above the collector. A mechanically pumped system uses electricity to circulate the liquid from the collectors to a storage tank. ' Eldon Haines of Bohemia Solar and Scientific in Eugene has developed a third type of flat plate collector system. His gevser-pump collector uses a small fraction of the absorbed heat to drive an internal integral pump with no moving parts to circulate the hot liquid. Designed to be self-regulating, the geyser-pump system uses no electrical energy and requires no sensors, motors, controllers, or valves. Unlike thermosiphon systems, the storage tank can be placed below the collector. Haines sees significant advantages in the geyser-pump system. He believes the new design will be easier to install than complex pumped systems. It will be simple to operate and maintain and will be energy self-sufficient, functioning even during an electrical power outage. Haines has used his grant to solve design problems and to determine operating parameters and efficiencies. He is now testing and further improving his working prototype. His goal is to manufacture and distribute the geyser-pump collector. “There were some pleasant surprises in the analysis of Eldon Haines displaying his revolutionary geyser-pump collector. the project," Haines said. "In doing the cost analysis, in life costing, the drairt down cycle systems were projected to be 30 percent above the geyser-pump system, and the drainback systems were 100 percent higher. Another surprise was that it doesn't seem to matter how high the collector is above the storage tank." In Eugene, Mark Palmer received a grant to study the retrofit options available to existing housing in the Northwest, particularly weatherization, attached solar greenhouses, and window insulating systems. The Westside Retrofit Project began with a standard heat loss analysis and visual infra-red analysis of an uninsulated two and one-half story house built during the late 1920s. The walls, floors, and attic were then insulated, weatherstripping added, and plastic storm windows installed. An attached solar greenhouse with 155 square feet of glazing was added to the south wall. At the same time, the building was remodeled into a duplex. The grant project evaluated the dynamics of thermal storage mass-to-glazing ratios in the greenhouse. Since the glazing area was fixed, the thermal storage mass was varied. With no mass the interior temperature of the greenhouse often exceeded 100° F on sunny winter days. The thermal mass was added in 25 percent increments of its final volume. Each of the first three additions decreased the temperature extremes by 6° F, and the final 25 percent increment decreased the extremes by 4° F. A significant effect of increasing the mass storage was
RkJQdWJsaXNoZXIy NTc4NTAz