Solar heating for an observatory--Lincoln, Nebraska

Report describes solar-energy system for 50 seat observatory that provides 60 percent of space heating needs. System includes 9 flat-plate collectors, rock storage bin, blowers, controls, ducting, and auxiliary natural-gas furnace; it has five operation modes. Net energy savings were 11.31 million Btu for 12 months, or equivalent of 1.9 barrels of oil. Report appendixes list performance factor definitions, performance equations, and average area weather conditions.