5. PROOF-OF-CONCEPT EXPERIMENTS 5.1 REFERENCE SYSTEM SUMMARY The initial Phase 0 study resulted in the selection of three Reference Systems. These were designated System A (Hot Water System), System B (Hot Water and Space Heating), and System C (Hot Water, Space Heating and Cooling) and were used to establish capture potential for solar energy systems. While these Reference Systems were cost-effective for many building types and cities, it was apparent that new, innovative designs should also be evaluated to further improve their cost-effectiveness, particularly for the overall combined hot water, space heating and cooling systems. The results of these evaluations led to the selection of three solar augmented heat pump systems as a means of reducing both initial costs as well as operating costs. The three solar augmented heat pump systems were designated Reference Systems (D), (E), and (F). Their general characteristics are given in Table 5-1. All three systems were designed to provide the combined building functions of service for hot water, space heating, and space cooling. The thermal models and system diagrams for Reference Systems (D) and (E) are shown in Figures 5-1, 5-2, 5-3, and 5-4. Systems (D) and (E) utilize a combination of solar augmentation and a variable pressure ratio heat pump to achieve significantly higher coefficients of performance than that achievable with a conventional heat pump. System (D), which is essentially an all-air system (except for the hot water function), uses crushed rock for both the hot and cold energy storage. System (E) circulates water through the collector loop but permits the option of using water or air in the building distribution loop. Both systems utilize heat pumps which are capable of operating with either "reverse-refrigerant" or "reverse-air or water" loops. In order to accommodate one of the Phase 1 recommended POCE's, a System (F) was also defined. This system, shown in Figure 5-5, is essentially a state-of-the-art modification of System (E). It includes a rock-bed regenerator to provide cooling and regenerative heating of circulation air and a conventional heat pump rather than a variable pressure ratio unit which is to be developed concurrently in Phase 1. Figure 5-1. Figure 5-2. Schematic Diagram of Reference System (D) Thermal Model Reference System (D) Solar Heat Pump System (Air Transfer- 56-516 O 75 Pt. 1C - 41 |