The facility has been used to find the impact of component substitution on overall SDHW performance. In cooperation with the University of Wisconsin, we compared experimental data with simulation results to determine if the expected system performance could be predicted accurately. This work supported the development and verification of simulation models for SDHW systems required by manufacturers for certification under the SRCC's OG-300 rating system. These same models have supported manufacturers in becoming certified under the Sacramento Municipal Utility District's SDHW rebate program.
Experiments have identified key modeling parameters for open-loop solar domestic hot water systems with drain-back tanks and for closed-loop SDHW systems with external heat exchangers.
The advanced heat exchanger experiment will examine the performance of several unique systems which integrate the heat exchanger into the solar hot water storage tank. This includes wrap-around, mantle and side-arm thermosiphon systems.
Continued research is also addressing the modeling of SDHW systems using conventional external heat exchangers but operating at off-design conditions. This issue becomes especially important when modeling a system with variable collector flows from photovoltaic powered-pumps or performance optimized pumps.