Final answer:
In the domestic hot water screen, all heating systems including backups should be modeled to ensure a complete view of the home's energy use. It's important to recognize both input and output heat transfers to optimize the efficiency of the hot water system, which may include renewable technologies like solar panels.
Step-by-step explanation:
When modeling systems in the domestic hot water screen, one should include all heating systems, including backup. This approach ensures a comprehensive understanding of the domestic hot water system, which is significant as heating and cooling contribute greatly to energy use in homes. Current practices in developing environmentally friendly homes, including the use of solar heating, aim to reduce conventional energy consumption by optimizing heat transfers through various means such as radiation gain from windows and convection flows.
Dedicated systems such as those using renewable energy like solar panels and other technology such as on-demand electric hot water heaters, which supply heat to water only when needed, are viable options for efficient domestic hot water systems. The characteristics of the systems to be modeled include allowing for identification of heat transfers into and out of the system, which are pivotal in understanding how these systems function and contribute to a zero-energy house goal.