Enhancement Request: @DavidGoldwasser

General summary of the feature:

Providing Supply and Demand node in the OpenStudio Application for WaterHeater:Mixed

Detailed Description:

The WaterHeater:Mixed object includes the supply and demand node features in the IDF and EnergyPlus text modes, but it lacks the capability to explicitly define these nodes within the OpenStudio Application. Introducing this feature to OpenStudio would significantly streamline the integration of detailed HVAC systems, particularly in complex setups like those involving thermal storage tanks for energy flexibility. This enhancement could help reduce errors, especially in cases with multiple zones or intricate heating strategies, aligning with the broader goal of improving energy management systems.

Possible Implementation:

IronBug, a plugin from LadyBug Tools, leverages OpenStudio features to streamline the implementation of detailed HVAC systems. Its methodology simplifies the design of HVAC systems, even in large-scale and complex case studies. Many of these studies, which include systems such as boilers or heat pumps, incorporate water buffer storage tanks to provide additional hot water for space heating or service hot water. However, for buildings with numerous zones, correctly identifying and assigning node names becomes a significant challenge when implementing water storage systems.

Similarly, components like fluid-to-fluid heat exchangers in the OpenStudio application require explicit definition of supply and demand nodes. This feature is effectively integrated into IronBug, enabling users to easily specify these nodes. For example, the image below demonstrates the configuration of a fluid-to-fluid heat exchanger in IronBug, with clearly defined supply and demand sides.

In contrast, the WaterHeater:Mixed object in OpenStudio lacks this capability, making it exceedingly difficult to define supply and demand nodes within both IronBug and OpenStudio. The only workaround involves manually hardcoding the IDF script—a process prone to errors, especially when assigning nodes recursively.

Adding this feature to the WaterHeater:Mixed object would greatly enhance the ease and accuracy of defining detailed HVAC systems.

Thank you for your time and assistance. I look forward to hearing from you soon.

Sincerely,
Behnam Mohseni Gharyehsafa
National University of Ireland Maynooth