The DD wizard has six Plant Equipment buttons available. By default, only the DHW equipment is enabled, since most buildings have domestic hot water plants. However, the remaining equipment categories remain “greyed out” or inactive until the user selects the corresponding system type.
Many new users of the program want to define additional equipment types but cannot activate more than one equipment category, even though they have modeled additional systems. This is because eQUEST only allows one type of plant equipment per shell. In order to have multiple plant types (i.e. CHW plant plus a GSHP plant), users must create additional shells.
Let’s take a look at an example:
Here, we have 1 shell, and two systems: a GSHP system and a chilled water systems.
However, only the GSHP plant equipment is activated. This is because the GSHP system is defined first. If we had defined the CHW system first, the CHW equipment would be available, and the GSHP equipment inactive.
In order to have two plant types, an additional shell must be created.