By default, the DD wizard will have one HVAC system listed under “Air-Side System Types:”. To edit this system, simply click the button “Edit selected system.
Users must select a Cooling and heating source. These selections interactively determine other fieldsets For instance, the available system types change dynamically when changing the cooling or heating source. If a system type remains unavailable, consider the possibility of selecting a different source.
System type selection determines the systems per area and return air path defaults. The options of system per zone, floor, shell, or site are available. The defaults are generally good choices. (The number of systems correspond to the number of supply fans for rooftop systems, WSHP’s, and VAV reheat systems, among others)
Then, users must assign systems to thermal zones. Keep in mind that the zoning in this wizard is more of a general zoning than exact. It allows a user to generalize assignments by floor, or room type (core vs exterior). With more complicated zoning, users must return to the zone groups section of the building shell.
The first screen in system selection is definitely the most important, as it determines the contents of the remaining screens. Furthermore, it determines which plant options will be activated within the DD wizard.
The remaining system options are relatively straightforward:
Screen 2 - Users must define design, and seasonal setpoints Screen 3- Define typical efficiencies and equipment sizes (it is a good idea to specify a size when comparing multiple options. For instance, when comparing glass options on an existing building, as the term “Auto-size” will allow eQUEST to manipulate equipment sizes with improved envelopes, which of course, does not happen when simply renovating a building envelope) Screen 4 - Define fan static/power, safety factor and unloading where applicable. Screen 5 - Define typical building schedules Screen 6 - Define Economizer mode (if applicable) and baseboard heating options Screen 7 - Define water temperature reset options.
Once all options are entered as specified (or defaults assumed), return to the navigator, where the corresponding plant options are now available (if only one system is present). We will discuss multiple plant types later.
Multiple systems may be defined by simply clicking “Create New System” and repeating the previously discussed process. When modeling multiple systems, it is important to assign systems to zones as accurately as possible in screen 1 of the “Air-side system wizard”. Remember to properly select the number of systems per zone, floor, shell etc.