Heat Load is often where a job starts, before any system exists. Rooms built then are saved unassigned, and their loads can start a system or join one later.
Hand the loads to Cycle
- 1
Check the totals at the foot of the Room ledger: one per suction group, then All rooms.
- 2
Choose Use in Cycle. It opens the selected system in Cycle, or a new design when no system is selected.
- 3
Check the loads Kelvin filled in. A message says what it filled: one cooling load from all the rooms, or the medium- and low-temperature suction group loads.
- 4
Save the design in Cycle to keep them. Nothing is saved until you do.
The selected room's unsaved figures are included in what is handed over. With a single room in the ledger, its preset can also set a first-pass Evaporator temp.
Note
On a two-stage or transcritical CO₂ design, check each suction group's Load on Cycle against the ledger's group totals before you save. Choosing a preset on Cycle afterwards replaces the load it fills.
Suction groups
A room's Suction group routes its load to that group's total, and so to that compressor group in Cycle. A single-stage or cascade cycle has one main group. A two-stage or transcritical CO₂ cycle has a medium-temperature and a low-temperature group. A room saved against a group the system's cycle doesn't offer keeps it, and the ledger says it is not a suction group on this system's cycle.
Rooms saved unassigned
With no system chosen in System, rooms are saved unassigned, and feed the main suction group of a single-stage cycle. To bring them onto a system:
- 1
Save the design in Cycle, then come back to Heat Load and choose it in System. Choosing a system there changes it for every calculation page and the header.
- 2
A notice beside the ledger counts the unassigned rooms. Choose Move into, followed by the design's name.
- 3
The rooms join the end of this system's ledger, and their loads join its totals.
An unassigned room has no project location, so its design ambient and ambient RH are entered by hand. Once it is on a system with a location, its sheet says whether its ambient is the site's. See Set the project's location and design ambient.