A refrigeration project's design ambient comes from where the project is. You choose the location once, on Cycle, and the stations after it read it from there.
- 1
On Cycle, under Project location, type the town, country or WMO number in Where is the project?
- 2
Pick the station from Weather station. Its outdoor design data is copied into the project with its source, and Design ambient is set to its annual cooling design dry bulb.
- 3
If the station publishes more than one, choose the Annual percentile. Each option shows its dry bulb, and pointing at one shows about how many hours a year it is exceeded.
- 4
Save the design. The location is kept with it.
To change it, type in Change location and pick another station. A new station keeps the percentile you chose when it publishes that one.
What follows from it
- On a transcritical CO₂ booster, the gas cooler exit is the design ambient plus the Approach TD, so the location sets the high side. On the other cycle types you enter the condensing temperature, and the design ambient is kept with the design.
- The Cycle report prints the location, and where the ambient came from with its citation.
- In Heat Load, a new room on a system with a location starts at the site's dry bulb, with its ambient RH worked from the station's mean coincident wet bulb at the site's elevation. If the station gives no coincident wet bulb, the RH is entered by hand.
- A saved room is never changed. A room whose ambient isn't the site's says so: Use the site's ambient sets the site's figures, and Save room keeps them.
- The Energy station can take its monthly climate from the same location.
Editing the design ambient
Design ambient stays editable on every cycle type, because you may have a reason for another figure. A figure that isn't the site's is never passed off as it. A note beside the field reads “Ambient differs from the site” and gives both figures, or “Project location not entered” when no location is chosen, so the figure has no source. Heat Load's rooms carry the same notes.
When a station can't be found
- Type at least two characters to search. The list shows the first 50 matches, so type more to narrow it.
- A station with no cooling design dry bulb in the library can't be picked, and Kelvin says so.
- If the weather-station library can't be loaded, or holds no stations, you can still type the design ambient, but it has no source and the note says so.
Note
The station's data is copied into the project, not linked, so a later change to Kelvin's library never changes a project's ambient.