Getting Started with ExCoil
From the first project to a checked selection: workflow, calculation modes, how to read the results, what each plan includes and how to report a problem.
1. Your first calculation in 6 steps
- Open the Dashboard and click “New Project”.
- Choose the exchanger type (DX evaporator, DX condenser, chilled water, hot water, steam, dry cooler or shell & tube), give it a name and create it. The calculator opens inside the project.
- Fill in the left panel: air or process conditions, the fluid side, then the coil geometry (tube, fins, rows, tubes per row, finned length, circuits).
- Choose the calculation mode (section 3) and press Calculate (
Ctrl+Enter). - Read the status and warnings before the capacity (section 4). Adjust geometry or circuits and recalculate until there are no blocking warnings.
- Save a version (
Ctrl+S) and export the PDF report (Ctrl+P) — Professional plan or higher.
Editing any input after a calculation invalidates the displayed result. Recalculate before saving or exporting, so the report always matches the inputs.
2. Which module to use
| Application | Module | Modes |
|---|---|---|
| Direct-expansion cooling coil | DX Evaporator | TXV · Rating · Sizing |
| Air-cooled refrigerant condenser | DX Condenser | Rating · Sizing |
| Chilled water / glycol cooling coil | Chilled Water | Rating |
| Hot water / glycol heating coil | Hot Water | Rating |
| Steam heating coil (saturated steam) | Steam | Rating · Sizing |
| Fluid cooler (water, EG, PG) | Dry Cooler | Rating |
| Flooded/DX evaporators, condensers, liquid–liquid | Shell & Tube (separate add-on) | Rating + optional sizing |
3. Calculation modes (design vs. verification)
- Rating: you give the geometry and the flows; ExCoil calculates capacity, outlet states and pressure drops. Use it to verify an existing or proposed coil.
- Sizing: you give a target capacity (heat rejection for condensers). The refrigerant or steam flow is derived from that target, and the result tells you whether the geometry you entered reaches it and by how much it falls short. Steam sizing searches the number of rows. In the DX modules Sizing does not change the geometry for you: if the target is not met, increase face area, rows, fin density or circuits and recalculate.
- TXV (DX evaporator): ExCoil finds the refrigerant flow that produces the requested superheat, as an expansion valve would. Flows that the circuits cannot pass hydraulically are reported as not feasible.
There is no button called “Design Calc”: a design (selection) calculation is the Sizing mode, followed by Rating to confirm the final geometry.
4. Reading the results
- Status first: energy balance, target met / shortfall, outlet phase or superheat achieved, hydraulic feasibility.
- Warnings explain why a selection is not acceptable as entered (for example face velocity, refrigerant pressure drop or saturation-temperature drop, fluid velocity in the tubes). Treat them as design actions, not as cosmetic messages.
- Then capacity, sensible heat ratio, outlet conditions and pressure drops on air and fluid sides.
ExCoil results are preliminary engineering calculations. They are not a certification to ASME, TEMA, AHRI or any other code or standard; validate critical selections with test data or an independent method before manufacturing.
5. Result tabs and plans
| Tab / output | Available from |
|---|---|
| Results | Free |
| Save projects and versions, PDF / CSV / JSON export, Charts, 2D drawing and DXF | Professional |
| 3D view, STL and STEP, Circuitry designer, Headers, BOM & Cost, REST API | Enterprise |
| AI-assisted analysis (Intelligence) | Manufacturer |
| Shell & Tube | Separate monthly add-on — not included in any plan, including Manufacturer |
Circuitry, headers, 2D, 3D, STEP, BOM and the PDF are generated from the same geometry: change the circuits or header settings and every output updates together.
6. Free plan limits
- Up to 5 exchangers with 10 calculations each. Each project counts as one exchanger and has its own 10 calculations.
- Up to 3 projects in the project manager. Calculations made outside a project share a single exchanger slot.
- Saving versions and exports require Professional or higher. Paid plans have no calculation limits.
7. Units
Calculations run internally in SI. Choose the default unit pack (SI engineering, US HVAC or Refrigeration) in Settings → Company; inputs, results and reports follow it.
8. Keyboard shortcuts
Ctrl+EnterCalculateCtrl+SSave versionCtrl+PExport PDF ·Ctrl+EExport JSONCtrl+OOpen an .excl fileCtrl+Z/Ctrl+YUndo / redo input changesCtrl+/Show all shortcuts
On macOS use Cmd instead of Ctrl.
9. Reporting a problem
Open a ticket on the Support page and include:
- Module and calculation mode (for example: DX Condenser, Sizing).
- Project name, or the exported .excl/JSON file.
- What you expected (reference value and its source) and what ExCoil returned.
- A screenshot of the inputs, the status line and any warning or error message.