Tip
Enter setpoint and differential, then calculate.
You can also log runs and export them anytime.
Calculator
Example data table
Sample greenhouse configurations showing typical setpoints and switch points.
| Scenario | Mode | Units | Setpoint | Diff | Interpretation | Cut-in (ON) | Cut-out (OFF) |
|---|---|---|---|---|---|---|---|
| Seedling bench, cool night | Heating | °C | 22.0 | 2.0 | One-sided | 20.0 | 22.0 |
| Tomato tunnel, sunny day | Cooling | °C | 28.0 | 3.0 | One-sided | 28.0 | 25.0 |
| Propagation mat, gentle swing | Heating | °F | 75 | 4 | Total band | 73 | 77 |
Formula used
This calculator outputs two thresholds: cut-in (device turns ON) and cut-out (device turns OFF). The gap between them is the differential (hysteresis).
| Mode | Interpretation | Cut-in (ON) | Cut-out (OFF) |
|---|---|---|---|
| Heating | One-sided | Ton = S - D | Toff = S |
| Cooling | One-sided | Ton = S | Toff = S - D |
| Heating | Total band | Ton = S - D/2 | Toff = S + D/2 |
| Cooling | Total band | Ton = S + D/2 | Toff = S - D/2 |
Where S is the effective setpoint (setpoint + offset) and D is the differential in the chosen units.
How to use this calculator
- Pick your units and control mode for the device.
- Enter a setpoint that matches your plant target.
- Enter a differential to limit short cycling.
- Select how your controller defines the differential.
- Optionally add a sensor offset and notes, then calculate.
- Use CSV/PDF exports to track seasonal adjustments.
Saved runs
Logged results are stored in your current browser session.
No saved runs yet. Enable "Log this run" and calculate to populate the table.