Simple arithmetic
Tank runtime divides water volume by an output rate, adjusted by the entered active-time percentage. Energy is watts multiplied by operating hours, divided by 1000. Costs multiply quantities by the prices you enter. These calculations do not simulate the appliance.
Humidity approximations
Saturation vapor pressure uses 6.112 × exp(17.62 × T / (243.12 + T)) hPa. Absolute humidity is 216.7 × vapor pressure / (273.15 + T), in g/m³. Dew point inverts the same Magnus approximation. Temperature is in Celsius; tools restrict these approximations to 0–50 °C.
The air-water-gap tool considers only water vapor in the entered room volume. It excludes ventilation, materials and people. It cannot size a humidifier. The temperature/RH tool assumes constant vapor partial pressure and flags saturation.
Units and dates
One US gallon is 3.785411784 L; one imperial gallon is 4.54609 L. Calendar reminders are all-day events. Local logs can be exported to CSV and are not synchronized between devices.
Vaisala humidity calculator and conversion references
WMO Guide, Chapter 4, Annex 4.B: humidity formulae. These tools omit the small moist-air pressure enhancement correction.