7 guides published so far — more are added regularly.
The exact Tetens saturation vapor pressure formula this calculator uses, where it comes from, a worked numerical check against steam-table values, and its accuracy limits.
How this calculator solves for wet-bulb temperature using the psychrometer equation and bisection search, plus how a real sling psychrometer measurement works in the field.
Dew point and wet-bulb temperature both drop below dry-bulb as air gets drier, but by different amounts for different reasons. Worked comparison table at four humidity levels.
What humidity ratio actually measures, the exact formula this calculator uses, a worked conversion between kg/kg, g/kg and grains per pound, and why HVAC load calcs use it instead of RH.
What enthalpy of moist air measures, the exact formula this calculator uses, a worked example, and how differential-enthalpy economizer control uses it to decide when free cooling pays off.
The specific volume formula this calculator uses, a worked example showing moist air is less dense than dry air at the same temperature and pressure, and why that matters for fan and duct sizing.
How to read the saturation curve, RH lines and process directions on a psychrometric chart: sensible heating/cooling, dehumidification, humidification, evaporative cooling and mixing.