Psychrometric Chart Calculator Excel

Wait – careful: ( W = 0.62198 * p_w / (P - p_w) ). So correct formula:

Once you have the vapor pressure ($P_w$) and atmospheric pressure ($P$), you can calculate the Humidity Ratio. The formula is:

Psat=0.61121×exp(17.67×TT+243.5)cap P sub s a t end-sub equals 0.61121 cross exp open paren the fraction with numerator 17.67 cross cap T and denominator cap T plus 243.5 end-fraction close paren (Where is Dry Bulb Temperature in 2. Humidity Ratio ( psychrometric chart calculator excel

Once the basic calculator works, supercharge it with these Excel features:

You can now perform sensitivity analyses (e.g., "What if outdoor RH rises from 50% to 80%?"), integrate with energy models, and produce client reports with consistent, error-proof calculations. Wait – careful: ( W = 0

Create a clean dashboard area in rows 1-10:

Cell B10.

h = (0.240 * T) + (W * (1061 + 0.444 * T)) – (Btu/lb, English units)

Excel does not have built‑in psychrometric functions. Instead, we must implement empirical correlations from ASHRAE Handbook—Fundamentals. The most important is the (Hyland‑Wexler formulation, valid 0–200°C): Humidity Ratio ( Once the basic calculator works,

Psychrometrics—the study of the thermodynamic properties of moist air—is fundamental to HVAC design, building science, agricultural storage, and industrial drying processes. The standard tool for visualizing these relationships is the psychrometric chart, a complex graph with dry-bulb temperature on the x‑axis and humidity ratio on the y‑axis, overlaid with curves for relative humidity, wet‑bulb temperature, specific volume, and enthalpy.