# Thermal Comfort PMV-PPD (ISO 7730 / Fanger) Compute the thermal comfort indices PMV (Predicted Mean Vote, −3 cold..+3 hot) and PPD (Predicted Percentage Dissatisfied, %) per ISO 7730 / ASHRAE 55, using the Fanger equations. Inputs: air temperature Ta, mean radiant temperature Tr, relative air velocity v_ar, relative humidity φ, metabolic rate M (met; 1 met = 58.2 W/m²), clothing insulation Icl (clo; 1 clo = 0.155 m²·K/W), and external work W (defaults to 0). The clothing surface temperature Tcl is solved iteratively. Returns a 7-level ASHRAE sensation label. > Canonical page: https://elysiatools.com/en/tools/thermal-comfort-pmv - **Category:** Math & Numbers - **Keywords:** PMV, PPD, thermal comfort, Fanger, ISO 7730, ASHRAE 55, predicted mean vote, predicted percentage dissatisfied, metabolic rate, clo, clothing, mean radiant temperature ## Overview Thermal Comfort PMV-PPD calculates Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD) using the Fanger equations from ISO 7730 and ASHRAE 55. Enter air temperature, mean radiant temperature, air velocity, humidity, metabolic rate, and clothing insulation to receive a thermal sensation label and supporting results. ## Inputs - **Air Temperature Ta** (number): Dry-bulb air temperature Ta, in the selected Temperature Unit. - **Mean Radiant Temperature Tr** (number): Mean radiant temperature Tr, in the selected Temperature Unit. - **Temperature Unit** (select) - **Relative Air Velocity v_ar** (number): Relative air velocity v_ar in m/s. Typical office 0.1 m/s. 0–3 m/s. - **Relative Humidity φ** (number): Relative humidity φ in % (0–100). - **Metabolic Rate M (met)** (number): Metabolic rate M in met (1 met = 58.2 W/m²). Seated/resting 1.0, office standing 1.2, light work 1.6–2.0. - **Clothing Insulation Icl (clo)** (number): Clothing insulation Icl in clo (1 clo = 0.155 m²·K/W). Summer light 0.5, winter business suit 1.0. - **External Work W (met)** (number): External mechanical work W in met. Usually 0 for office / sedentary activity. - **Decimal Places** (number) ## When to use - Estimate perceived thermal comfort in offices, classrooms, and other occupied spaces. - Compare comfort conditions for different temperatures, humidity levels, clothing, or activity rates. - Review PMV and PPD values during HVAC, building, or indoor-environment assessments. ## How it works - Enter air temperature Ta and mean radiant temperature Tr, choosing Celsius or Fahrenheit. - Provide relative air velocity, relative humidity, metabolic rate in met, and clothing insulation in clo. - Optionally enter external work; it defaults to 0 met for sedentary activities. - The tool solves clothing surface temperature iteratively and returns PMV, PPD, and a seven-level thermal sensation label. ## Use cases - Evaluate office comfort using indoor temperature, radiant temperature, humidity, activity, and clothing assumptions. - Compare summer and winter clothing scenarios with different clo and met values. - Communicate comfort results with PMV, PPD, and a clear sensation label. ## Frequently asked questions ### What do PMV and PPD mean? PMV estimates the average thermal sensation from −3 cold to +3 hot. PPD estimates the percentage of people predicted to be dissatisfied. ### What temperature inputs are required? Enter air temperature Ta and mean radiant temperature Tr. Both can be supplied in Celsius or Fahrenheit. ### What is the typical air velocity for an office? The default relative air velocity is 0.1 m/s, described as typical for an office. ### What do met and clo represent? Met represents metabolic activity, while clo represents clothing insulation. One met equals 58.2 W/m², and one clo equals 0.155 m²·K/W. ### What happens if external work is not entered? 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