熱快適PMVとppdmodels

Overview

Thermal comfort is defined as the condition of mind that expresses satisfaction with the thermal environment (ASHRAE 55). The most widely used model is the PMV-PPD model by Fanger (ISO 7730).

PMV Scale

PMV	Sensation
+3	Hot
+2	Warm
+1	Slightly warm
0	Neutral
−1	Slightly cool
−2	Cool
−3	Cold

The target for comfort: $-0.5 < PMV < +0.5$

PPD — Predicted Percentage Dissatisfied

$PPD = 100 - 95 \cdot \exp\left(-0.03353 \cdot PMV^4 - 0.2179 \cdot PMV^2\right)$

Factors Affecting PMV

Factor	Variable	Typical Office Value
Air temperature	$T_a$	22–24 °C
Mean radiant temp.	$T_r$	≈ $T_a$
Air velocity	$v_a$	< 0.2 m/s
Relative humidity	$RH$	40–60%
Metabolic rate	$M$	1.2 met (seated office)
Clothing insulation	$I_{cl}$	0.5–1.0 clo

Note: Even at PMV = 0, at least 5% of occupants will be dissatisfied — this is the minimum possible PPD.