Which variable describes the radiant heat environment around a person?

• A. Radiant temperature
• B. Humidity
• C. Dry bulb temperature
• D. Air speed

Answer: (A)

Radiant temperature describes the radiant heat environment around a person. Heat exchange by radiation comes from all surrounding surfaces, and the effect depends on their temperatures and how much of the person’s surroundings those surfaces cover (view factors). The mean radiant temperature is the single value that would yield the same net radiant heat transfer as the actual surrounding surfaces. Humidity, dry-bulb air temperature, and air speed relate to moisture, convection, and cooling from moving air, but they don’t capture the radiant heat exchange from surfaces the way radiant temperature does.