Environmental Principles Week 2 Slideshow

Thermal Comfort

A subjective state of satisfaction with the thermal environment.

ASHRAE Definition of Thermal Comfort (1989)

Condition of mind in which satisfaction is expressed with the thermal environment.

Factors Affecting Heat Loss

Four main factors: Air Temperature, Mean Radiant Temperature, Relative Humidity, and Air Speed.

Air Temperature

How warm or cold the surrounding air is.

Mean Radiant Temperature

Temperature of surrounding surfaces impacting heat exchange.

Relative Humidity

Moisture in the air affecting heat dissipation.

Air Speed

Movement of air aiding heat loss through convection and evaporation.

Convection

Heat lost to moving air.

Radiation

Heat transfer to surrounding surfaces.

Evaporation

Heat loss through perspiration.

Conduction

Direct heat transfer to objects in contact.

Thermal Equilibrium

Balance between metabolic heat production and heat dissipation.

Clo Value

Measures insulation provided by clothing, with 0 Clo being nude and 4 Clo being maximum practical insulation.

Met Rate

Higher activity levels lead to more metabolic heat and greater need for cooling.

Indoor Environmental Quality (IEQ)

Affects health, productivity, and well-being.

Predicted Mean Vote (PMV)

Thermal sensation rating on a -3 to +3 scale.

Predicted Percentage of Dissatisfied (PPD)

Percentage of people dissatisfied with thermal conditions.

Thermal Resistance (R-Value)

Resistance of materials to heat flow.

Heat Flow Coefficient (U-Value)

Measure of heat conductance, inverse of R-value.

Building as a 'Third Skin'

Concept that buildings provide thermal regulation alongside clothing and body mechanisms.

Adaptive Comfort Models

Models considering individual differences like age, gender, and psychology.

Smart Buildings & AI

Integrating sensors for personalized comfort models.