Heat and Human Comfort

HVAC

CNST 305 Environmental Systems 1Dr. Berryman

5b HVAC Introduction, Human Comfort

4.39 Building Codes and Standards (3 hr)

Heat Simple molecular motion

• •

Heat Exchange

Principles of Heat Transfer

Methods of Heat Transfer

hotwater

hotwater

cool aircool air

warm airwarm air

60°F60°F 61°F61°F

15°C15°C 16°C16°C

1 Btu1 Btu

1 kcal1 kcal[4.19 kJ][4.19 kJ]

1 lb1 lbwaterwater

1 kg1 kgwaterwater

Measuring Heat Quantity

Sensible versus Latent Heat

60°F60°F[15.6°C][15.6°C]

212°F212°F[100°C][100°C]

212°F212°F[100°C][100°C]

212°F212°F[100°C][100°C]

sensible heatsensible heat

latent heatlatent heat

Radiant Heat Infrared radiation

• • •

Examples of Heat Sources Computer Light fixtures Coffee pot Sun People

Heat Generated by People

Surrounding Air Conditions

What makes the body feel comfortable?

Factors Affecting Human Comfort

Next Time The Study of Air/Water Mixtures Reading Assignment

Chapter 2 (Toa)