Building Design and Indoor Environment Quality

Objectives of a Building

• Buildings provide shelter, facilitate human activities, and enhance thermal comfort.
• These objectives are influenced by the interaction between occupants, building design, and climate.

Importance of Indoor Environmental Quality

• Building design should prioritize indoor environmental quality.
• This includes factors like thermal comfort, ventilation, material selection, noise control, odor management, energy efficiency, and lighting.

The Human Body and Thermal Regulation

• The human body has a temperature regulatory system that maintains a core temperature of 37°C.
• Key sensors include the hypothalamus (heat sensor) and skin (cold sensor).
• These sensors trigger responses to maintain thermal balance.
• It takes time for the body to adjust its core temperature.

Metabolism and Heat Production

• The human body generates heat through metabolism, converting food into energy.
• The metabolic rate, and therefore heat production, varies based on activity level.
• One MET (metabolic equivalent) represents the energy produced by a sedentary person (18.4 Btu/h/ft2 or 58.2 W/m2).
• An average adult produces approximately 360 Btu/h (106 W) of heat.

Thermal Comfort and Heat Balance

• Maintaining thermal comfort requires balancing the body's heat production with heat loss.
• This involves achieving a specific combination of skin and core temperature.

Heat Transfer

• Heat is a form of energy that flows from a higher temperature to a lower temperature.
• The British thermal unit (Btu) measures heat energy.
• Heat transfer is the process of energy transfer through a medium due to temperature difference.
• There are three main modes of heat transfer: conduction, convection, and radiation, and one thermal process that involves heat loss only: evaporation.

Conduction

• Conduction involves direct heat transfer between molecules within or between materials.
• This occurs when there is a temperature difference between the two sides of a material.