Heat exchange and transmittance and the idea

The heat exchange and trans mittance

1. HEAT EXCHANGE
ANDTRANSMITTANCE
AYSWARYA
KHADEEJA SIRIN
FATHIMA THANHA PMS

2. Heat exchange in buildings involves the transfer of heat between the building's
interior and its external environment. It occurs through three main
mechanisms:
1.Conduction: Heat transfer through solid materials, like walls, floors, and
roofs. The rate of conduction depends on the material's thermal
conductivity, thickness, and temperature difference across the material.2.
2.Convection: Heat transfer through fluid movement, including air or water. In
buildings, this happens via natural convection (movement due to
temperature differences) or forced convection (using fans or pumps).
3.Radiation: Heat transfer through electromagnetic waves, primarily from the
sun. Buildings absorb and emit radiant heat, affecting indoor temperatures.
HEAT EXCHANGE

3. Building Materials: Insulation materials reduce conduction, while thermal
mass materials (like concrete) can store and release heat.
Building Design: Orientation, window placement, and shading can control
solar gains and natural ventilation.
Climate and Weather: Outdoor temperature, humidity, wind, and solar
radiation impact heat exchange.
Occupant Behavior: Use of heating, ventilation, and air conditioning (HVAC)
systems, and activities like cooking or using electrical appliances.
FACTORS INFLUENCING HEAT EXCHANGE

4. Insulation:Using materials with low thermal conductivity to reduce heat loss or gain.
Air Sealing: Preventing air leaks to control unwanted heat transfer through convection.
Windows and Doors: Using double or triple glazing, low-emissivity (low-e) coatings, and
proper sealing.
Thermal Mass: Incorporating materials that absorb, store, and release heat to stabilize
indoor temperatures.
Passive Design: Orienting the building and designing features to maximize natural
heating, cooling, and lighting.
Active Systems: Employing HVAC systems, smart thermostats, and other technologies to
manage indoor climate efficiently . Effective management of heat exchange in buildings
improves energy efficiency, comfort, and reduces utility costs.
STRATEGIES TO CONTROL HEAT EXCHANGE

5. THE STACK EFFECT
FACTORS AFFECTING THE
STACK EFFECT
•Building Height:
•Temperature Difference
•Building Envelope
•Openings and Leaks
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IMPLICATIONS OF THE STACK
EFFECT
•Energy Efficiency
•Indoor Air Quality
•HVAC Design
MITIGATING THE STACK
EFFECT-
•Sealing Leaks
•Air Barriers
•Balanced Ventilation
•Zoning
The stack effect also known as the chimney effect, refers to the movement of air
into and out of buildings driven by buoyancy forces that result from differences in
indoor and outdoor air density due to temperature and humidity differences.
This phenomenon is especially noticeable in taller buildings and can significantly
impact heating, ventilation, and air conditioning (HVAC) systems, as well as indoor
air quality and energy efficiency.

6. THE VENTURI EFFECT
Applications in Building Design Building Height:
1. Natural Ventilation:
•Wind-Induced Ventilation
•Atriums and Courtyards
2. Cooling Towers
•Passive Cooling
3. Ventilation Shafts
•Stack Ventilation
4. Double-Skin Facades
•Enhanced Airflow
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Benefits of Using the VenturiEffect in Buildings
•Energy Efficiency
•Improved Indoor Air Quality
•Thermal Comfort
Design Considerations-
•Orientation and Placement
•Building Shape and Height
•Climatic Conditions
•Balanced Ventilation
•Zoning
The Venturieffect can be leveraged in building design to enhance natural ventilation and improve
indoor air quality. By strategically designing spaces and airflow pathways, architects and engineers
can create pressure differentials that drive air movement through a building without relying heavily
on mechanical systems. Here are some ways the Venturieffect is applied in buildings:

7. THE VENTURI EFFECT
High thermal conductivity materials :
Metals
•Aluminium
•Steel
•Copper
Insulating materials
Foam insultion
•Polystyrene (EPS and XPS)
•Polyurethane (PUR) and
polyisocyanurate(PIR):
Fibrous insulation:
Fiberglass
Mineral wool
Natural insulation
•Cellulose
•Cork
•Sheep wool
Thermal mass materials
•Concreete
•Brick and masonry
•Phase change material(PCMs)
Reflective Materials
•Radiant Barriers
Composite Materials
•Structural Insulated Panels (SIPs)
•Insulated Concrete Forms (ICFs)
Considerations for Selecting Heat
Transfer Materials
•Thermal Conductivity
•Thermal Mass
•Moisture Resistance
•Sustainability
•Fire Resistance
•Cost and Availability
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In construction, selecting appropriate materials for heat transfer is crucial for optimizing energy
efficiency, thermal comfort, and overall building performance. Different materials have varying
thermal properties, including thermal conductivity, specific heat capacity, and thermal mass. Here
are some commonly used heat transfer materials in construction:

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13. THANK YOU
AYSWARYA(9), KHADEEJA SIRIN (25), FATHIMA THANHA
PMS (18)
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