FINALSSS Flashcards
Meaning of HVAC
Heating, Ventilating, and Air Conditioning
Backbone of modern building and environmental control.
HVAC
HVAC systems regulate what?
- Temperature
- Humidity
- Air quality
- Air movement within buildings
This marked a significant turning point in HVAC technology.
The Industrial Revolution
HVAC systems have evolved from simple heating methods in ______ to complex, integrated systems in modern buildings.
Ancient Rome
What is the purpose of HVAC systems?
Aim to provide thermal comfort and acceptable indoor air quality.
Modern HVAC systems integrate these into a single, efficient package.
Heating, cooling, and ventilation
What trends and advancements do HVAC systems incorporate?
Smart technologies, energy-efficient designs, and sustainable practices
Factors influencing HVAC design
- Building Characteristics
- Climate and Location
- Occupancy and Usage
A factor that influence HVAC design which deals with the size, layout, and purpose of a building.
Building Characteristics
A factor that influence HVAC design which deals with the local weather patterns, humidity levels, and seasonal temperature variations.
Climate and Location
A factor that influence HVAC design which deals with the number of occupants, their activities, and schedules.
Occupancy and Usage
Air Conditioning and Heating Principles
- Heat Transfer
- Refrigeration Cycle
- Heating Methods
- Energy Efficiency
HVAC systems rely on the principles of conduction, convection, and radiation to move heat energy.
Heat Transfer
Heat Transfer Principles
- Conduction
- Convection
- Radiation
Heat transfer through direct contact between particles of matter.
Conduction
Heat transfer by the movement of fluids or gases. This is the primary method of heat distribution in HVAC systems.
Convection
Heat transfer through electromagnetic waves.
Radiation
Air conditioning utilizes the vapor compression cycle.
Refrigeration Cycle
Cooling Systems: Refrigeration Cycle
- Compression
- Condensation
- Expansion
- Evaporation
The compressor increases the pressure and temperature of the refrigerant vapor. This high-pressure, high-temperature gas then flows to the condenser.
Compression
The hot refrigerant vapor releases heat to the surroundings and condenses into a high-pressure liquid. This process typically occurs outside the cooled space.
Condensation
The high-pressure liquid refrigerant passes through an expansion valve, which reduces its pressure and temperature, turning it into a low-pressure, lpw-temperature mixture of liquid and vapor.
Expansion
The cold refrigerant absorbs heat from the indoor air, cooling the space. The refrigerant fullt vaporizes and returns to the compressor to repeat the cycle.
Evaporation
Various heating technologies, such as combustion, electric resistance, and heat pumps, are employed to generate warmth.
Heating Methods
Modern HVAC systems focus on maximizing energy efficiency through improved thermodynamic cycles, heat recovery systems, and smart control algorithms.
Energy Efficiency
Components of HVAC Systems
- Fans and Blowers
- Chillers and Boilers
- Pumps and Exhaust Fans
- Controls and Sensors
AHU
Air Handling Unit
These are centralized units that condition and circulate air. They typically include fans, heating and cooling coils, filters, and dampers.
Air Handling Unit (AHU)
The heart of many commercial HVAC systems, managing airflow and temperature control.
Air Handling Unit (AHU)
FCU
Fan Coil Unit
It is a powerful unit helpful in circulating cool or warm air across single spaces. Often installed within or near the space it serves.
Fan Coil Unit (FCU)
It remove heat from water for cooling
Chillers
It heat water for heating.
Boilers
Responsible for moving air and water through the system.
Pumps and Exhaust Fans
The brain of HVAC systems, including thermostats, humidity sensors, and building automation systems.
Controls and Sensors
Air Distribution and Ductwork
- Duct Design
- Air Balancing
- Diffusers and Grilles
- Maintenance
Proper _____ ensures efficient air distribution. Factors include sizing, material selection, and layout optimization to minimize pressure drops and energy loss.
Duct Design
The process of adjusting airflow to ensure proper distribution throughout the building. This invloves measuring and adjusting dampers and diffusers to achieve desired airflow rates.
Air Balancing
These components distribute conditioned air into spaces and collect return air. Proper selection and placement are crucial for occupant comfort and system efficiency.
Diffusers and Grilles
Regular cleaning and inspection of ductwork prevent buildup of contaminants amd ensure optimal system performance.
Maintenance
Louvered perforated covering for a duct opening, which can be located on a wall, ceiling or floor.
Grille
Combination of a grille and a damper.
Register
Controls air flow of supply air to the conditioned space.
Damper
Circular, square, rectangular, or linear supply outlet, typically located in the ceiling and discharges supply air in various directions and planes
Diffuser
Ventilation and Indoor Air Quality
Mechanical Ventliation
Air Filtration
Humidity Control
CO2 Monitoring
Uses fans to circulate fresh air into buildings, removing stale air and pollutants.
Mechanical Ventilation
Removes particles and constraints from the air. HEPA filters and electronic air cleaners can significantly improve indoor air quality by capturing allergens, dust, and microorganisms
Air Filtration
Maintains optimal humidity levels to prevent mold growth and enhance comfort.
Humidity Control
Measures carbon dioxide levels as an indicator of air quality and occupancy.
CO2 Monitoring
HVAC System Design Considerations
Load Calculations
Energy Efficiency
Sustainability
HVAC Energy Efficiency Tips
- Add programmable thermostat
- Invest in thermal insulation
- Ensure smooth airflow
- Switch to VRF (Variable Refrigerant Flow) HVAC
- Turn off electronic appliances
- Ensure regular maintenance
