Audi Audi A4 2005-2008 HVAC Specifications
Comprehensive technical specifications for the HVAC system in the 2005-2008 Audi A4. Learn about system components, refrigerant types, airflow management, and diagnostic procedures specific to the B7 platform.
Audi A4 (2005-2008) HVAC Specifications Overview Specifications
This document provides a comprehensive overview of the HVAC (Heating, Ventilation, and Air Conditioning) system specifications for the 2005-2008 Audi A4. It includes detailed information about system components, operational parameters, and maintenance guidelines. Use this guide to understand the functionality, performance, and service requirements of the HVAC system. Refer to the sections below for specific details and use the quick reference section for key specifications.
How to Use
To find specific information, use the search functionality by entering relevant keywords such as 'compressor', 'heater core', or 'refrigerant'. The search will highlight matching sections and subsections.
Navigate through the document by selecting sections from the table of contents. Each section contains subsections with detailed technical points. Use the quick reference section for fast access to key specifications.
Key Specifications
Compressor Type
Variable displacement
Refrigerant Type
R-134a
Condenser Size
520mm x 400mm
Evaporator Size
320mm x 200mm
Cabin Air Filter Type
Activated carbon
Available Specifications
System Overview
This section provides a general overview of the HVAC system, including its components, features, and operational characteristics. It serves as a foundational guide for understanding the system's layout and functionality.
System Overview
This section provides a general overview of the HVAC system, including its components, features, and operational characteristics. It serves as a foundational guide for understanding the system's layout and functionality.
System Components
- Heater core integrated into the dashboard
- Evaporator located behind the dashboard
- Condenser mounted in front of the radiator
- Compressor driven by the serpentine belt
- Expansion valve regulating refrigerant flow
- Dual-zone climate control available on higher trims
System Features
- Automatic climate control with temperature settings
- Air quality sensor for recirculation mode
- Rear seat heating vents (optional)
- Cabin air filter with pollen and dust trapping
- Defrost function for rapid windshield clearing
- Fresh air and recirculation modes
Heating System
This section details the heating components and their functionality, including the heater core, controls, and heat exchanger. It provides technical specifications and operational guidelines.
Heating System
This section details the heating components and their functionality, including the heater core, controls, and heat exchanger. It provides technical specifications and operational guidelines.
Heater Core
- Location: Integrated into the dashboard
- Function: Transfers heat from engine coolant to cabin air
- Material: Aluminum core with plastic end tanks
- Coolant flow controlled by the heater control valve
- Maximum operating temperature: 105°C (221°F)
- Recommended coolant type: G12 or G13
Heating Controls
- Electronic control module manages heating and cooling
- Temperature settings adjusted via dashboard controls
- Heater fan speed: 4 selectable speeds
- Heater control valve: Electrically actuated
- Cabin temperature range: 15°C to 28°C (59°F to 82°F)
- Defrost mode prioritizes windshield heating
Cooling System
This section covers the components and operation of the air conditioning and cooling system, including the compressor, condenser, and evaporator.
Cooling System
This section covers the components and operation of the air conditioning and cooling system, including the compressor, condenser, and evaporator.
Compressor
- Type: Variable displacement compressor
- Driven by the serpentine belt
- Pressure relief valve integrated
- Oil type: PAG oil (compliant with R-134a)
- Maximum operating pressure: 25 bar (363 psi)
- Noise level: <40 dB at idle
Condenser
- Type: Tube-and-fin design
- Location: In front of the radiator
- Coolant flow direction: Top-to-bottom
- Fan operation: Dual-speed electric fans
- Size: 520mm x 400mm (20.5" x 15.7")
- Material: Aluminum with epoxy coating
Air Quality
This section provides information on the air filtration and recirculation features of the HVAC system, including the cabin air filter and air quality sensor.
Air Quality
This section provides information on the air filtration and recirculation features of the HVAC system, including the cabin air filter and air quality sensor.
Cabin Air Filter
- Location: Behind the glovebox
- Type: Activated carbon filter
- Filter efficiency: 99.97% at 0.3 microns
- Replacement interval: Every 15,000 miles or as needed
- Function: Removes pollen, dust, and odors
- Recommended replacement part: Audi OEM or equivalent
Recirculation Mode
- Activated via dashboard button
- Closes fresh air intake flap
- Recirculates cabin air for faster cooling/heating
- Air quality sensor monitors pollutants
- Automatic mode available on higher trims
- Reduces outside noise and odors
Controls and Sensors
This section details the electronic controls and sensors that manage the HVAC system, including the climate control unit and temperature sensors.
Controls and Sensors
This section details the electronic controls and sensors that manage the HVAC system, including the climate control unit and temperature sensors.
Climate Control Unit
- Location: Behind the dashboard
- Function: Manages heating, cooling, and airflow
- Features: Dual-zone temperature control
- Inputs: Temperature dials, fan speed, and mode controls
- Outputs: Heater, AC, and blower motor signals
- Diagnostic capability via OBD-II
Temperature Sensors
- Cabin temperature sensor located in the center vent
- Ambient temperature sensor in the front bumper
- Evaporator temperature sensor integrated
- Sunlight sensor on the dashboard
- Heater core temperature sensor
- Condenser temperature sensor
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Component Specifications
Overview
- Type
- Automatic Climate Control
- Configuration
- Dual-Zone
- Refrigerant
- R-134a
- System Type
- Manual and Automatic Modes
- Control Location
- Dashboard-mounted controls
Dimensions
- Compressor Length
- 12.5 inches (318 mm)
- Condenser Width
- 26.5 inches (673 mm)
- Evaporator Height
- 6.3 inches (160 mm)
- Heater Core Length
- 14.2 inches (361 mm)
- Ducting Diameter
- 3.5 inches (89 mm)
- Blower Motor Width
- 7.9 inches (201 mm)
Materials
- Compressor
- Aluminum alloy
- Condenser Coils
- Copper with aluminum fins
- Evaporator
- Aluminum with plastic end caps
- Refrigerant Lines
- Steel with rubber insulation
- Heater Core
- Copper and aluminum
Features
- Air Quality
-
- Air quality sensor
- Automatic recirculation mode
- Pollutant-sensitive sensors
- Climate Control
-
- Dual-zone temperature control
- Automatic climate control
- Cabin temperature display
- Airflow
-
- Variable blower speed control
- Multi-directional air vents
- Rear cabin ventilation
- Filtration
-
- Cabin air filter
- Particle filter
- Odor-neutralizing filter
- Defrost
-
- Automatic defrost control
- Air recirculation during defrost
- Rapid defrost function
Safety Features
- Pressure Protection
-
- High-pressure cut-off switch
- Low-pressure safety valve
- Thermal Protection
-
- Heater core temperature sensor
- Automatic shut-off in case of overheating
- Leak Detection
-
- Refrigerant leakage detection
- System warning light
Comfort Features
- Temperature Control
-
- Dual-zone temperature adjustment
- Cabin air temperature sensor
- Floor and dashboard ventilation
- Airflow Management
-
- Variable blower control
- Airflow direction control
- Rear seat ventilation outlets
- Humidity Control
-
- Humidity sensor
- Automatic air recirculation
- Dehumidify mode
Accessories
- Optional Features
-
- Rear climate control
- Air quality package
- Remote climate control activation
- installation Kits
-
- Rear vent installation kit
- Additional air filter kit
- Climate control upgrade kit
- Maintenance Kits
-
- Cabin air filter replacement kit
- Refrigerant recharge kit
- Climate control system cleaner
Maintenance
- Service interval
- 15,000 miles (24,000 km) or 12 months
- Service Items
-
- Inspect and replace cabin air filter
- Check refrigerant levels
- Inspect hoses and connections
- Test blower motor operation
- Clean condenser coils
- Maintenance Notes
-
- Use only approved refrigerant
- Replace cabin air filter every 12,000 miles
- Inspect system for leaks annually
Warranty
- Basic
- Miles: 50000Years: 4Coverage: Parts and labor
- Powertrain
- Miles: 70000Years: 5Coverage: HVAC components
- Rust
- Miles: 120000Years: 12Coverage: Corrosion perforation
- Maintenance
- Miles: 30000Years: 3Coverage: Scheduled maintenance
Production Details
- Manufacturer
- Audi AG
- Manufacturing Process
-
- Robotic assembly
- Laser welding
- Computer-aided quality control
- Quality Control
- inspection: 100% system testingCertification: ISO 9001Testing: Environmental chamber testing
- Sustainability
-
- Recyclable materials
- Eco-friendly refrigerant
- Energy-efficient design
- Production Metrics
- Units Per Year: 200,000Facilities: Germany and international plantsWorkforce: Skilled engineering teams
Service Information for HVAC Service
Maintenance and service requirements specific to this component
- Inspect and replace cabin air filter
- Check refrigerant levels
- Inspect system hoses and connections
- Test blower motor operation
- Clean condenser coils
Use only approved refrigerant and follow proper safety procedures
- Inspect and clean condenser fins
- Check system for refrigerant leaks
- Test temperature sensor operation
- Inspect blower motor resistor
- Clean drain valves
Ensure proper system performance and efficiency
- Replace cabin air filter
- Inspect and replace serpentine belt
- Check compressor clutch operation
- Test heater core for leaks
- Perform system performance test
Address any issues before they become major problems
Frequently Asked Questions
Find answers to common questions about torque specifications
Q1 What is the refrigerant type and capacity for the 2005-2008 Audi A4 HVAC system?
What is the refrigerant type and capacity for the 2005-2008 Audi A4 HVAC system?
The 2005-2008 Audi A4 HVAC system uses R134a refrigerant. The total system capacity is approximately 525 grams (18.5 ounces). Always refer to the under-hood label for exact specifications.
Q2 How do I reset the HVAC system after replacing the cabin air filter?
How do I reset the HVAC system after replacing the cabin air filter?
To reset the HVAC system, turn the ignition to the 'ON' position without starting the engine. Press and hold the 'ECON' and 'AUTO' buttons simultaneously for 5 seconds until the display flashes. This resets the system and ensures proper airflow calibration.
Q3 What is the recommended interval for servicing the HVAC system?
What is the recommended interval for servicing the HVAC system?
Audi recommends inspecting the HVAC system every 20,000 miles or 2 years, whichever comes first. This includes checking refrigerant levels, cleaning the evaporator and condenser coils, and inspecting the blower motor and cabin air filter.
Q4 Why is there a musty smell coming from the HVAC vents?
Why is there a musty smell coming from the HVAC vents?
A musty smell is often caused by mold or bacteria growth in the evaporator core. This can be resolved by performing an HVAC system cleaning using an approved evaporator cleaner and replacing the cabin air filter. Regular maintenance can prevent this issue.
Q5 What is the function of the HVAC control module in the Audi A4?
What is the function of the HVAC control module in the Audi A4?
The HVAC control module regulates temperature, airflow, and distribution based on inputs from sensors and user settings. It communicates with the vehicle's CAN bus system to ensure optimal performance and energy efficiency.
Factory Service Resources
Access official service manuals, technical documents, and repair guides. These resources provide detailed procedures, specifications, and diagrams directly from the manufacturer.
Audi A4 HVAC System Service Manual
Coming SoonOfficial service manual detailing HVAC system components, diagnostics, and repair procedures for the 2005-2008 Audi A4.
Refrigerant Handling and Safety Guide
Coming SoonComprehensive guide on handling R134a refrigerant, including safety precautions, proper charging procedures, and environmental regulations.
Cabin Air Filter Replacement Tutorial
Coming SoonStep-by-step video tutorial on replacing the cabin air filter in the 2005-2008 Audi A4, including tips for resetting the HVAC system.
HVAC System Troubleshooting Guide
Coming SoonDetailed troubleshooting guide for common HVAC issues in the Audi A4, including diagnostic codes and repair solutions.
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