All About Variable Air Volume Unit Vav Box: Composition, Performance Metrics, and Common Applications

Types of Variable Air Volume (VAV) Boxes

A Variable Air Volume (VAV) box is a critical component of modern HVAC systems designed to optimize indoor climate control. It dynamically adjusts the volume of conditioned air delivered to a specific zone—such as a room or office—based on real-time heating, cooling, and occupancy demands. By modulating airflow rather than constantly cycling the system on and off, VAV boxes significantly enhance energy efficiency, reduce operational costs, and provide precise thermal comfort across diverse environments including commercial offices, hospitals, educational institutions, and high-end residential buildings.

There are several types of VAV boxes, each engineered for specific applications, performance requirements, and building automation levels. Understanding their differences helps in selecting the right system for optimal comfort and efficiency.

Standard VAV Box

The most fundamental type, featuring a control damper and an airflow sensor to regulate air delivery based on thermostat input.

Advantages

• Simple, reliable design with minimal components
• Cost-effective installation and maintenance
• Effective for single-condition zones with stable thermal loads
• Widely compatible with standard HVAC controls

Limitations

• Limited ability to handle varying temperature needs within a zone
• No reheating capability, which may lead to overcooling in perimeter areas
• Performance can fluctuate with changes in duct pressure

Best for: Interior offices, conference rooms, retail spaces with consistent cooling demands

Reheat VAV Box

Equipped with a downstream reheat coil (electric or hot water), allowing conditioned air to be reheated before delivery.

Advantages

• Prevents overcooling in perimeter zones during winter
• Provides precise temperature control in mixed-load environments
• Improves humidity control and occupant comfort
• Ideal for spaces with solar gain or varying occupancy

Limitations

• Higher energy consumption due to reheating
• Increased installation and maintenance costs
• Requires additional piping or electrical connections

Best for: Perimeter offices, lobbies, kitchens, and areas with fluctuating thermal loads

Dual-Duct VAV Box

Utilizes two separate ducts—one for cold air and one for hot air—mixing them to achieve the desired supply temperature.

Advantages

• Offers exceptional temperature control flexibility
• Can simultaneously heat and cool different zones
• Ideal for buildings with both north and south-facing exposures
• High responsiveness to changing load conditions

Limitations

• Complex ductwork increases space and installation requirements
• Higher initial cost and energy use
• Less energy-efficient compared to single-duct systems

Best for: Large institutional buildings like hospitals, universities, and laboratories

Fan-Powered VAV Box

Includes an integrated fan that boosts airflow, especially during low-speed operation or when the main system is off.

Advantages

• Maintains consistent airflow even at low VAV box settings
• Can provide ventilation during unoccupied periods
• Often includes reheat capabilities for added comfort
• Reduces noise from duct pressure fluctuations

Limitations

• Higher maintenance due to moving fan parts
• Additional energy use from auxiliary fan
• Increased ceiling space requirement for installation

Best for: Zones requiring constant air circulation, such as private offices, restrooms, or long corridors

Pressure-Independent VAV Box

Features a built-in flow-measuring station and automatic flow regulator to maintain precise airflow regardless of system pressure changes.

Advantages

• Delivers consistent airflow despite duct pressure variations
• Superior temperature control and occupant comfort
• Enhances energy efficiency by avoiding over-airflow
• Self-balancing—reduces need for manual system tuning

Limitations

• Higher initial cost compared to standard VAV boxes
• More complex controls require skilled commissioning
• Potential for sensor drift over time if not maintained

Best for: High-performance buildings, LEED-certified facilities, and mission-critical environments

Smart VAV Box

Integrates IoT connectivity, advanced sensors, and digital controls for real-time monitoring and adaptive performance.

Advantages

• Enables remote monitoring and diagnostics
• Supports predictive maintenance and fault detection
• Integrates with building automation and energy management systems
• Adapts to occupancy patterns using AI or scheduling

Limitations

• Significant upfront investment and IT integration needs
• Requires cybersecurity considerations for networked devices
• Dependent on stable communication infrastructure

Best for: Smart buildings, data centers, and future-ready commercial developments

Type	Temperature Control	Energy Efficiency	Complexity	Best Application
Standard VAV	Basic	High	Low	Interior zones with uniform cooling needs
Reheat VAV	Advanced	Moderate	Medium	Perimeter zones with heating/cooling variability
Dual-Duct VAV	Excellent	Moderate	High	Hospitals, labs, large mixed-use buildings
Fan-Powered VAV	Good	Medium	Medium	Zones needing constant airflow or reheat
Pressure-Independent VAV	Excellent	Very High	High	High-efficiency buildings, critical environments
Smart VAV	Exceptional	Very High	Very High	Intelligent buildings, IoT-enabled campuses

Expert Tip: When selecting a VAV box, consider not only the current building use but also future flexibility. Pressure-independent and smart VAV systems offer better adaptability for space reconfiguration and evolving occupancy patterns, providing long-term value despite higher initial costs.

Function and Features of Variable Air Volume (VAV) Boxes

Variable Air Volume (VAV) boxes are essential components in modern HVAC (Heating, Ventilation, and Air Conditioning) systems, providing precise temperature and airflow control in commercial and residential buildings. Unlike constant air volume (CAV) systems, VAV boxes modulate the amount of conditioned air delivered to a space based on real-time demand, ensuring optimal thermal comfort while significantly improving energy efficiency. By delivering only the necessary volume of air, VAV systems reduce fan energy consumption and enhance indoor air quality.

Core Functions of VAV Boxes

Dynamic Airflow Regulation

VAV boxes continuously adjust airflow in response to room conditions. When a space requires cooling or heating, the system increases airflow; when the desired temperature is reached, airflow is reduced. This modulation prevents over-conditioning and minimizes energy waste, making VAV systems ideal for spaces with fluctuating occupancy or varying thermal loads.

Energy Efficiency

By varying airflow instead of running fans at full capacity constantly, VAV systems reduce electricity usage by up to 30–50% compared to traditional HVAC setups. This not only lowers operational costs but also reduces carbon emissions, supporting sustainability goals in green building design.

Zoned Climate Control

VAV boxes enable independent temperature control in different zones of a building. For example, offices on the sunny side of a building can receive more cooling, while shaded areas operate at lower fan speeds. This zoning capability enhances occupant comfort and allows facility managers to tailor environmental conditions to specific needs.

Noise Reduction

Since VAV systems operate at variable fan speeds, they generate less noise during low-demand periods. Combined with acoustic liners and proper duct design, VAV boxes contribute to quieter indoor environments—critical in settings like hospitals, schools, and office buildings.

Key Components and Their Roles

Dampers: The heart of the VAV box, dampers regulate airflow by opening or closing in response to control signals. Typically made from galvanized steel or aluminum, these precision-engineered components ensure accurate modulation of air delivery. Integrated with feedback mechanisms, they maintain consistent performance over time and respond rapidly to thermostat inputs for tight temperature control.

Actuators (Motors): Electric or pneumatic actuators drive the damper movement. Modern VAV systems use modulating actuators that allow fine-tuned control—adjusting the damper position incrementally rather than simply on/off. These motors are designed for quiet, reliable operation and can respond within seconds to changes in room conditions.

Sensors: Temperature, pressure, and sometimes CO₂ sensors provide real-time data to the building management system (BMS). A critical component is the airflow sensor inside the VAV box, which measures actual air volume and ensures the system maintains the required pressure and flow rate. This closed-loop feedback enables highly efficient and responsive control.

Thermostat and Control System: The thermostat acts as the user interface, allowing occupants or building automation systems to set desired temperatures. It communicates with the VAV controller, which processes sensor data and adjusts damper position accordingly. Advanced systems integrate with smart building platforms for remote monitoring, scheduling, and predictive maintenance.

Air Filters: Located at the inlet of many VAV units, filters remove dust, allergens, and particulate matter from the supply air. Maintaining clean filters is crucial—clogged filters increase static pressure, reduce airflow efficiency, and strain the HVAC system. Regular replacement (typically every 3–6 months) ensures consistent performance and indoor air quality.

Heating/Cooling Coils (Reheat or Fan-Powered Models): Some VAV boxes include hot water, steam, or electric reheat coils to warm the air when cooling-only mode would make the space too cold. Fan-powered VAV boxes may also include small fans and coils to boost airflow or provide localized heating, offering greater flexibility in complex zoning applications.

Component	Primary Function	Impact on System Performance
Dampers	Regulate airflow volume into the space	Directly affects temperature accuracy and energy use
Actuators	Control damper positioning	Enables precise, responsive airflow modulation
Airflow Sensors	Measure actual air delivery	Ensures system meets design specifications and efficiency targets
Thermostat	Provides temperature setpoint input	Drives occupant comfort and system responsiveness
Air Filters	Remove contaminants from supply air	Improves indoor air quality and protects internal components
Reheat Coils	Add supplemental heating if needed	Prevents overcooling in perimeter zones during winter

Benefits of VAV Box Systems

• Energy Savings: Reduces fan and chiller energy by matching airflow to actual demand.
• Improved Comfort: Maintains consistent temperatures across multiple zones with minimal fluctuations.
• Scalability: Easily integrated into large building automation systems for centralized control.
• Flexibility: Adaptable to changing room usage, occupancy patterns, and seasonal conditions.
• Compliance: Helps meet energy codes and green building standards such as LEED, ASHRAE 90.1, and ENERGY STAR.

Important: Proper commissioning and regular maintenance are essential for optimal VAV box performance. Neglecting sensor calibration, damper lubrication, or filter replacement can lead to poor temperature control, increased energy use, and occupant discomfort. Always follow manufacturer guidelines and involve certified HVAC technicians during installation and servicing to ensure long-term reliability and efficiency.

Scenarios of Variable Air Volume (VAV) Unit Applications

Variable Air Volume (VAV) boxes are intelligent components of modern HVAC systems that dynamically adjust airflow to maintain optimal temperature, air quality, and energy efficiency across diverse environments. By modulating airflow based on real-time demand, VAV systems provide precise environmental control while significantly reducing energy consumption compared to constant air volume (CAV) systems. Below are key application scenarios where VAV technology delivers exceptional performance and operational benefits.

Commercial Office Spaces

VAV boxes are essential in large office buildings with mixed-use zones such as private offices, open-plan workstations, conference rooms, and executive suites. They enable zonal climate control, ensuring personalized comfort for different occupants and usage patterns.

• Private offices can be set to higher airflow for increased comfort during extended occupancy
• Open-plan areas receive balanced airflow to prevent hot or cold spots
• Conference rooms utilize occupancy sensors to deliver conditioned air only when in use, saving energy during idle periods
• Integration with Building Management Systems (BMS) allows scheduling based on work hours and after-hours settings

Energy-saving insight: Demand-based airflow control in offices can reduce HVAC energy use by up to 30%.

Hospital Buildings

Hospitals require strict environmental control for patient safety, infection prevention, and regulatory compliance. VAV systems are deployed in patient rooms, operating theaters, laboratories, and isolation units to maintain precise temperature, humidity, and pressure conditions.

• Specialized VAV boxes with HEPA filtration ensure removal of airborne pathogens in critical care areas
• Pressure-dependent VAVs maintain negative pressure in isolation rooms to contain contaminants
• Positive pressure is maintained in operating rooms to prevent unfiltered air ingress
• Real-time monitoring and alarms ensure continuous compliance with healthcare standards (e.g., ASHRAE 170)

Critical application: VAVs with fail-safe modes ensure uninterrupted airflow during power fluctuations or emergencies.

Schools and Universities

Educational institutions benefit from VAV systems in classrooms, lecture halls, science labs, and auditoriums. These spaces experience fluctuating occupancy and varying thermal loads, making adaptive airflow essential for comfort and air quality.

• VAV boxes with CO₂ sensors detect occupancy levels and introduce fresh outdoor air when needed (Demand-Controlled Ventilation)
• Labs use specialized VAVs to manage fume hood exhaust and maintain safe indoor air quality
• Auditoriums receive higher airflow during events and reduced airflow when vacant
• Integration with school schedules optimizes energy use during holidays and weekends

Health impact: Improved ventilation reduces absenteeism by minimizing airborne illness transmission.

Shopping Malls and Hotels

Large public spaces such as hotel lobbies, ballrooms, restaurants, and mall atriums have highly variable occupancy and solar heat gain. VAV systems maintain consistent comfort while adapting to changing conditions.

• Airflow is increased during peak hours (e.g., weekends, events) and reduced during low-traffic periods
• Guest rooms use VAV terminals with thermostats for individual climate control
• CO and CO₂ sensors monitor air quality in parking areas and dining zones
• Energy recovery ventilators (ERVs) can be paired with VAVs to precondition incoming air efficiently

Guest experience: Seamless temperature control enhances comfort and satisfaction in hospitality environments.

Data Centers

Data centers generate significant heat from servers and networking equipment. VAV boxes play a crucial role in maintaining stable thermal conditions to prevent overheating and ensure uptime.

• VAV systems deliver precise cooling to server racks based on real-time temperature feedback
• Modulating airflow prevents hot spots and reduces the risk of hardware failure
• During low computational loads, airflow is reduced to conserve fan energy
• Integration with Data Center Infrastructure Management (DCIM) systems enables predictive cooling adjustments

Efficiency gain: VAV-based cooling can reduce data center HVAC energy consumption by 20–40%.

Manufacturing Plants

Industrial facilities have diverse thermal and ventilation needs across production lines, clean rooms, warehouses, and employee areas. VAV systems provide flexible, responsive airflow management.

• Production zones with high heat output receive increased cooling during operation
• Clean rooms use VAVs with filtration to maintain ISO-certified air quality standards
• Quick-response VAV actuators adapt to sudden changes in process heat or occupancy
• Waste heat recovery systems can be integrated to reuse thermal energy

Operational benefit: Adaptive airflow improves worker comfort and productivity in demanding environments.

Professional Insight: When designing or specifying VAV systems, always consider integration with building automation systems (BAS), sensor accuracy, and maintenance accessibility. Proper commissioning and regular calibration ensure long-term performance, energy savings, and occupant comfort. For critical environments like hospitals and data centers, redundant controls and fail-safe mechanisms are strongly recommended.

Application	Key VAV Features	Primary Benefits	Special Requirements
Commercial Offices	Occupancy sensing, zoning, BMS integration	Energy savings, personalized comfort	Scheduling, quiet operation
Hospitals	Pressure control, HEPA filtration, fail-safe	Infection control, regulatory compliance	ASHRAE 170 compliance, redundancy
Schools & Universities	CO₂ monitoring, demand-controlled ventilation	Improved air quality, reduced absenteeism	Durability, ease of maintenance
Hotels & Malls	High airflow capacity, occupancy-based control	Guest comfort, energy efficiency	Aesthetic integration, noise control
Data Centers	Precision temperature control, fast response	Equipment protection, uptime assurance	Redundant sensors, tight tolerances
Manufacturing Plants	Rugged construction, rapid modulation	Process stability, worker safety	Dust resistance, high-temperature tolerance

Additional Considerations for VAV System Success

• Commissioning: Proper setup and calibration are critical for optimal performance and energy savings
• Noise Control: VAV boxes should include acoustic liners and dampers to minimize airflow noise in quiet spaces
• Maintenance Access: Design for easy filter replacement and sensor cleaning to ensure long-term reliability
• Control Algorithms: Advanced proportional-integral-derivative (PID) controls improve response accuracy
• Energy Codes: Modern VAV systems help meet stringent energy standards like ASHRAE 90.1 and LEED certification

How to Choose a Variable Air Volume (VAV) Box: A Comprehensive Guide

Selecting the right Variable Air Volume (VAV) box is a critical step in designing or upgrading a commercial HVAC system. VAV boxes regulate airflow to individual zones by modulating damper positions based on temperature demands, enhancing energy efficiency, occupant comfort, and system flexibility. However, choosing the appropriate VAV box requires careful evaluation of several technical and operational factors. This guide outlines the key considerations to help engineers, contractors, and facility managers make informed decisions when specifying VAV systems.

Important Note: Incorrect VAV box selection can lead to poor temperature control, increased energy consumption, occupant discomfort, and system noise. Always consult HVAC design specifications, building load calculations, and manufacturer data before finalizing your selection.

Key Factors in VAV Box Selection

1. Design and Configuration

   The physical and functional design of a VAV box must align with the architectural layout, ceiling space, and HVAC zoning strategy. Common configurations include single-duct, dual-duct, bypass, fan-powered, and reheat (electric or hot water) models. For example:

   • Fan-powered VAV boxes are ideal for zones with long duct runs or where maintaining positive pressure is critical.
   • Bypass VAV systems maintain constant total airflow but are less energy-efficient than modern non-bypass designs.
   • Series vs. parallel fan-powered units differ in airflow sequencing and should be selected based on ventilation requirements and control complexity.

   Ensure the VAV box design supports proper integration with ductwork, access for maintenance, and compatibility with ceiling types (e.g., drop ceilings, open plenums).

2. Damper Arrangement and Control

   The damper is the heart of the VAV box, responsible for modulating airflow. The arrangement—such as opposed-blade or single-blade dampers—affects airflow precision, turndown ratio, and leakage rates.

   • Opposed-blade dampers provide superior airflow control and lower leakage, making them suitable for high-performance buildings.
   • Motorized actuators should offer proportional or modulating control for smooth response to temperature changes.
   • Look for low-leakage dampers (<5% at maximum differential pressure) to improve energy efficiency and zone control accuracy.

   Proper damper calibration and linkage design are essential for long-term reliability and quiet operation.

3. Size and Capacity

   VAV box size must be matched to the airflow requirements (CFM or L/s) of the zone it serves. Oversized units lead to short cycling and poor temperature control, while undersized units cannot meet heating or cooling loads.

   • Use detailed load calculations (e.g., ACCA Manual J or equivalent) to determine minimum and maximum airflow needs.
   • Consider the turndown ratio—the ratio of maximum to minimum airflow. A higher turndown (e.g., 10:1 or 20:1) allows better part-load performance and energy savings.
   • Ensure the box can handle the static pressure range of the duct system (typically 0.5" to 3.0" w.g.).

   Physical dimensions must also allow for installation in plenum spaces, so verify clearances for wiring, sensors, and service access.

4. Material Construction

   VAV boxes are typically constructed from galvanized steel, aluminum, or insulated composite materials. The choice impacts durability, acoustic performance, condensation resistance, and overall cost.

   • Galvanized steel offers strength and corrosion resistance, ideal for standard applications.
   • Insulated VAV boxes reduce noise transmission and prevent condensation in humid environments.
   • Aluminum is lightweight and corrosion-resistant, often used in cleanrooms or corrosive environments.

   For high-noise-sensitive areas (e.g., offices, hospitals), select units with acoustic lining or external insulation to minimize sound breakout.

5. Control Options and Intelligence

   Modern VAV boxes come with integrated controllers that communicate via analog (0–10V, 4–20mA) or digital protocols (BACnet MS/TP, BACnet IP, Modbus).

   • Standalone controllers are cost-effective for simple applications.
   • Networked VAV controllers enable centralized monitoring, fault detection, and demand-controlled ventilation (DCV).
   • Look for features like auto-calibration, airflow verification, and occupancy-based setback scheduling.

   Ensure the control system supports integration with your Building Automation System (BAS) for optimal performance and diagnostics.

6. System Compatibility and Integration

   A VAV box does not operate in isolation—it must seamlessly interface with thermostats, sensors, ductwork, air handlers, and the central control system.

   • Verify compatibility with existing BAS protocols and sensor types (e.g., temperature, CO₂).
   • Check electrical requirements (e.g., 24V AC vs. 24V DC) and wiring standards.
   • Ensure the VAV controller can accept input from room sensors and output signals to reheat valves or fan motors.

   For retrofits, consider retrofit kits or universal controllers that can work with legacy systems.

VAV Box Type	Best Applications	Key Advantages	Considerations
Single-Duct Standard	Office spaces, classrooms	Simple design, cost-effective	Limited reheat capability; may require separate heating
Single-Duct Reheat	Perimeter zones with cooling and heating needs	Precise temperature control with electric/hot water reheat	Higher energy use due to reheating; requires heating source
Fan-Powered (Parallel)	Zones with high ventilation needs	Improved ventilation, better mixing	Higher noise and maintenance; consumes additional power
Fan-Powered (Series)	Applications requiring constant fan operation	Excellent air mixing, consistent airflow	Higher initial cost and energy use
Bypass VAV	Older systems, constant volume retrofit	Simple integration with existing systems	Inefficient—wastes fan energy; not recommended for new builds

Expert Tip: Always perform airflow balancing and control calibration after installation. Use a calibrated airflow hood or pneumatic probe to verify actual airflow against setpoints. This ensures the VAV system operates as designed and maintains occupant comfort and energy efficiency.

Additional Selection Recommendations

• Review manufacturer submittals, performance data, and sound ratings before finalizing your selection.
• Consider lifecycle costs, not just upfront price—energy-efficient, low-maintenance units save money over time.
• Ensure the VAV box has accessible test ports for airflow measurement and diagnostics.
• Choose units with field-proven reliability and strong technical support from the manufacturer.
• For green building projects (e.g., LEED, BREEAM), select VAV boxes that support demand-controlled ventilation and energy recovery integration.

Choosing the right VAV box is a balance of technical performance, system integration, and long-term operational goals. By carefully evaluating design, capacity, controls, and compatibility, you can ensure optimal comfort, efficiency, and reliability in your HVAC system. When in doubt, consult with a licensed mechanical engineer or HVAC specialist to validate your selection against project-specific requirements.

Variable Air Volume (VAV) Box: Frequently Asked Questions

Q1: What are the different types of VAV boxes?

VAV (Variable Air Volume) boxes come in several configurations, each designed for specific HVAC applications and control requirements. The primary types include:

• Single Duct VAV Box: This is the most common type, which modulates airflow to a single zone based on temperature demand. It uses a damper to vary the volume of conditioned air supplied from a central air handling unit. Ideal for individual offices or rooms with consistent cooling needs.
• Multi-Duct (or Dual Duct) VAV Box: These systems have separate ducts for hot and cold air streams, allowing precise temperature control by mixing airflow. Though less common today due to higher energy use, they are useful in spaces with highly variable thermal loads.
• Parallel Fan-Powered VAV Box: Incorporates a small fan that operates in parallel with the main supply airflow. It boosts air movement during reheat cycles, improving efficiency and comfort, especially in perimeter zones with heating needs.
• Series Fan-Powered VAV Box: Features an integral fan that runs whenever the zone requires conditioning, providing constant airflow regardless of main duct pressure. Suitable for spaces requiring tight airflow control.
• Bypass VAV Box: Redirects excess air back to the return system when demand is low, maintaining stable duct pressure but typically less energy-efficient than modern alternatives.

Each type integrates with building automation systems (BAS) to optimize comfort and energy use based on occupancy, time of day, and seasonal conditions.

Q2: What does a VAV box do?

A VAV box is a critical component of modern HVAC systems that dynamically controls the amount of conditioned air delivered to a specific zone—such as an office, conference room, or retail space—to maintain desired temperature and air quality. Here’s how it works:

• Temperature Sensing: A thermostat or sensor detects the current room temperature and compares it to the setpoint.
• Flow Modulation: Based on the signal from the controller, the VAV box adjusts its internal damper to increase or decrease airflow. For example, during cooling, more cold air is delivered; when the room reaches the setpoint, airflow reduces.
• Energy Efficiency: By varying airflow instead of running at full capacity constantly, VAV systems significantly reduce fan energy consumption compared to constant volume systems.
• Duct Connection: The VAV box is installed within the supply ductwork and connected directly to the space via branch ducts, enabling localized climate control.
• Integration with Controls: Most VAV boxes communicate with a central building management system (BMS), allowing remote monitoring, scheduling, and diagnostics.

Advanced models may also include features like reheat coils (electric or hot water), sound attenuators, and airflow sensors to enhance performance and occupant comfort.

Q3: What is the difference between a VAV and a CAV box?

The key difference between Variable Air Volume (VAV) and Constant Air Volume (CAV) systems lies in how they manage airflow and temperature control. Below is a detailed comparison:

Feature	VAV Box	CAV Box
Airflow Delivery	Varies airflow based on real-time zone demand to maintain temperature.	Supplies a constant volume of air regardless of load changes.
Temperature Control	Adjusts airflow to regulate temperature; may include reheat for precision.	Controls temperature by changing air temperature (e.g., via reheat coils), not airflow.
Energy Efficiency	High—reduces fan and chiller energy by matching output to demand.	Lower—fans run at full speed; reheating wastes energy.
Zoning Capability	Excellent—each zone can be individually controlled.	Limited—typically serves multiple zones with uniform conditions.
System Complexity	Higher—requires dampers, sensors, and control algorithms.	Simpler—fewer components and controls.
Common Applications	Office buildings, hospitals, schools, and commercial spaces with variable occupancy.	Industrial facilities, labs, or areas requiring constant ventilation rates.

In summary, VAV systems offer superior comfort and energy savings in environments with fluctuating thermal loads, while CAV systems are better suited for applications where consistent airflow is more important than temperature precision. As a result, VAV technology has become the standard in most new commercial HVAC installations.