Indoor air quality (IAQ) and smart ventilation have shifted from specialized concerns to core topics at recent AHR Expos and industry events. This analysis outlines how evolving regulations, AI-driven HVAC controls, and energy-efficiency mandates are influencing IAQ solutions across commercial, healthcare, education, and industrial projects for both new builds and retrofits.

IAQ and Smart Ventilation Take Priority

The 2024 AHR Expo in Chicago (January 22-24) brought together hundreds of HVACR exhibitors, with a marked emphasis on IAQ, ventilation, and building automation[1]. Education sessions focused on AI, advanced controls, and compliance with updated ventilation standards, confirming IAQ as a strategic priority in system design and facility operation.

Principal drivers behind this shift include:

  • Increased awareness of airborne infection risks post-COVID-19
  • Stricter ventilation and energy regulations in North America and Europe
  • Accelerated deployment of IoT sensors, cloud platforms, and AI in building automation
  • Decarbonization pressures on building owners to maintain comfort and health standards

HVAC accounts for approximately 38% of global building energy use[2]. As a result, improvements in IAQ must be balanced with energy consumption and operational costs.

Regulatory Drivers: EPBD 2024, ASHRAE 62.1, and 241

Regulation is the primary factor elevating IAQ and smart ventilation in product development and project specifications.

Europe: EPBD Recast and IEQ-Focused Ventilation Rules

The recast Energy Performance of Buildings Directive (EPBD), adopted in 2024, grants indoor environmental quality (IEQ)-including IAQ-equal priority with energy performance. It directly links ventilation, filtration, and monitoring requirements to EU decarbonization goals.

Key mandated changes for HVAC and controls design:

  • Building Automation and Control (BACS) Requirements
    Directive (EU) 2024/1275 compels non-residential buildings with heating and ventilation capacities above 290 kW to install BACS[3]. This mandates integration of ventilation control with building automation for large facilities.

  • IEQ and IAQ Monitoring
    New non-residential zero-emission buildings in the EU must include indoor air quality monitoring under EPBD 2024 provisions[4]. National interpretation will likely require tracking of CO₂, particulates, and other IAQ metrics in schools, offices, and healthcare environments.

  • Model Regulation and PM2.5 Thresholds
    Guidance from REHVA provides member states with templates for specifying pollutant limits and minimum ventilation rates. Model IEQ regulations cap indoor PM2.5 at 10 µg/m³ where outdoor air is not filtered[5]. This necessitates filtration upgrades and improved outdoor-air management.

  • Essential Role of Mechanical Ventilation and Recovery
    Eurovent recommends pairing airtight, energy-efficient envelopes with mechanical ventilation and heat/energy recovery, particularly during renovations, to maintain IAQ.[6]

For EU designers and facility managers, the immediate result is the need to document IAQ metrics-not just calculated ventilation rates-and integrate ventilation with BACS for ongoing monitoring.

North America: ASHRAE 62.1 Updates and Standard 241

ASHRAE standards, used globally, are shifting toward clearly defined and controllable IAQ requirements.

  • ASHRAE 62.1-2025: Ventilation for Acceptable IAQ
    ASHRAE 62.1-2025 introduces mandatory humidity limits, air-density corrections, defined demand-control sequences, and emergency ventilation controls[7]. Practical consequences include:

    • Expanded sequences for demand-controlled ventilation (DCV)
    • Precise requirements for humidity and air density in outdoor-air calculations
    • Defined emergency and atypical operation modes

  • ASHRAE 241-2023: Control of Infectious Aerosols
    ASHRAE 241-2023 specifies minimum equivalent clean airflow per person, integrating ventilation, filtration, and air cleaning for infection risk mitigation[8]. Designers balance:

    • Outdoor air ventilation
    • Filtration quality (e.g., MERV ≥13)
    • Supplemental air cleaning (e.g., UV-GI, HEPA units)

ASHRAE 241 is a key topic for schools and healthcare retrofits, where mitigation of infection risks is now a requirement.[9]

Together, EPBD and ASHRAE standards are steering the industry toward performance-based IAQ targets-verified with sensors and enforced through sophisticated HVAC controls.

Technology Stack: Sensing, Controls, and AI in Demand-Controlled Ventilation

Instrumentation: IAQ Sensing and Data Infrastructure

Smart IAQ and ventilation rely on accurate, continuous field data. The most common technologies exhibited at AHR and similar events include:

  • CO₂ sensors for occupancy and ventilation effectiveness
  • PM2.5/PM10 and VOC sensors for pollutant monitoring
  • Temperature and humidity sensors for comfort and mold prevention
  • Smart gateways (BACnet/IP, Modbus, MQTT) for BMS integration

High-grade particulate sensors, such as those from ION Science, are increasingly designed for direct integration with ventilation systems in commercial buildings.[10]

By 2024, about 31% of building IoT-connected devices are HVAC systems with smart control capacity[11]. This connectivity enables detailed IAQ monitoring at both zone and system levels.

Installers and system integrators must focus on:

  • Routing low-voltage and communication wiring for sensors
  • Verifying compatibility with existing BMS/BACS platforms or cloud services
  • Addressing cybersecurity for remote access and data handling

Control Strategies: Advancing from Schedules to DCV

Traditional ventilation often relies on static schedules and fixed air fractions. Smart IAQ systems now implement demand-controlled ventilation (DCV), modulating outdoor-air and recirculation rates based on CO₂ and VOC sensor data.

Recent research highlights DCV advantages:

  • Office DCV experiments have shown energy reductions of around 60% compared to constant-airflow systems without sacrificing IAQ[12]
  • Classroom simulations report 35% annual electricity savings using CO₂-optimized DCV versus fixed-rate ventilation[13]

Current DCV strategies showcased at industry events typically involve:

  • Zone-by-zone CO₂ control of dampers and air fractions
  • Occupancy-based setbacks with ASHRAE 62.1 minimum ventilation safeguards
  • Coupling with heat or energy recovery to maintain supply air quality and comfort

Commissioning and installation best practices include:

  • Ensuring correct sensor placement (to avoid dead zones)
  • Verifying control response and loop stability
  • Documenting outdoor-air minimums during low occupancy

AI-Enabled Optimization and Occupant-Centric Controls

AI and advanced analytics are prominent at trade events. These solutions leverage sensor and BMS data to refine setpoints and schedules in real time.

Key research examples:

  • Reinforcement Learning HVAC Controls: RL controllers for large VAV systems can reduce energy use and maintain comfort by adjusting setpoints dynamically.[15]
  • Occupancy-Based Optimization: A two-year study of occupancy-driven optimization delivered 6.1% building-wide energy savings under full occupancy[16] by integrating occupancy data, machine learning, and BAS interfaces.
  • Human-in-the-Loop and Personalized Comfort: Combining occupant feedback with predictive tools further enhances control performance.[2]

Commercially, these functions are typically implemented as add-ons to existing BMS platforms, supporting incremental rollout:

  • Begin with monitoring and fault detection
  • Layer in DCV and baseline optimization sequences
  • Add AI-driven optimization after data and commissioning issues are addressed

Energy-IAQ Trade-offs: Research and Standards Perspective

The core technical challenge is to optimize IAQ without excessive energy consumption. The consensus approach-reflected in recent standards and research-relies on dynamic control and localized air cleaning to prevent routine over-ventilation.

Current research shows:

  • Over-ventilation responses to health concerns significantly increase energy use and are not long-term solutions.[2]
  • Performance-based standards like ASHRAE 241 award credits for integrating ventilation, filtration, and air cleaning to achieve required clean airflow at lower outdoor-air volumes.[8]
  • DCV and occupancy optimization consistently demonstrate double-digit percentage energy reductions while meeting IAQ goals in offices and schools.

The following table summarizes key HVAC control approaches:

Control approach IAQ visibility Energy efficiency potential Complexity/commissioning effort Primary use case
Fixed outdoor-air fraction & schedules Low Low Low Legacy systems, small retrofits
CO₂-based DCV Medium Medium to High Medium Offices, classrooms, meeting rooms
Multi-sensor DCV High High Medium to High Schools, healthcare, high-density zones
AI-optimized HVAC High High High Large commercial, campuses, hospitals

Significant energy and performance gains typically require a robust sensing network and advanced control logic, although many facilities can achieve substantial benefits with targeted DCV upgrades.

Application Sectors: IAQ and Smart Ventilation in the Field

Schools and Universities

Education facilities face high, shifting occupancy and increased health scrutiny. Typical IAQ upgrades include:

  • CO₂-based DCV on AHUs or standalone units
  • Upgraded filters or fan-filter units in line with ASHRAE 241 standards[9]
  • Live IAQ dashboards for facility oversight

Studies indicate DCV lowers energy use while meeting CO₂ targets (aligned with EN 16798 and similar standards).[13] Modular fan-filter units presented at AHR Expo 2024 enable clean airflow improvements with minimal ductwork modifications.[9]

Healthcare and Laboratories

Hospitals and labs operate under strict infection-control and cleanliness mandates. ASHRAE 241 and sector-specific standards (e.g., ASHRAE 170) now shape ventilation design for waiting, treatment, and isolation spaces.[8]

Common retrofits are:

  • Upgrading AHU filtration to at least MERV 13 or higher
  • Adding local UV-GI or HEPA units to achieve clean airflow targets
  • Updating control sequences for "normal" and "infection-risk" operational modes per ASHRAE 241

Controls integration and reliable mode-switching logic are critical and frequent topics of discussion at industry panels on healthcare HVAC.

Commercial Offices and Retail

Offices and retail facilities now emphasize occupant-centric operations:

  • Occupancy analytics (counters, badge systems, Wi-Fi data) feeding air handling controls
  • DCV tailored for varying densities in open and closed spaces
  • Schedule optimization based on measured, not assumed, activity[16]

AI-based platforms help align IAQ and energy reporting with ESG and regulatory frameworks. Facility managers increasingly track both energy use and IAQ effectiveness.

Industrial and Process Facilities

Industrial environments focus on process ventilation and contaminant control. Smart IAQ adoption includes:

  • Distributed sensors for targeted pollutant detection
  • Variable-speed exhaust and make-up control based on real-time demand
  • Integrated dashboards for centralized IAQ and energy tracking

Interest is rising in leveraging energy recovery and real-time monitoring to avoid excess make-up air during production downtime.

Retrofit vs. New Construction: Implementation Pathways

New buildings typically incorporate IAQ at the design stage:

  • Early selection of IAQ sensors and communication interfaces
  • Operation sequences adhering to EPBD, EN 16798, ASHRAE 62.1, and 241
  • Linking ventilation, comfort, and energy management within the BMS

Retrofit projects generally proceed stepwise:

  1. Monitoring: Install CO₂ and specific pollutant sensors; integrate with existing BMS and visualize trends.
  2. Control: Implement DCV, verify ventilation minima, and tune setpoints.
  3. Optimization: Introduce analytics or AI for schedule and setpoint refinement.
  4. Deep retrofit: During equipment replacement, select components for continuous IAQ-centric operation.

With EPBD deadlines approaching for large buildings, delayed sensor and control upgrades risk creating non-compliant assets.

Key Points and Action Steps for HVAC Professionals

Key Insights

  • IAQ and ventilation have become essential design and operation criteria, driven by EPBD 2024, ASHRAE 62.1-2025, and ASHRAE 241.
  • Effective smart ventilation combines advanced sensing, DCV, and AI-driven optimization.
  • Dynamic ventilation strategies consistently deliver meaningful energy savings without compromising IAQ.
  • National adoption of updated codes will increasingly require documentation of actual IAQ, not just compliance by design.

Practical Steps for Designers, Retrofit Teams, and Operators

System designers and consultants:

  • Align calculations with current ASHRAE 62.1/62.2 or EN 16798 standards; check how local codes reference these documents.
  • Specify CO₂, PM2.5, humidity, and (as needed) VOC sensors-define placement and accuracy requirements.
  • Incorporate DCV and infection-control operational modes, referencing ASHRAE 241 if applicable.

Installers and commissioning professionals:

  • Plan integration of new sensors with existing BMS/BACS.
  • Test IAQ-related control loops (CO₂-based DCV, mode switching, humidity control) under typical conditions.
  • Document ventilation safeguards and verify that fault or failure states default to safe operation.

Facility managers:

  • Prioritize IAQ monitoring for buildings over 290 kW to comply with EPBD mandates.
  • Use IAQ and energy data to identify areas with ventilation imbalances and adjust as needed.
  • Consider incremental analytics or AI optimization after foundational controls are established.

Emerging IAQ and smart ventilation strategies showcased at AHR Expo confirm the trajectory: ventilation control will be increasingly data-driven and real-time. Incorporating IAQ data and advanced controls as standard practice positions professionals to meet regulatory, efficiency, and health requirements for 2024-2025 and beyond.

Frequently Asked Questions

How do smart IAQ systems differ from traditional BMS-controlled ventilation?

Traditional BMS typically uses fixed schedules and outdoor-air ratios, often relying solely on temperature (and occasionally CO₂) feedback. Smart IAQ systems deploy multiple IAQ sensors (CO₂, PM2.5, VOCs, humidity), integrate these data streams into control logic, and use analytics or AI to optimize ventilation in near-real time. This supports performance-based compliance with standards like ASHRAE 241 and EPBD, while minimizing excess energy use.

Does ASHRAE 241 require replacement of existing air-handling units?

ASHRAE 241 sets minimum equivalent clean airflow rates for infection mitigation but does not specify equipment type. Compliance can be achieved by upgrading filtration, controls, and adding air-cleaning devices to existing AHUs.[8] Many systems can be retrofitted to meet requirements without full equipment replacement.

What are typical energy savings from demand-controlled ventilation?

Reported savings vary by building, climate, and implementation. Building studies show energy reductions of one-third to over half with proper DCV design and commissioning compared to constant or fixed-rate ventilation, all while maintaining IAQ.[12] Realized savings depend on occupancy trends, sensor quality, and control tuning.

How should IAQ and smart ventilation be specified in new projects under EPBD 2024?

Design specifications should:

  • Reference national EPBD 2024 interpretations and EN 16798-1 for IAQ and ventilation design
  • Require continuous IAQ monitoring for non-residential zero-emission buildings, as mandated
  • Ensure building automation provides verified, adjustable ventilation to meet energy and IEQ goals[3]

Clear IAQ and controls specifications at the design stage enable compliance and future adaptability.

What data is needed to demonstrate compliance with IAQ and ventilation standards?

For compliance under IAQ or infection-control standards, best practices include logging:

  • Zone-level CO₂, and where relevant, PM2.5 and VOC measurements
  • Supply and outdoor airflow indicators (damper position, fan speed, or direct readings)
  • Core environmental variables (temperature, humidity)
  • System operating modes, including any "infection-risk" or elevated-ventilation periods

These records support regulatory audits and energy optimization efforts, and are increasingly expected for EPBD and ASHRAE compliance.