(Note: Opinions in the articles are of the authors only and do not necessarily reflect the opinion of the European Union).

Mechanical ventilation is essential for healthy and comfortable indoor spaces. It helps dilute pollutants, manage humidity, and support well-being. Yet, in many buildings, it still runs on fixed schedules, static settings, or manual intervention. That can be misaligned with reality: rooms are not always occupied as expected, uses change, and operation is rarely 'as designed'.

This short article offers a first look at EVIA’s upcoming white paper on smart ventilation and why it matters for the Energy Performance of Buildings Directive (EPBD) delivery. Smart ventilation closes the gap between design intent and real-world operation by shifting toward a performance-based approach: delivering the right air, at the right time, in the right place, while keeping energy use as low as possible.

As Europe raises requirements on indoor environmental quality and accelerates renovations, how ventilation performs in day-to-day operation becomes a policy issue, not just an engineering detail.

Why mechanical ventilation is back on the policy agenda

Europe is simultaneously pursuing better building energy performance and better indoor environmental quality. These objectives reinforce each other when ventilation is designed and operated well, but they can also clash when systems are poorly tuned or poorly understood.

Today’s context makes mechanical ventilation more visible to policymakers and market actors alike:

1. Indoor air quality (IAQ) is moving from awareness to requirements, guidance, and procurement criteria as a public interest topic, with clear links to health and productivity.
2. Energy affordability and decarbonisation goals require that buildings avoid unnecessary thermal and cooling losses.
3. Building renovation and modernisation often change the building’s 'air balance', meaning assumptions that held before a retrofit may no longer be valid, especially when the building envelope has been reinforced.
4. The revised EPBD implementation discussion is pushing the sector toward outcomes and operational performance, not only the nominal efficiency of components.

Against this backdrop, mechanical ventilation is not simply a technical subsystem. It is a lever that is indispensable for healthier spaces and energy performance, if it is controlled and verified in a way that reflects real building use.

The problem with fixed ventilation in real buildings

Fixed ventilation strategies are often based on simplified assumptions: stable occupancy, consistent schedules, predictable pollutant loads, and uniform use of spaces. In practice, buildings are dynamic. Occupancy patterns vary day by day, space utilisation changes, and maintenance quality differs widely.

This creates two common failure modes:

• Over-ventilation: more outdoor air than needed, leading to avoidable higher heating or cooling demand.
• Under-ventilation: insufficient incoming outdoor fresh air during high occupancy or high pollutant load, leading to poor IAQ that can harm health and fuel discomfort and complaints.

A third issue is equally important: lack of feedback. Many buildings cannot easily verify whether ventilation performance is being achieved over time. Without data and diagnostics, operators often rely on intuition or static setpoints, even when conditions have changed.

Smart ventilation is best understood as a way to deal with these risks by adding sensing, control logic, and verification that help systems track actual needs.

What 'smart ventilation' means

Smart ventilation is a mechanical ventilation approach that uses sensors, controls, and performance logic to continuously match airflow to real demand, to comply with IAQ requirements while minimising energy use to what is strictly necessary to do so. It can be implemented in centralised or decentralised systems; the key is the synergy control/verification. In practice, 'smart' is not a single feature. It is a combination of capabilities that work together:

• Demand-based control: Ventilation responds to real indicators of need, such as occupancy patterns and pollutant proxies (commonly CO₂, humidity, VOC indicators, particulate matter, depending on context).
• System coordination: Control sequences coordinate fans, dampers, terminals, heat recovery, and, in many buildings, the related heating and cooling effects. This matters because ventilation is tightly coupled to energy performance.
• Performance verification: Smart ventilation supports commissioning and ongoing checks. It enables operators to see whether the intended operation is being delivered and where adjustments are needed.
• Accessible data and interoperability: Smart ventilation works best when key data points can be accessed and integrated across building systems, rather than being locked into isolated interfaces.

This definition keeps the focus on outcomes: IAQ delivered reliably and efficiently, and systems that remain effective throughout time and as buildings change.

Benefits in residential and non-residential buildings

Smart ventilation creates value in both residential and non-residential buildings, but 'where it pays off most' can differ.

Residential buildings

In homes and multi-family buildings, Smart ventilation typically focuses on maintaining good IAQ and moisture management without running at unnecessary rates.

Common benefits include:

• More stable IAQ despite changing occupancy patterns, including home office and irregular schedules.
• Better humidity control, which supports comfort and helps reduce risks linked to excessive moisture.
• Moisture/Health protection and robustness with low user effort.  

Residential buildings also highlight an important point for policy: ventilation is not only about equipment. It is about operational settings, occupant interaction, and maintenance throughout time.

Non-residential buildings

In offices, schools, healthcare, and commercial buildings, occupancy variability and diversity of spaces make demand-based approaches particularly relevant.

Common benefits include:

• Strong energy-saving potential where occupancy peaks and off-peak periods are frequent. A meeting room ventilated at 'design day' flow even when empty wastes fan power and heating/cooling. The same room under-ventilated during a full workshop creates productivity loss.
• Operational confidence, by making IAQ measurable and manageable rather than uncertain.
• Improved maintenance decisions, because diagnostics can reveal drifting performance, faults, or misconfiguration.

In many non-residential buildings, Smart ventilation can also offer, to some extent, flexibility to the Grid or connect to Building Automation and Control Systems (BACS). This allows coordinated strategies, including demand response and load management, where appropriate.

Smart ventilation as a delivery mechanism for EPBD ambitions

The revised EPBD discourse reinforces what matters for ventilation: associating nominal design intent to measurable, operational outcomes. Smart ventilation fits this because it supports the delivery of the right airflow, and it makes IAQ and system operation visible and verifiable over time.

This is enabled by the most efficient technologies from an IAQ and energy-efficiency standpoints.

Requirements can focus on outcomes and basic capabilities, for example:

• minimum monitoring and verification of IAQ and ventilation operation;
• commissioning evidence that the system is set up to meet the intended performance;
• a minimum interoperable dataset (e.g., key IAQ indicators plus airflow/operating status) to avoid lock-in by creating dependencies on specific technologies or products and enable oversight;
• proportionate operational performance reporting, where building type and size justify it.

Seen this way, smart ventilation becomes a practical bridge between three domains often treated separately: indoor environmental quality, energy efficiency, and building automation.

What it takes to scale

Smart ventilation is not achieved by installing sensors alone. It requires a small set of enabling conditions and good practice choices that keep the approach robust and trustworthy.

Key enablers 

1. Clear targets and guidance for ventilation and IAQ performance. Targets do not need to be complicated, but they should focus on outcomes, such as air flow rates and IAQ levels, and ensure designers and operators share the same objective.
2. Commissioning and verification that is feasible at scale. Commissioning must be realistic for typical projects. Smart approaches can help by making checks easier and more continuous, but they still need a practical workflow.
3. Interoperable data expectations for key points. A modest 'minimum data set' for ventilation can reduce lock-in, simplify integration, and support consistent operation across building types.
4. Competence building across the value chain. Designers, installers, commissioners, facility managers, and owners all shape results. Policy can support training and accessible guidance.

Pitfalls to avoid 

1. Treating smart ventilation as a gadget. Without robust control sequences and commissioning, extra sensors can create complexity without improving outcomes.
2. Optimising one objective at the expense of the other. Energy-only optimisation risks under-ventilation. IAQ-only optimisation risks over-ventilation. Smart means balancing.
3. Creating fragile dependencies from specific technologies or products. Open, documented interfaces, avoiding unnecessary dependencies, and clear operational procedures matter. 

What policymakers and national agencies can do next

Smart ventilation can spread faster when policy and implementation frameworks make it easier to specify, verify, and operate performance.

Practical actions include:

• Embed performance-based ventilation thinking into national guidance and implementation measures.
• Encourage verification and monitoring approaches that are proportional to building type and risk, rather than one-size-fits-all burdens.
• Promote interoperable data expectations for key ventilation and IAQ points to support integration and avoid unnecessary lock-in due to non-interoperable technologies.
• Support competence building across design, commissioning, and operation, including clear templates and checklists.
• Align incentives so energy efficiency gains are rewarded when they demonstrably maintain indoor air quality.

These aspects ensure that the market can deliver the outcomes policy already targets.

Read more: EVIA’s 'Smart Ventilation' White Paper

This article has introduced smart ventilation as a practical way to deliver healthier indoor air while supporting energy efficiency through better control, verification, and interoperable data.

For readers who want the deeper layer, EVIA will present a 'Smart Ventilation' White Paper in the coming months, providing a shared framework for understanding smart ventilation across residential and non-residential applications. It explores the core functions of smart ventilation systems, the links to regulatory frameworks, and the collaboration and innovation needed to deploy reliable performance in Europe to scale.