Supply air flow control at the room level

What is V-1a?

V-1a is a smart-ready service within the Ventilation domain of the Smart Readiness Indicator (SRI). The SRI is a European methodology that measures how well a building makes use of smart technology.

This service concerns the control of supply air flow rate at room level. That means: how much fresh air a room receives, and how this is managed.

V-1a is one of the services already assessed under method A. Method A is the simpler assessment variant with 27 services, compared to 54 services in the more detailed method B.

What levels are there?

The SRI assigns five functionality levels to V-1a, numbered from 0 to 4. Each level represents a different degree of control and technology.

• Level 0: no ventilation system, or a system that is operated manually.
• Level 1: time-based control, where ventilation switches on or off at fixed times.
• Level 2: control based on occupancy detection in the room.
• Level 3: central demand-controlled operation based on indoor air quality sensors, such as CO2, volatile organic compounds (VOCs) or humidity.
• Level 4: local demand-controlled operation based on indoor air quality sensors, where dampers regulate flow rate per zone.

The higher the level, the more precisely the system responds to the actual need for fresh air in a specific room.

Why does this count towards the score?

The SRI assesses each smart-ready service against seven impact criteria, such as energy efficiency and indoor air quality. Ventilation control directly affects comfort and health.

A higher functionality level for V-1a generally contributes better to the overall SRI score. The score is expressed as a percentage and falls into one of seven classes, ranging from below 20 percent to 90 to 100 percent.