Smart-ready service V-1c · Ventilation
Air flow or pressure control at the air handler level
In short
- 1This page covers service V-1c, the control of air flow rate or pressure at the level of the air handling unit within the Ventilation domain.
- 2The service has five functionality levels, ranging from no automatic control to automatic flow rate or pressure control with pressure reset.
- 3This service does not count towards method A, the simplified measurement method of the Smart Readiness Indicator (SRI).
The levels
Level 0
No automatic control: Continuously supplies of air flow for a maximum load of all rooms
Level 1
On off time control: Continuously supplies of air flow for a maximum load of all rooms during nominal occupancy time
Level 2
Multi-stage control: To reduce the auxiliary energy demand of the fan
Level 3
Automatic flow or pressure control without pressure reset: Load dependent supplies of air flow for the demand of all connected rooms
Level 4
Automatic flow or pressure control with pressure reset: Load dependent supplies of air flow for the demand of all connected rooms (for variable air volume systems with VFD)
What does service V-1c measure?
Service V-1c assesses how intelligently a building controls air flow rate or pressure at the level of the air handling unit. This is the central device that supplies and extracts air for part of the building.
The service falls under the Ventilation domain, one of nine domains of the Smart Readiness Indicator (SRI). Each domain contains multiple smart-ready services that together determine how prepared a building is for smart, automated operation.
What do the five levels mean?
Level 0 means no automatic control. The air handling unit supplies air continuously as if all spaces are fully occupied.
Level 1 adds scheduled on-off control. The system still delivers a constant air flow, but only during the set occupancy period.
Level 2 introduces stepped control. This reduces the auxiliary energy consumption of the fan by adjusting the flow rate in steps.
Level 3 and 4 go further with automatic flow rate or pressure control. At level 3, the system adjusts air supply to match the actual demand of all connected spaces, without pressure reset. Level 4 does the same with pressure reset, designed for variable-volume systems with a frequency controller.
Why does this service not count towards method A?
The Smart Readiness Indicator has two measurement methods. Method A is the simplified version with 27 smart-ready services, method B is the full version with 54 services.
Service V-1c belongs only to method B. Buildings assessed using method A therefore receive no score for this specific ventilation function.
This does not mean the function is unimportant. It means that a more detailed assessment is needed to include this service in the building's final class.
Relevant for these building types
Next step
Want to know where your building stands?