Data centre · Ventilation
Ventilation in data centre: what the SRI measures
Ventilation is about demand-controlled ventilation: more air when more people are present or CO2 rises, less when a room is empty. Heat recovery, free cooling with outdoor air and air-quality reporting count as well.
In short
- 1This page shows how the Smart Readiness Indicator (SRI) assesses the ventilation domain for datacenters.
- 2Datacenters focus on cooling and free cooling using outside air, not comfort ventilation for occupants.
- 3The ventilation domain carries a weighting factor of 2 out of 3 possible weights for this building type, because airflow and heat removal directly affect cooling energy consumption.
Weight of this domain for this building type
Which services count
| Service | Lowest level | Highest level | Advice |
|---|---|---|---|
| Supply air flow control at the room level V-1a · A · 5 levels | No ventilation system or manual control | Local Demand Control based on air quality sensors (CO2, VOC, ...) with local flow from/to the zone regulated by dampers | level 2 or higher |
| Air flow or pressure control at the air handler level V-1c · 5 levels | No automatic control: Continuously supplies of air flow for a maximum load of all rooms | 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) | – |
| Heat recovery control: prevention of overheating V-2c · 3 levels | Without overheating control | Modulate or bypass heat recovery based on multiple room temperature sensors or predictive control | – |
| Supply air temperature control at the air handling unit level V-2d · 4 levels | No automatic control | Variable set point with load dependant compensation. A control loop enables to control the supply air temperature. The setpoint is defined as a function of the loads in the room | – |
| Free cooling with mechanical ventilation system V-3 · 4 levels | No automatic control | H,x-directed control: The amount of outside air and recirculation air are modulated during all periods of time to minimize the amount of mechanical cooling. Calculation is performed on the basis of temperatures and humidity (enthalpy) | – |
| Reporting information regarding IAQ V-6 · A · 4 levels | None | Real time monitoring & historical information of IAQ available to occupants + warning on maintenance needs or occupant actions (e.g. window opening) | level 2 or higher |
Worked example
If everything in this domain is at level 0, the domain contributes nothing. At the highest level for all services, the indicative total score for this building type rises by about 17 percentage points (from 27 to 44 percent, with all other domains at level 1).
Why does ventilation count for a datacenter?
A datacenter consumes energy mainly for cooling and electricity. Few people occupy the space, so comfort ventilation plays a minor role.
Yet the ventilation domain carries significant weight in the Smart Readiness Indicator (SRI) for this building type. Airflow rate, air handling, and free cooling directly determine how much mechanical cooling is needed.
Which smart-ready services are assessed?
The SRI examines six smart-ready services within ventilation: a service is a building function that can be automated at different levels.
- V-1a and V-1c: airflow rate control at room level and at the air handling unit level, which supplies and treats air.
- V-2c and V-2d: heat recovery control and supply air temperature control, to prevent overheating and save energy.
- V-3: free cooling, using cool outside air instead of mechanical cooling.
- V-6: air quality reporting, including maintenance alerts.
Each service has functionality levels from 0 to 4. Level 0 means no automatic control; level 4 represents the most advanced, demand-driven operation.
What does a high level for free cooling mean in practice?
Service V-3 concerns using outside air to replace or reduce mechanical cooling. Level 3 uses both temperature and humidity to control outside air deployment.
For a datacenter, this can enable cooling without compressors for much of the year. This significantly reduces electricity consumption.
How does this domain relate to the rest of the building?
The heating, hot water, and building envelope domains play minimal roles in the SRI score for a datacenter. Monitoring and flexibility, for example through batteries and backup power, carry more weight.
Ventilation forms a link between cooling and energy management, explaining why it carries a weighting factor of 2 out of 3 for this building type.
What this means for you
- Owner
- Have the existing airflow rate control, heat recovery, and free cooling systems assessed for functionality level, because small improvements in this domain can noticeably lower cooling energy consumption. A higher ventilation score also contributes to a better class in the Smart Readiness Indicator, which is relevant now that the European Commission is expected to make the SRI mandatory for larger non-residential buildings.
- Tenant
- As a user of server rooms, you will notice little from this domain, because ventilation in a datacenter concerns cooling equipment, not human comfort. You do benefit indirectly from more stable temperatures and lower energy costs when free cooling and heat recovery are well controlled.
- Advisor
- When assessing, focus on the interconnection between V-1c, V-2d, and V-3, because these services together determine how efficiently air handling and free cooling work together. Also check whether air quality reporting (V-6) is genuinely linked to maintenance alerts, as this often makes the difference between level 2 and level 3.
Next step
Want to know where your building stands?