Trial / Demo
During our recent webinar, Future‑Proofing Data Centre Delivery with Dynamic Simulation: Designing & Retrofitting for AI‑Driven Demand, we received an exceptional volume of technical questions from engineers, consultants, and data centre specialists across the globe.
With such a wide range of questions submitted during the session, it wasn’t possible to answer them all live. However, clear themes emerged around cooling strategies, HVAC modelling, performance metrics, regulatory compliance, and future ready design.
Below, our experts answer the most common questions, offering practical guidance on how IESVE and our end-to-end Data Centre Consulting Service can be used to model, analyse, and optimise modern data centres—particularly those facing increasing AI and high‑density computing demands.
Dynamic Simulation & IESVE Capabilities
What software was used for the dynamic analysis shown in the webinar?
All analysis presented was undertaken using the capabilities present in the current release of IESVE (2025). A design can look strong at peak yet still consume excess energy for many hours each year. Dynamic simulation closes this gap by generating the dynamic annualised PUE that reflects real climate conditions, actual load patterns, and true system behaviour.
Does the simulation account for full year (8760 hours) operation and different ASHRAE weather conditions?
Yes. The simulations shown were run over a full annual period using hourly weather data. IT load profiles can also be customised to reflect realistic operational variability, which is critical for accurate performance evaluation.
Is demand response management possible through dynamic simulation?
Yes, dynamic simulation can be used to assess the energy demand in response to varying IT equipment loads. IT Loads can be scheduled to reflect varying operation over time. IESVE can also simulate load shifting, IT turndown, and fan/pump VSD responses.
Can you model waste heat reuse efficiency through heat networks?
An IESVE energy model can help support an analysis of this type by producing hourly heat profiles for a district heat network (DHN) in order to assess feasibility and availability across the year. The VE can also model water to water heat pumps to include the energy demands to upgrade heat from the heat rejection loop to a district heating loop. Rather than modelling the entirety of a district heating loop the load can be represented via a scheduled load.
Cooling Technologies & High Density Data Hall
Which advanced cooling technologies are most commonly being modelled?
Webinar participants reported encountering a wide range of solutions, including:
IESVE can support analysis of all these approaches through a combination of ApacheSim, ApacheHVAC, and other integrated modules, depending on the level of detail required. Immersion cooling can be represented as a thermal load on the secondary loop, but VE does not explicitly model fluid tank behaviour. Our consulting team can guide through these analyses.
Can IESVE model direct‑to‑chip or liquid cooling systems?
Yes. At present, direct‑to‑chip cooling is typically modelled as a scheduled load on the chilled or warm water loop, allowing users to:
This approach enables meaningful comparison between air‑cooled, hybrid, and liquid‑cooled strategies. Ongoing software development is addressing modelling of server racks with explicit liquid cooling.
Is there a way to model CDUs for direct to chip/cold plate for liquid cooling? How do I show air-side vs liquid-side in internal loads?
Yes. A common workflow to show air-side vs liquid-side loads is to model:
Although the VE does not currently explicitly model CDUs for direct to chip/cold plate for liquid cooling we are however reviewing within our ongoing development path. Our Consultancy team are on hand to provide expertise on supporting routes.
How can you model FWS (Facility Water Supply) and TCS (Technology Coolant Supply) Temperatures within IESVE?
You can model FWS and TCS temperatures in IESVE (ApacheHVAC) by representing the cooling architecture as a primary/secondary water‑loop arrangement, mirroring how a CDU separates the facility water system from the technology cooling system. IES is currently developing a CDU Heat exchanger model.
The operating temperature of the Facility Water Supply (FWS) has a significant impact on the availability of free cooling. Increasing the supply temperature improves the temperature differential to ambient conditions, enabling heat rejection via dry coolers or cooling towers over a greater proportion of the year.
When mechanical cooling is required, a higher FWS temperature reduces chiller compressor lift, resulting in improved chiller efficiency and lower energy consumption.
The impact of this can be modelled using the VE.
Why was the water use intensity for evaporative cooling so much lower than for the water-cooled chiller in the "Performance Metric Trade-off Evaluation" example you gave?
The primary reason was that the water-cooled chiller solution did not benefit from any free cooling and required mechanical cooling year-round relying on cooling towers. By contrast the system designed to meet the peak demand using Direct Evaporative cooling could sufficiently maintain the design criteria for 85% of the year using outdoor air alone with the evaporative cooling only required for 15% of the operational hours. This is a strength of using ApacheHVAC coupled to the dynamic simulation and then reviewing the detailed results within VistaPro.
Hot Aisle / Cold Aisle Modelling
Do hot aisle / cold aisle arrangements require special features in IESVE?
No. These configurations can be modelled using standard IESVE functionality. ModelIT is used to effectively zone the aisle geometry within the datahall. ApacheHVAC is then used to control airflow paths, containment strategies, and recirculation without requiring any bespoke tools.
Can leakage or recirculation between hot and cold aisles be represented?
Yes. ApacheHVAC allows users to specify controlled recirculation flows, enabling realistic assessment of containment effectiveness and the impact to cooling performance and fan energy. CFD can be layered on top of this as a complimentary analysis to validate stratification and recirculation risk.
What’s the best way to model data halls that have very high temperature differences (e.g. 90°F cold aisle, 120°F hot aisle)?
These scenarios typically require custom ApacheHVAC networks, with airflow rates defined manually. The temperature delta will be a function of the server load and the volume airflow through the rack. Once appropriate airflows are set, the system sizing tools can be used to size coils, fans, and chillers.
Can you explain how you model servers within IESVE in more detail?
Within IESVE, you split the data hall into key zones to reflect the server racks and the containment strategy such as the hot and cold aisles. Convective heat gains are applied to the server rack to represent IT loads and the associated heat gain. The ApacheHVAC module is used to control the air flow path through the data hall.
HVAC Systems & Energy Modelling
What’s the difference between load calculations with and without HVAC systems?
Peak loads and energy use can vary significantly depending on system configuration.
Can pressure drops, pipe sizing, or pump selection be calculated?
IESVE will:
However, the VE is not a detailed hydraulic sizing tool. Flow rates and design airflows can be exported for use in specialist duct and pipe sizing software.
Performance Metrics, Compliance & Optimisation
Does IESVE explicitly calculate PUE and WUE?
The VE does not output a single PUE value automatically but has the functionality to setup and model a simulation that can provide all the constituent loads (IT, cooling, facility) required to calculate an annualised PUE. This extends into running multiple simulations, considering the available inputs, to assess the range of potential PUE performance the data centre could operationally experience when in use.
Which data centre use cases benefit most from dynamic simulation?
Attendees highlighted several high‑value applications, including:
Dynamic simulation allows these assessments to be undertaken consistently within a single model.
Can IESVE support regulatory compliance for data centres?
Yes. Some regulations require a simplified approach, however, IESVE can support compliance for frameworks such as:
It is important to note compliance models are designed to demonstrate regulation adherence, not necessarily to predict real‑world energy use. The VE’s strength around applying analysis through a single model is again exemplified.
Can IESVE account for data centre embodied carbon estimation?
Embodied carbon assessments are performed externally via integration with One Click LCA. Users can export VE model data directly into One Click LCA for full embodied carbon analysis.
Training, Support & What’s Next
Is there dedicated data centre training available?
While there is currently no generic off‑the‑shelf training course for data centre modelling, IES Consulting provides tailored project mentoring and support, helping teams apply IESVE effectively to real‑world data centre challenges. The consultancy team offer strategic services across the planning, design and operational stages of a data centre life-cycle for both new and retrofit solutions. Do not hesitate to contact our team for more information by emailing consulting@iesve.com.
Are more advanced data centre features coming?
IES is actively developing and expanding its data centre modelling capabilities, including more explicit representations of liquid cooling, hybrid systems, and evolving infrastructure typologies.
Want to learn more?
If you’re exploring AI‑ready, high‑density, or retrofit data centre projects, dynamic simulation can provide the insight needed to balance performance, resilience, and efficiency—both now and into the future.
Watch the webinar on demand or contact our team to discuss your project requirements.
