ASHRAE Journal - August 2020 - 24

INDUSTRY 4.0

remote workforce, have resulted in enormous spikes in
use for some software applications.
Having the ability to model these infrastructure utilization scenarios in advance using digital twins has a
direct impact on capital efficiency for software deployments and their subsequent resiliency in operation.

IT vs. Infrastructure Utilization, Capacity Management
And Optimization Use Case
Fundamental issues for data center operators often
include the following questions: How much overprovisioning is occurring as part of the current design
strategy? How much capacity is underused due to a limitation in one or more parts of the infrastructure (i.e.,
constraints on the cooling capacity, airflow management
or power distribution)? These capacity questions are
not easy to answer based on nameplate information or
analysis of design drawings. Using digital twins can help
with the answers.
Data center designs are often one-for-one approaches
where cooling provisioned is matched to power delivered. On paper, this approach seems acceptable, but it
gives little to no consideration that both energy vectors
cannot be evenly distributed across the entire data center footprint due to a variety of limiting factors.
Since the infrastructure and equipment variations that
impose these limits can be infinite and largely unknown
(e.g., details of the IT deployment), it's not practical to
design in advance for infinite flexibility. This inevitably
leads to constrained resources, lack of efficient utilization, and stranded capacity.
For colocation data centers, service level agreements
(SLAs) of various tenants can lead to further stranded
capacity. Day-one designs often have limitations or design
assumptions for acceptable (and allowable) inlet conditions per the ASHRAE thermal guidelines. If those conditions change as the result of SLA requirements of a new
tenant, the by-product can be constrained cooling capacity (either at an airflow or cooling capacity level or both).
Being able to answer these executive questions rapidly and concisely directly affects a business' ability to
quickly respond to evolutionary changes to the IT within
a data center. Digital twins offer the ability to simulate
many parameters of these questions and quickly identify
viable options.
Those options can then be analyzed to determine an
optimized strategy to reduce capital costs and improve
24

ASHRAE JOURNAL

ashrae.org

AU G UST 2020

rapid deployment of the software solutions.

Energy-Efficiency Improvements
Digital twins also offer an opportunity to calibrate and
verify building automation system (BAS) operation as
part of both a pre- and post-installation commissioning
process. Many data center designs are constructed using
a common deployment strategy or prototypical basis. As
such, optimizing that first installation through a combination of calibrating installed systems and a "what
if" digital twin analysis on system modifications can
identify real-world savings with subsequent data center
builds.
A useful example may be: A data center wants to
determine the maximum number of economizer hours
available for a given location based on a combination of
allowable entering air conditions per ASHRAE thermal
guidelines and x-factor for airborne contamination
risks.
In the traditional model, this scenario would be modeled using various tools like MS Excel, computational
fluid dynamics (CFD) and related energy modeling
tools. Fundamentally, results from those tools are heavily dependent upon gross assumptions for the IT equipment and their associated performance. As a result,
these assumptions will often vary widely from realworld conditions.
Conversely, a calibrated digital twin enables realworld modeling of the actual IT conditions and operational parameters. The yield is an optimized design
supported by accurate operational decisions for the next
generation of that data center. These differences can be
monetized and generate significant capital and operational cost savings.

Operational Management Improvements
Digital twins offer additional abilities in operational
management improvements beyond the typical functionality of BAS or data center infrastructure management (DCIM). Specifically, digital twins incorporate an
element of predictive modeling and analysis that can't
be replicated within other software solutions.
An additional level of functionality comes from the
digital twin's ability to create a virtual environment
that can be shared with remote teams without needing
on-site attendance. This feature has become a particularly interesting benefit in 2020 when site access for all

https://www.ashrae.org/

ASHRAE Journal - August 2020

Table of Contents for the Digital Edition of ASHRAE Journal - August 2020