ASHRAE Journal - April 2021 - 21

COLUMN SOLVING PROBLEMS

their BAS systems. The communication wiring used in a
network operating on a proprietary protocol will likely not
be the recommended gauge for the higher speed communications used by modern BACnet networks. This requires
a total rewire when replacing controllers, " he said.
Kilcoyne says other aspects to note during ﬁeld investigations are the quality of installation in each control
panel, proper labelling and termination of all signal
wires and proper communication cable shielding splices
and grounding.
" Issues with cable shielding is the most common reason
for 'network noise' and losses in communication, " he said.
BAS network diagnostic software can be a powerful
tool. Most manufacturers provide some form of diagnostic or commissioning programs as part of the main BAS
network hosting software package, he said. These tools
can test several aspects: communication speeds of each
subnetwork, report ﬁrmware versions and point loading of individual controllers and test for proper airﬂow
modulation of variable air volume (VAV) boxes, among
other information.
" If these programs are not already present, there is also
third-party software designed to perform these functions, " said Kilcoyne. " Some are free but require signiﬁcant training to learn and interpret results. Others are
paid and can provide intuitive reports that can quickly
diagnose controllers, networks or conﬁguration settings
that are causing system issues. "

Preventing Issues from Recurring
Use Your Resources

Kilcoyne recommends that anyone looking to help prevent issues in BAS design start with ASHRAE Guideline
13-2015, Specifying Building Automation Systems.
Kilcoyne said the Guideline includes a full sample
guide speciﬁcation for control systems, which is helpful.
" It will explain in detail in layman's terms what exactly
all those requirements mean and why you do it, " he said.
Del Monaco said Guideline 13-2015 is especially helpful for beginners in the industry. One challenge the
Guideline can help with is when designers and engineering ﬁrms rely heavily on their BAS vendors and do
not take the time to learn about the system in-depth,
he said. Guideline 13-2015 helps engineers understand a system's controllers, devices, etc., and how
those integrate into the system architecture, said Del
Monaco.

" The Guideline 13 committee is working on a reference
guide (three to ﬁve pages) that designers can use as a tool
to communicate with owner to understand BAS and how
they might want to set their system up, " he said.
Kilcoyne agrees that the guidelines are " extremely
valuable " for control engineers working with building
owners and clients.
" What really helps is when you bring [Guideline
13-2015] up to a client or a controls vendor, there's not
much better room for discussion when they say we think
we've got a better way to do it, " he said. " We say, 'We
defer back to ASHRAE's work in [the Guideline].' "
In addition to ASHRAE Guidelines 13 and 36, three
ASHRAE Handbook chapters, Chapter 7, " Fundamentals
of Control " in the 2017 ASHRAE Handbook-Fundamentals;
Chapter 11, " Refrigerant Control Devices " in the 2018
ASHRAE Handbook-Refrigeration; and Chapter 48, " Design
and Application of Controls " in the 2019 ASHRAE Handbook-
HVAC Applications are commonly referenced resources.
Del Monaco also points to ASHRAE e-Learning and
technical seminars from previous ASHRAE conferences
as more resources.
Del Monaco also recommends researching the individual
BAS products and talking with the facilities team and operators to understand their preferences and pain points.
" They live with these systems and buildings on a daily
basis and have a wealth of knowledge. It's in all of our
best interest to work together so the building meets the
needs of the owner and the building occupants, " he said.
Benson recommends working closely with the owner,
O&M teams and commissioning authorities. " This is your
best path to tap into institutional knowledge, receive
feedback, and ensure decisions meet your intent, " he said.
" It isn't easy, but you're not going to leverage that talent
without real and open conversations. "
In addition, engineers should become familiar with
the speciﬁc requirements of the BAS platform they are
designing, said Kilcoyne.
" Each one has small variations in their network architectures that can become important in specifying a system for issue-free operation, " he said.

Keep in Communication
Once the design work is over, the project is ongoing. Pay
attention to the commissioning process, said Benson.
" This feedback will tell you where things were misunderstood or difﬁcult to get working, " he said.
APRI L 2021

ashrae.org

ASHRAE JOURNAL

http://www.ashrae.org

ASHRAE Journal - April 2021

Table of Contents for the Digital Edition of ASHRAE Journal - April 2021