Building Operating Management September 2011 - FacilitiesNet

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SEPTEMBER 2011 101
While it’s certainly possible to replace
one particular piece of an HVAC
system and not touch the rest for 10
years, it’s not likely. When considering
upgrading one piece, take a look at everything
else, as well.
“You wouldn’t want to replace one
piece and not consider the other pieces,”
Ulrich says. “If you have a chiller
that’s reaching the end of its useful life,
you have to consider the condition of
the cooling tower. It’s a mistake to replace
the component of a system that
has an obvious problem and not have
the foresight to take a holistic look at it
and say, ‘the chiller’s 30 years old and it
has a problem, what else is that old?’”
One good place to start when looking
for other areas that might be affected
by an upgrade is the control
system. If you have a legacy control
system, you’re running the risk of either
limiting your upgrade options or
not getting the most out of them.
“I wouldn’t limit myself with an old
BAS or energy management system and
have that tail wag the dog, if you will,”
Don’t just
assume that a
new piece will fit
in the right spot
— or be the right
weight if it’s a
rooftop unit
Bamonte says. “I wouldn’t say, ‘since the
controls can’t handle certain types of
equipment, let’s not go down that road.’
I would start with the main equipment
and then work from there.”
Other things to consider have more
to do with the building’s infrastructure
than anything else, such as ductwork
and piping. And, Bamonte points out,
don’t just assume that a new piece will
fit in its intended spot — or be the
right weight to be supported if it’s a
rooftop unit.
Codes play a part as well. With
HVAC components having such long
lifespans, codes can change multiple
times from the time an HVAC product
is installed until the time it is replaced.
“Say I’ve got an A/C unit in the
middle of a 20,000-square-foot floor,”
says John Fallon, vice president of service
for Donnelly Mechanical. “I want
to change it, but now the code says I
have to have fresh air going to it. It’s in
the middle of a floor. How am I going
to get fresh air to it?”
There’s one other consideration before
diving into upgrades, says Fallon.
“If you’re going to be there five
years or longer, then I would be looking
at upgrading,” he says. Less than
that, and stretching a system’s lifespan
while repairing when needed becomes
a more attractive option.
The Human Element
Regardless of how many parts of an
HVAC system you’re going to replace,
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