The
Future Is In Plastics
A development in cooling tower construction can
ease installation and maintenance demands.
By Brian Kraemer
Anyone who has ever walked into an office building
during the dog days of summer to find out that the
air conditioning system doesn’t work knows how
hard it can be to accomplish anything. It’s
taken for granted that even though it’s scorching
outside, the office will be pleasantly cool. Of course,
the average employee doesn’t realize how many
different systems and components have to be in good
working condition to lower the temperature to a blissful
68°F.
A facility manager, on the other hand, makes a living
keeping the air conditioning unit and other building
necessities operating smoothly. In particular, the
cooling tower plays a pivotal role in employee happiness;
if it isn’t functioning properly, the air conditioning
isn’t working, and if the air conditioning isn’t
working, you better believe a facility manager is
going to be inundated with phone calls, pages, and
smoke signals letting him or her know.
Like any technology, cooling towers have advanced
over the years. From a humble, organic beginning in
wood, sheet metal has become the predominate palette
for cooling towers, which is a logical advancement.
Unfortunately, metal towers, like wood before, have
their limitations.
“Obviously sheet metal is going to rust,”
says John Flaherty, president of Rockaway, NJ-based
Delta Cooling Towers, Inc. The amount of water that
is run through a tower on a daily basis will take
its toll on the material, just like weathering would
on any other metallic object.
“In order to prevent rusting, the metal towers
are coated with a galvanizing, which is a zinc coating
that doesn’t stop corrosion; it just slows it
down,” Flaherty explains. “Eventually,
the bare metal is going to be exposed, and that will
corrode.” So now chemicals get added to the
equation, making the life of a facility manager more
difficult.
“It’s like a swimming pool in these
towers. The water has to be maintained or else algae
will accumulate. But the chemicals that prevent the
algae attack the metals and cause premature corrosion,”
says Flaherty.
But like their wooden predecessors before, sheet
metal towers will eventually be replaced with something
more reliable. In this case, it’s plastic.
“Like a lot of outdoor equipment, plastics
are making inroads. Cooling towers, in particular,
have only recently become a more viable option for
a large industrial, commercial, or health care applications,”
says Flaherty.
That is not to say that plastic cooling towers haven’t
existed before. But they have been smaller and intended
to be used on buildings with less square footage and
have a lower cooling load that needs to be accommodated.
Because of advancements in molding technology, the
path is clear for plastics to become a major player
in the cooling tower universe. “We can mold
pieces as large as 20' long and very wide,”
says Flaherty. Towers of this size should be big enough
to handle any load that a building is going to throw
at it.
The real advantages of plastic towers are actualized
in two ways. First, the plastic isn’t going
to corrode. This allows a facility manager to use
all the necessary chemicals in the tower without having
to worry about how many days are left before a giant
hole appears on the side.
“We use a high density polyethylene for the
specific reason that it isn’t going to corrode
and break down through regular use,” Flaherty
continues. “The plastic is formed with large
molding equipment. We melt plastic resin over a mold
to form a skin. Then, they pop the mold apart and
get a piece which will make up the entire casing of
the tower.”
Manufacturing after the casing comes out of molding
includes incorporating heat-transfer media inside
the casing, plumbing the water distribution system,
and the mechanical fan motor assembly which draws
air through the unit.
Installation is so easy it’s criminal. For
example, in a large application, the sump and the
main housing are shipped to the building, and the
main housing is fit into tongue and groove fashioned
sump posts; water and electricity are hooked up to
the cooling tower, and it is fully operational.
“Once the tower is put together, a facility
manager can be sure the structural elements will remain
fit—the plastic won’t wear out or allow
for leaks to form,” Flaherty explains.
This sense of security alleviates the other looming
issue with cooling towers: downtime. If the cooling
tower goes down, the entire building will usually
shut down as well, which can result in lost money.
By the same token, because installation is not complex
and doesn’t require on site construction, the
install or retrofit can be arranged in an evening
or over a weekend when the building is not in use.
This allows employees to continue coming to work and
avoids interruptions in the work place.
Plastics are emerging as the next trend in cooling
tower technology because of their plug and play capabilities.
A facility manager can install the tower in an evening
or in one day over the weekend, hook it up to the
HVAC system, put the proper chemicals in to treat
the water, and not need to worry about waking up one
day to find a hole in the side of the tower and, have
the building shut down.
Information for this article was obtained from an
interview with Flaherty and with information from
the Delta Cooling Towers Web site. For more information,
visit www.deltacooling.com.
Have plastics recently gained a larger
and more prominent role in your facility? E-mail your
questions or comments tobkraemer@groupc.com.
