Coil Cleaning
An
air conditioning system has two coils, usually made of copper tubes with
aluminum fins. The evaporator coil, or indoor coil, is often described
as the "cold" coil because it provides indoor cooling. The coil works
by absorbing heat from the indoor air that is blown over by the air
handler's
fan. The condenser coil or outdoor coil is the "warm" coil as it rejects
the heat as a fan blows outside air over the surface.
Coils - they're everywhere
Coils are found in refrigeration equipment
including those used in supermarkets and restaurants. It is not uncommon
to find hundreds of "through-the-wall" fan coil units in a hotel,
dormitory or apartment building. As the air moving over the coils contains
dust, dirt, pollen, moisture and other contaminants, the coils get dirty
and become less efficient.
In addition, the evaporator coil and its condensate pan can become fouled
with pollen, mold spores and other biocontaminants that can have adverse
effects on indoor air quality. If not maintained, the moisture around
the evaporator coil can become a breeding ground for bacteria and mold.
Dirty Coils Waste Energy and Cost Money
A coil fouled with dirt and grime cannot supply proper heat transfer
and results in greater energy consumption. Equipment operating with
dirty coils can use up to 37% more energy than those with clean coils.
Additionally, a dirty system’s cooling capacity can be reduced by as much as 30%. Dirty
coils increase operating pressure and temperatures that breakdown the
compressor’s lubricant and can result in equipment failure. A failed
compressor means no cooling and costly repair.
Coil Cleaning Frequency
A coil cleaning program should be instituted when the coils are new,
clean, and should be performed with a frequency to prevent deterioration
of the coils. This can be as often as four times a year (monthly cleaning
is reported in some areas).
If they do not already exist, install easy to open panels to gain access
to the coils. This will make the job much easier and consequently, the
more likely to be done when coil cleaning is necessary.
How to Clean Coils
If the coil is contaminated with a light dust or dirt not adhered to
the fins, blowing low pressure compressed air across the fins or the
use of a soft bristle brush may be sufficient. Applying
a plain water or mild detergent solution to the surface, allowing it
to sit for a short time then rinsing is employed in some cases. More
aggressive deposits call for the use of stronger cleaning solutions or
solvents as required.
Coils can be steam cleaned but require extra care. Steam
must be applied at low pressure and the stream kept parallel to the fins
to prevent folding the fins over.
Another popular coil cleaning method employs the use of a garden-type
pump sprayer to apply foaming chemical to the coil surfaces. The
foam is allowed to dwell on the surface to saturate the fins. The
foam is then vacuumed up and the process repeated. Finally, the coil
is rinsed with clean water from a hose.
Perhaps the most popular cleaning method used in recent years is using
pressure washers to clean coils. Pressure cleaning coils
may increase airborne Macromolecular Organic Dust (MOD) which must be
contained to the area being cleaned. Pressure cleaning should be
done in the opposite direction of air flow through the coil. A
cleaning solution can be applied before the pressure rinse using the
built in chemical injection system on the pressure washer or a hand sprayer. Care
must be taken when using a pressure washer to avoid damaging the fins
on the tubes. Water
leaving the coil should be free of particulate. If it is not, repeat
the process.
Recently, Goodway introduced its line of CoilPro™ coil cleaning
machines. The Model CC-140 is
a self contained two-wheeled cart with its own built in water and chemical
tanks that can operate on building power or an integrated rechargeable
battery. It can carry 5 gallons
of water or can be connected to the building water supply for continuous
operation. It supplies a water stream at up to 140 PSI at 1 GPM
by means of one of four available spray nozzles. The on-board battery
and water/chemical tanks allow for use anywhere. Additional models
include the CC-600 AC powered unit which delivers up to 600 PSI at 1.6
GPM for thicker coils and the CC-100
backpack coil cleaner unit for extreme
portability. These
products have been enthusiastically received by maintenance professionals
and they represent the first true real break-through developments in
coil cleaning in a long time.
Coil Cleaning Chemicals
There are many acid and alkaline based cleaners available to clean coils. These
chemicals clean by creating a chemical reaction between the cleaner and
the metal that harms the surface of the metal. This
damages the coils by causing metal loss over time. Acid and alkaline
based chemicals carry with them an inherent danger to personnel and equipment.
The foaming properties of many coil cleaning formulations is important
to help float debris our of the coil body where it can be rinsed away.
While some chemicals are advertised as “no rinse”, many
believe that all cleaning chemicals should be thoroughly rinsed from
the surface to prevent coil damage.
To clean coils, Goodway offers CoilShine™, a biodegradable, expanding
foam detergent specifically formulated for use with the CoilPro™. This
is a non-acidic, non-fuming solution that can be safely washed down drains. CoilShine-BC
is a commercial grade, ready-to-use mold inhibitor for HVAC systems that
helps prevent the growth of odor, stain and damage causing organisms
such as mold, mildew and fungi.
Don’t Forget the Condensate Pan
The air drawn across a cooling coil contains water vapor which condenses
and collects in a pan under the coil called a condensate pan. The
pan is connected to a drain line to keep the pan from overflowing and
causing damage to the air handler or other building structures. As
it is generally wet, microorganisms can form colonies in the condensate
pan. Cleaning the condensate pan and checking for proper
drainage is an important part of the coil cleaning process.
To help prevent growth of these organisms, the pan should be treated
between cleanings with a biocide. Goodway’s PanCare is one
example. PanCare is formulated to prevent the build-up of slime
and harmful bacteria in condensate pans. It kills 99% of Legionella
Pheumophilia and Salmonella Typhii Bacteria. It also contains
a ruse inhibitor and an acid rain neutralizer and will work for up to
3 months on a 3 to 5 ton system.
What our Customers Say
Anthony Rizzica, Senior Engineer at Yeshiva University’s In New
York, NY
When asked about the performance of the CoilPro,
"We actually cleaned
the coils so well that we gained almost 50 to 60 tons worth of cooling last
summer and saved around $75,000.00 to $80,000.00.
If I had to put a return on investment on it, I would say for every 25
to 50 coils that we clean, the machine pays for itself".
When asked what other savings does Anthony see using the CoilPro,
"Well
man-hours are a saving
- it only takes one man to operate. It's convenient. What used to take
us a week, we now do in two or three days."
When asked to compare the CoilPro to conventional pressure washers,
"It’s more portable, it’s definitely lighter in weight. I
like the tanks that hold the chemical and water – there’s no hose involved.
The battery pack is a great saver, too. We don’t have to worry about cords
being plugged in, people tripping, hazards and all. Safety is always
a concern around here."
View
Goodway's Coil Cleaners
Goodway Technologies Corporation
Goodway Technologies Corporation was founded in 1966 by Per K. Reichborn.
Since its earliest days, the company has built a reputation for manufacturing
the highest quality cleaning systems in the world. "This commitment"
says Reichborn, "not only extends to our manufacturing, but to everything
we do, every day, for every product and service. Achieving this high
quality of performance is the shared responsibility of each employee
in every department."
Today, Goodway cleaning machines span the globe.
From Afghanistan to Zimbabwe, Goodway equipment is used in over 125 countries
and on every continent, including Antarctica.
To view a complete line of Goodway cleaning machines
or to receive more information about a Goodway cleaning machine or to
purchase a Goodway cleaning machine please visit Goodway.com
or contact Goodway Technologies Corporation at 1 800 333-7467.
