Technical information

0115 900 5858
www.diversitech-uk.com
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REPRI NTE D WITH PE RMISSION FROM ACR TODAY
Clean coils equals efficient
Tom Fitzsimons, product manager with cleaning product manufacturer DiversiTech points out
the tangible benefits of keeping coils clean.
18 JANUARY 2010 ACR TODAY
PROMOTION
A regular cleaning and maintenance programme
is essential for the efficient running and cost
effective operation of air conditioning equipment
and will provide improved indoor air quality (IAQ)
and over the lifespan of the equipment, saving the
owner money.
Cleaning the coils, especially on outdoor units
achieves several important objectives.
1) It improves the heat transfer efficiency between
the refrigerant inside the coil and the ambient air
outside. The more efficient the heat transfer, the
more effectively the cooling system can operate.
Dirt and grime that have gathered on the coils over
time will inhibit heat transfer and increase the
burden on the compressor causing more frequent
operation with increased strain on the internal
components which may shorten its lifespan and
incur repair or premature replacement costs.
2) There is a significant impact on the equipment
running costs when coils are heavily contaminated
and even a small amount of dirt can have a
marked effect on energy usage. Tests have
demonstrated that a 1.52mm layer of dirt can
increase energy consumption by over 50%. Over
time, the extra operational cost is likely to be
significantly higher than the cost of applying a
regular cleaning regime.
3) A major advantage in cleaning and maintaining
the evaporator coil is the improvement in the
environment inside the building. Indoor air quality
(IAQ) can be compromised by the circulation
through the evaporator of potentially harmful
bacteria. Poor IAQ can be a contributory factor to
sick building syndrome (SBS) or Building Related
Illness (BRI) and potentially have negative effects
on a business, including a loss of customers,
reduced employee productivity and possibly
liability issues.
Which Cleaner?
Product selection when maintaining coils is so
important. The engineer should always opt for a
coil cleaner which has been designed to remove soil
and contaminants from the specific equipment to
be cleaned. Coil cleaners work by breaking down
dirt, dust and mould, emulsifying oil and grease and
dissolving mineral deposits
However using traditional acid or alkaline based
foaming cleaners can have a detrimental effect on
the aluminium fins on the coils. This is because
while traditional acid cleaners leave coils shiny and
bright, what in fact has happened is that the cleaner
has reacted with the aluminium and the subsequent
foaming action of the cleaner strips away the surface
layer of aluminium from the coil. Less metal on the
coil means that heat exchange is less effective and so
more energy is required to achieve the same level of
cooling and of course the life expectancy of the coil
is reduced.
Research has showed that after five cleans by an
acid based cleaner, as much as 24% of the metal
from the fins has been eaten away. Typical alkaline
cleaners, although more effective at breaking down
organic dirt than acid based cleaners, still remove up
to 18% of the fin material.
DiversiTech has developed Pro-Universal™ a
multi-purpose coil cleaner which cleans indoor
and outdoor coils very effectively but also has no
detrimental effect on the aluminium fins. Pro-
Universal™ is designed to attack dirt and grime but
not the coil and although alkaline based, it contains
a special inhibitor that prevents the chemical from
attacking the coil.
Easy on the hands
The graph below shows the detrimental effect that
a build up of dirt on the surface of coils will have
on the energy consumed by the air conditioning
equipment. Dirty coils are expensive to run. Pro-
Universal is so-named due its versatility because it is
suitable for use on both condenser and evaporator
coils alike. This reduces the need for the engineer
to carry around an array of cleaning products for
different applications.
Pro-Universal™ is available in a 5 litre
concentrated version, a 1 litre Good to Go (G2G™)
pre-mixed version and also a unique dry “granular”
version offering great advantages when it come to
transport and storage and excellent user benefits
including ease of use and excellent performance.
DiversiTech® recommends that coils should be
cleaned a minimum of twice per year. However,
this frequency should be increased depending
on the hours of operation and the internal and
external environment.
18 Internal.indd 18 18/12/09 09:56:41