Feature
PREVENTATIVE MAINTENANCE
OF HVAC&R EQUIPMENT
By Richard Fennelly, Chief Operating Officer, CoilPod
Millions of plug-in cooling appliances are in commercial operation
worldwide in all sorts of retail food outlets and institutional settings.
Clearly, there are multiple advantages for any preventative
maintenance programme that includes the cleaning of such
condenser coils. Despite this reality, most owners of such units
do not do such cleanings on a regular basis. One experienced
service provider to the commercial refrigeration market
has stated that he believed that at least 80% of the units
in operation are never regularly cleaned. We think that the
percentage may be even higher, well into the 90’s. One possible
reason for this neglect is the practice of hiding the condenser
coils for these units behind a decorative panel or grille. It is
an “out-of-sight, out-of-mind” phenomenon as a result --- a
serious problem that has largely lain unnoticed even by HVACR
cooling experts. They are chasing more attractive things than
labour intensive coil cleaning.
The Carbon Trust did a study in 2018 and estimated that, on
the basis of the reported literature, there was an energy savings
www.hvacronline.co.za
S
uch units include kitchen appliances, refrigerated
display merchandisers, ice machines, and the like. The
manufacturers of these appliances uniformly recommend that
the condenser coils be cleaned frequently, depending upon the
location and type of traffic adjacent the cooling unit. The Food
Service Technology Center (FSTC) of San Ramon, California
counsels that such coils should be cleaned at least once each
calendar quarter.
Dirty condenser coils kill the efficiency of the unit’s
refrigeration functioning and are the biggest single reason
for non-scheduled service calls, according to FSTC. Dirty coils
ultimately can be a prime reason for expensive compressor
replacement or new unit purchase when the overburdened
unit begins to malfunction. All of these are expensive results
of a failure to include condenser coil cleaning in a disciplined
preventative maintenance programme. Clean coils ensure
that the appliance runs more efficiently with the following
important benefits:
1. a major savings of electricity in their operation;
2. a reduction in the amount of unanticipated service
calls; and
3. a prolongation in the life of the appliance unit.
of about 20% for the better cleaning and servicing of any type of
currently deployed HVAC&R cooling item, either air conditioning
or refrigeration. They did recognise wide variations in savings
seen for individual units, but as more and more units are coil
cleaned and given related servicing, this 20% value would be
approached. Earlier, an actual field survey of ten commercial
reach-in fridges and freezers largely confirmed their conclusion
showing a 17% energy savings from doing condenser coil
cleaning. Interestingly, four of the units were badly fouled, which
might be a common condition in most locations. These units
showed as average electric waste from these clogged coils of
about 3 500 KwH/unit/year. When cleaned, the energy savings
averaged 47%.
Based on these data we have an internal guesstimate that the
average commercial refrigeration unit of the reach-in type might
be wasting about 1250 KwH/year.
So how to clean the coils? Brushing and vacuuming of the
surface of the condenser coil structure will result in some benefit
since it will largely remove the surface contaminants on the coil
structure. However, a stream of compressed air is often needed
to remove dirt and other debris embedded within the coils.
Unfortunately, if compressed air is used in any type of indoor
setting, it needs to be captured to avoid badly polluting the
surrounding area adjacent the cooling appliance/s. The capture
RACA Journal I May 2020
Coil cleaning
is an aspect
that has
been ignored
by industry.
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