By Richard P. Fennelly
It’s a well-known industry fact that refrigeration and freezer appliances, which are no longer exclusive to supermarkets, are major electricity “hogs” in retail stores.
Unfortunately, many store owners/operators are not following an important maintenance task that is uniformly recommended by the manufacturers of these appliances: monthly or bimonthly cleaning of the condenser coil unit that is contained in the appliances. It is a topic that needs to be front and center for any organization interested in maximum efficiency for these appliances.
The need for such a cleaning protocol largely goes unrecognized because the visually non-appealing condenser coil unit lies hidden behind a panel or grille blocking view of its deteriorating condition over time.
The problem festers until a service technician discovers it on an expensive unscheduled service call when the unit begins to malfunction. With the projected market in refrigerated display cases alone slated to grow from about $8.8 billion dollars in 2012 to about $16.3 billion dollars in 2019, this issue is likely to grow exponentially, especially for plug-in units which might account for almost 68% of this growth.
Since the condenser coils are responsible for dumping the warm air extracted from the enclosed cooling chamber into the outside air, the build-up of dirt or debris on the coils will compromises their heat transfer ability and the cooling efficiency of the unit. And over time, such dirt and debris invariably does form on the coils unless a regular maintenance program is followed. The result: close to a 10% higher electricity bill for each refrigeration unit and close to a 20% higher bill for each freezer unit!
Additionally, the non-maintained units work harder, causing premature appliance aging due to longer run times, and have an increased chance of equipment failure because of higher pressures and operating temperatures. Finally, the store environment becomes less “green” as the coils collect dirt and other debris.
The benefits that come with a condenser coil unit cleaning program are reflected with 75% of those issues deemed most important by the attendees of the recent Star Refrigeration 2013 Roadshow, namely, energy savings/run efficiency (26%); operating cost (18%); reliability (14%); maintenance (14%); and performance (3%). (For survey, go to http://www.starrs2013.com/star-refrigeration-roadshow-2013-survey.aspx .)
What is the best way for the maintenance program to be conducted? Since the plug-in appliances containing these condenser units are located inside the store, the traditional cleaning method has been to use either a combination of brushing and vacuum or, even better, a combination of brushing, vacuum, with a supply of compressed air to assist in the dislodging of dirt or debris that is lodged within the coil structure.
Using compressed air (e.g., from a standard wet/dry vac) is problematic since, unless contained, this air steam will pollute the store environment necessitation additional cleanup. The traditional way in which dislodged debris has been captured has been the use of a container, such as a box, lined with a damp cloth to capture and hold the airborne debris. Often, a two person team was needed for the cleaning operation – one to hold the box/cloth capture device, the other to blow compressed air and vacuum during the cleaning operation.
Most recently, however, more scientifically engineered dust containment bags have been developed that allow for a single person to effectively blow out debris from the coils while vacuuming the airborne debris into a vacuum appliance without polluting the surrounding environment. In many cases, it is not even necessary to have this rather non-technical cleaning task performed by a refrigeration service technician — it is definitely within the capability of the do-it-yourselfer.
Preventative maintenance programs are often the first ones to be eliminated when operating budgets are reduced. This is shortsighted since a well-structured preventative maintenance program for these refrigeration and freezer energy “hogs” can more than pay for itself in energy savings while prolonging the life of such equipment and reducing the cost of maintaining it over its lifetime. It is easy to save from $100-$200 per unit in electric costs as a result of a disciplined condenser coil cleaning program. For stores that contain a multiple of such units, the savings can be in the thousands of dollars. These cost savings go directly to the bottom line.
There has been much talk and press attention given to a whole host of energy efficiency steps that the retail industry can take (energy efficient lighting, better insulation, better protocols for heating and cooling schedules, etc.). These all constitute “low hanging” fruit, most of which by this time has been picked. So how might we continue to squeeze out more efficiencies? Certainly, the scant attention that appears to have been paid to a disciplined PM program for the condenser coils in plug-in cooling appliances needs to change.
Richard P. Fennelly is director of product development at Coilpold.com, manufacturer of the Coilpold dust containment bag for use in the condenser coil cleaning of commercial refrigeration and freezer appliances (firstname.lastname@example.org).