An Oft-Ignored Energy Savings Practice: Refrigerator/Freezer Coil Cleaning

Concerns over climate change are sparking renewed interest in all sorts of strategies to reduce the generation of greenhouse gases thought to be largely responsible for the situation we may now be facing. Energy efficiency in regard to existing power generation technologies is just one of the components being discussed. Our nominee, which is certainly not in the forefront of discussions that we have seen, appears to constitute “high-hanging” and as yet unpicked fruit on the energy efficiency tree…

Plug-in refrigeration and freezer appliances of many differing types are in a wide variety of commercial and industrial settings, not to mention being in residential locations as well. They are major energy “hogs”, consuming significant amounts of electricity even if properly maintained.  Unfortunately, most owners/operators of these units do not follow a critical maintenance task: frequent cleaning of their condenser coils. The recommended frequency of cleaning is at least four times per year (and more frequently in environments leading to more severe coil fouling than the norm). The result: a significantly higher electricity bill for each non-cleaned unit as well as increased service calls for malfunctioning units and, sometimes, unit replacement due to compressor failure when the unit suddenly malfunctions.

In February 2015, the Food Service Technology Center (San Ramon, CA, USA) presented data showing how costly non-cleaned units can be to the owner:

Double Door Merchandiser
(6 years old):

Dirty: $1325/year/unit
Clean: $700/year/unit
Savings: 47% = $625/year/unit

Larger Double Door Fridge:
Dirty: 24 kwh/day/unit =
$950 /year/unit
Clean: 13 kwh/day/unit =
Savings: 46% = $433/year/unit

Milea February 2019 728×90

Single Door Freezer:
Dirty: $546/year/unit
Clean: $289 /year/unit
Savings: 47% = $257/year/unit

Double Glass Door Fridge:
Dirty: $439/year/unit
Clean: $219/year/unit
Savings: 50% = $220/year/unit

Our takeaway from the above data: not cleaning these coils can roughly double the electric needed to run these refrigeration units; coil cleaning can cut the electric bill roughly in half.

One might expect that owners of such plug-in cooling appliances would regularly clean the condenser coils in these appliances.  Sadly, they very often do not. Non-attention to this important cleaning task may occur because the visually non-appealing coils lie hidden behind a panel or grille.  It appears to be “out of sight, out of mind” for most owners of such appliances.  Any unacceptable buildup of dirt and debris is often not noticed until a service technician discovers it when responding to an unscheduled service call when the unit begins to malfunction.

We have conducted preliminary analysis on the likely energy waste in the USA (our home country) in just the commercial refrigeration sector. Our conclusion is that it could approach $US 10.8 billion yearly.

These plug-in appliances are often located in indoor environments. One cleaning method has been to use either a combination of brushing and vacuuming.  Often, debris remains imbedded within the coil structure even after this type of cleaning is performed.  A blast of compressed air will quickly and efficiently dislodge debris from deep within the coil structure, but the debris blown off by a blast of compressed air, unless contained, will pollute the surrounding area necessitating additional time consuming cleanup.

To remedy this collateral contamination issue, condenser coil cleaning with compressed air has traditionally involved directing it through the coil structure towards a dust capture item, such as a damp cloth, located on the other side of the coils. Often, the cloth blew off the unit during the cleaning operation causing a mess in the surrounding area.  Even if it stayed in place, it became debris-encrusted, needing disposal or possible cleaning at some point, particularly if multiple coil units need cleaning at a given location. In this day and age, the “damp towel” capture method appears in need of retirement.

Only recently, there have been some developments to create better dust containment mechanisms to replace the traditional damp cloth capture item.  These approaches utilize engineered products that more effectively seal the coil unit structure during compressed air cleaning so that the debris blown off by a compressed air stream is contained from release to the atmosphere until vacuumed into a suitable vacuum device.  One such product, the COILPOD dust hood, which is depicted in the photo, is a bag-like structure covering the coils during the cleaning operation with two ports for the entry of compressed air (from either the exhaust port of a wet/dry vacuum or, preferably, a separate compressed air cylinder) and vacuum, respectively.

It appears that many of the owners of these commercial plug-in cooling appliances are failing to recognize the benefits that a planned coil cleaning program can contribute to their bottom line.  This is unfortunate since significant energy savings and prolonged appliance life are the results of doing the frequent cleaning to keep the coils clean. For more information, contact Richard Fennelly at or visit