(Edited: 6 June 2016)
Electricity consumption by supermarkets in the US and France is estimated to account for 4% of the country’s total annual electricity use.
On a national scale that’s a staggering amount of electricity, with supermarket managers under constant pressure to reduce their store’s energy demands and operational costs.
One key to achieving this has emerged via a landmark study conducted by US experts ASHRAE (the American Society of Heating, Refrigeration and Air-Conditioning Engineers).
Modern cleaning methods are key
Achieving those gains, though, depends on using modern cleaning chemicals specifically formulated to thoroughly deep clean a HVACR system.
The heavy duty SuperClean and its sister product EnviroCoil – formulated for more regular maintenance routines – are both designed to clean outdoor condensers, but the indoor shop floor cabinets also need to be regularly cleaned to significantly reduce their running costs.
Note that it is only by deep cleaning to the metal – removing the baked-on dirt, grime and bacteria build-ups that clog, cling to and slow both evaporators and condensers – that these system’s running costs can be reduced so drastically.
Supermarkets: breaking down the problem
When we separate out the individual components of a typical supermarket’s energy bill, it’s clear that one single element stands head and shoulders above the others.
As we can see from the above breakdown by the US Energy Information Administration, refrigeration (the chillers, cabinets and freezer units, both instore and in stockrooms) accounts for the largest slice in the supermarket energy usage pie by a country mile: typically 45-55% of the total electricity used.
It’s clear, therefore, that any attempt to reduce electricity costs by supermarket and facilities managers must begin by tackling the energy demands made by refrigeration systems.
Introducing the solution
To do so they measured energy demand from the system for a week *before* cleaning and then again for a week after cleaning (concurring with ASHRAE Guideline 14-2002 on how to accurately measure HVAC energy savings).
To ensure the study was reliable and independent, the building owners hired a certified and independent testing, adjusting and balancing (TAB) company to test and calibrate their data collection methods and instrumentation during the trial.
The ASHRAE study
The 34-storey building in NYC has 1.2 million square foot of floor space which has to be cooled from 6am to 6pm using four large 30-year-old air handlers:
After testing during the first control week, SF-8 and SF-9 were taken offline for two days to perform a modern deep clean on both air conditioners. The two systems were then put back into service and tested in exactly the same manner for a further week afterwards.
In all, HVAC inspectors and TAB contractors continuously measured 54 different data points from the two air con systems for a week before and a week after cleaning, including:
After cleaning, the smallest air conditioning unit of the four – SF-9 – started punching well above its weight, adding an extra 19-22 tons of cooling capacity (an additional 67-77 kW), increasing its overall capacity by a massive 25%.
The thermal efficiency of the cooling coils in the cleaned systems increased by 25%, and condensate water temperature dropped from 3-4°C before cleaning to 1-3°C after.
The inspectors estimated that 100 tons (352 kW) of cooling capacity would be added to the building once all four air handlers had been cleaned and restored in this manner.
These kinds of savings make dramatic reading, and it’s important to point out that if these regular services also included cleaning evaporators in supermarket cabinets, costs for a supermarket’s annual energy bill would be slashed even further.
This is clear statistical evidence that very significant efficiency gains and substantial reductions in energy consumption can be made simply by cleaning and maintaining the air conditioning condenser on a routine basis.
More than ever, supermarket managers and operational staff must appreciate the importance of paying more attention to the state, cleanliness and efficiency of their store’s ACR systems.