Warewashing, or dishwashing, is a major part of any food service operation and a clear
target for any initiatives to improve sustainability. Inefficient processes can use a lot of water,
electricity, and products but reducing consumption will have a positive impact on the
sustainability of any application. While the drive to zero carbon is a clear medium to long
term objective for many, the increases in electricity prices ? and to a lesser extent water
costs - over the past year or so have placed a sudden and extra burden on all businesses to
reduce costs.
The significance of warewashing should not be underestimated. It is connected to 60 percent
of what happens in a kitchen and has a major impact on operational efficiency. It follows that
there are potentially significant savings to be made on day-to-day operations. But
warewashing is important for other reasons too. Disruption to processes and poor results
cost money and can negatively impact on customers? experiences, perceptions, and
satisfaction ratings. And that can lead to less repeat business and fewer new customers.
There are many potential opportunities to improve the sustainability of any warewashing
operation. The first step is often to decide on objectives. These might include simpler
processes, cost savings, better results, improved sustainability and so on. Choosing the right
equipment and cleaning products and learning how to use them properly will support these
objectives.
With any equipment purchase it is important to match the machine to the workload. Machines
that are too small can struggle through overuse, leading to inefficiency and unreliability, while
those that are too large will be under-utilised and not cost-effective. It is also important to
choose cleaning products for optimum performance. This choice will be determined by a
number of factors including the specific application, the type of machine, the
hardness/softness of the water and so on.
Moving on to specifics, the simplest energy-saving measure that any food service operation
can take is to make sure that warewashing equipment is used correctly, with the right
products, and maintained and serviced regularly. This will minimise any energy, water and
cleaning product wastage associated with inefficiencies, unscheduled downtime, and
machine unavailability. But there are several ways to go further.
Reduce Energy Consumption: energy accounts for about 10% of warewashing costs. If the
machine is heating water to an excessive temperature, has faulty temperature probes, or
clogged with limescale it will probably be using more energy than necessary. Also, if the
machine is left on for long periods without being used or is only partially filled it can be used
too often and that will also waste energy. Costs will soon add up. Therefore, wherever
possible, always fill the machine (and do this correctly) before using it. Turn it off when it is
not being used. Any hot water leaking from the machine will mean more energy is required to
heat the replacement. Ensuring good maintenance is critical for optimum machine
performance. Make sure the machine is used in line with the manufacturer's
recommendations, used with suitable products, checked regularly, and serviced at the correct
times.
Reduce Rewashes: estimates suggest that in commercial settings rewash rates are around
10 per cent. That means one in ten runs of the machine will require a rewash. This wastes
time and uses energy, water, and products. Ensure staff understand how to use the machine.
Use the correct products. High rewash rates are often attributed to non-optimised processes
that also increase per-rack costs. Estimates also suggest between two and three percent of
dishwashing costs in food service and hospitality result from breakages, when kitchens are
forced to wash dishes manually or have a high rewash rate that requires more handling
(increasing likelihood of breakages).
Maintain Equipment Correctly: poorly maintained equipment will be inefficient which will
lead to higher energy consumption, more rewashes, and unscheduled outages and
downtime due to equipment failure. Make sure the machine is checked regularly and
serviced at the correct intervals.
Remove Limescale: when limescale builds up on heating elements and other components
inside warewashing machines their thermal efficiency ? the ability to transfer heat - is
reduced. This means more energy is required to heat water up to the optimum operating
temperature making the machine less economical. Each millimetre of scale inside the
heating element will add around eight to ten per cent on energy costs for a typical
commercial machine. Introducing water treatment equipment or cleaning products formulated
to prevent or remove the build-up of limescale will offer a good return on investment.
Limescale can also restrict the passage of water and impact on the equipment's reliability.
Preventing it will therefore help keep the machine working properly so there are fewer
unexpected outages and less downtime.
Many of these changes can be implemented quickly and easily with little or no additional
upfront investment. When more significant change is identified it becomes much easier justify
an investment when energy or water prices rise because savings offset the costs much more
quickly. Reputable suppliers will be able to advise on the most energy-efficient combination
of their products for specific applications. They will support their claims with proper
documentation and may have tools and calculators to help assess savings.
Warewashing forms part of Diversey's Washcraft service that is based on decades of
expertise and experience in delivering highly effective and sustainable solutions for
commercial laundry and kitchen hygiene. Washcraft is a feature of Diversey's display on
Stand E30 at The Cleaning Show. Other sustainable products and services on the stand
include the TASKI Swingo 250 and TASKI ULTIMAXX scrubber driers, the SafePack
ultra concentrate system, and the SURE range of plant-based, 100 per cent biodegradable
cleaning products.