Mop up the savings through water efficient cleaning
May 28th 2010 Cleaning equipment has been added to the Water Technology List.Claire Sweeney, Envirowise water specialist explains the reasoning behind it
Cleaning can account for up to 70% of a business’ water usage, resulting in costs not only through water supply bills but also through disposal of the resulting effluent. From filling a bucket for mopping floors to running water for large scale industrial cleaning processes, as soon as you turn on the tap the charges start to flow in. Yet there is scope for companies of all sizes and across all sectors to save money by adapting their cleaning processes to optimise water use.
In order to start maximising the benefits of waterefficient cleaning,you should begin by carrying out a full appraisal of your water use and cleaning needs on site.
This should include drawing up a water balance – a numerical representation of where water enters and leaves your business and the amount of water used by each process. Consider the possibility of leaks in the system,as even water which is wasted through leaks will be accounted for and charged to the business. A single dripping tap, for example, can waste up to 5000 litres of water per year.
If water use is limited to daytime operations, it should be nearly zero during the night. If this applies to your company, then carry out a night flow test by reading the meter when everyone has left and then again the following day before work starts. The meter readings should be almost the same. If not, you may have a leak, overflow or uncontrolled water use and further investigation is required.
Once you have a clear idea of your water use, you can consider options to improve water efficiency during cleaning processes.When it comes to cleaning offices, kitchens and bathrooms, even simple steps such as turning off taps when not in use, installing push-button or spray taps and only switching on dishwashers once they are completely full can make a major difference.
For large scale cleaning tasks, hoses and other lowpressure, high-volume methods use vast quantities of water and are a less efficient way of cleaning sites and equipment. Consider switching to spray jets instead, which can achieve water savings of 20% over standard hoses.
Manufacturing sites are often those with the most water-intensive cleaning processes and there are several water-efficient options which can be considered here. Cleaning-in-place (CIP), for instance, can deliver major advantages on production lines by cleaning machinery with little or no disassembly. CIP systems reduce the amount of chemicals and water used because they spray the inside of machinery rather than relying on filling and soaking pipes.They can also recover fluids and product, enabling subsequent re-use and increasing overall levels of efficiency through greater automation. To harness their full benefits, however, they need to be carefully monitored to ensure flow rates, cycle times and temperatures are optimised.
In addition, companies could explore installing control and monitoring devices. These include leakage detectors,as well as technology such as turbidity probes, which sense changes in liquid concentration and can indicate when cleaning is needed or can be halted. What’s more, auto shut-off systems can be used where a constant stream of water is not required,avoiding excess water ending up down the drain.
Sites which use water for cleaning, as well as other processes such as cooling, heating and quenching, could also benefit from water recovery and re-use systems, which enable companies to re-use a percentage of their wastewater for applications where a potable supply is not required. Such systems include membrane filtration, which offers a high level of purification and requires little energy to operate. The quantity of water re-used at a particular site is dependent on the level of treatment needed, but recovery and re-use efficiencies can be up to 90%, with payback periods as low as 12 months. Finally, companies which operate industrial cleaning devices can also consider scrubber/driers and steam cleaners.
Scrubber driers can be used in a variety of settings but are likely to be most effective in locations with large flooring areas and easy access, such as factories, supermarkets and warehouses. They are fast and efficient and can contribute to significant reductions in chemical use, water and effluent volume. Efficient scrubber dryers can clean more than 60 square meters of floor with a single litre of water and some of the most efficient models include an integrated washwater recovery and re-use system.
Steam cleaners can be used in a variety of working environments and offer reductions in water and chemical usage compared with traditional manual cleaning methods. Using high temperature steam, they sterilise the area, killing bacteria and breaking down grease without the need for chemicals, which could in turn save money on cleaning supplies. Steam can be used to clean floors, walls and ceilings, as well as industrial surfaces such as assembly equipment and ovens.
Any businesses which have already invested in such water-efficient technologies would be well advised to review their systems to ensure they are reaping maximum benefits. Spray or jet washing systems, for example, are generally very effective but the technology has advanced in recent years. Poor maintenance practices can also damage nozzles and reduce efficiency, so operators should ensure nozzles are descaled Many water-efficient technologies,including membrane filtration systems, CIP equipment and industrial cleaning devices, are eligible for 100% first year capital allowances as part of the Water Technology List (WTL).Managed by Defra and HM Revenue & Customs in partnership with Envirowise as part of the Enhanced Capital Allowance (ECA) scheme for water-efficient technology, the WTL enables UK businesses which pay income or corporation tax to claim tax relief on technologies included on the WTL, shortening the payback period and adding to potential cost savings.
For more information about the ECA scheme and to view the WTL visit www.businesslink.gov.uk/wtl To find out more about purchasing products from the WTL, to register a product for inclusion or to apply for certification for a membrane filtration or recovery and re-use system, visit www.businesslink.gov.uk/wtl or call 0800 585794.
HMRC has also published detailed guidance on the ECA scheme on its website
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