Modern business planning now demands application of best affordable practice in machine selection and operation. Shrewd house buyers will look at the ‘Energy rating’ of a property, with one eye on low environmental impact and the other on a major running cost. Shrewd launderers are looking at energy and water consumption and chemicals discharge, with a strong eye on the major costs of these, which dominate the wash costs and operating margin.
All washer manufacturers have trimmed their sump sizes and clearances between drum and rotating cage to minimise the volumes of water needed to make the wash and rinse dips. Most makers thought that they were now close to the minimum achievable, until the Hydrofinity design appeared, with advanced and highly innovative modern concepts.
Steps to Minimise Water and Energy Consumption With Each Wash
This month, our guest blogger, Steve Anderton, looks at steps which can be taken with every washing machine design to minimise water and energy consumption in everyday use, with useful benefits in productivity as well. Then we will look at the latest innovations which make one design in particular stand out from the crowd.
Check Water Levels
The amount of water required in the pre-wash and main wash to produce optimum soil and stain removal was determined many years ago by the British Launderers Research Association. This was expressed in terms of the ‘dip’ – the mean water level in the cage during rotation, measured from the inside of the cage at its lowest point. For machines up to 100kg capacity this was found to be a remarkably consistent 125mm for the pre-wash and 75mm for the main wash. The higher pre-wash dip was enough to flush off loose lint and food or vomit debris. The lower main wash dip produced much higher mechanical action for effective soil removal and enabled effective chemical concentrations at lower cost. These levels have stood the test of time.
The main disruption to this convention has come from Hydrofinity, which has produced a design which does not use dips and replaces much of the water from the process using its patented XorbsTM. This feature has the double benefit that the XOrbs demand much less heat to be raised to wash temperature, so they give an automatic and substantial energy saving as an additional bonus.
Big differences in water costs, with both conventional and modern designs, come in the water consumed. Water quality still varies appreciably from region to region, so where the local water contains substantial amounts of alkali (as on chalk downs and in other limestone regions where calcium carbonate dominates), then much higher levels of rinse water is needed than in laundries that use moorland water, which can be slightly acidic. By adjusting the rinse water consumption so that the alkalinity of the final water is no more than 0.4 g/litre above that of the incoming soft supply, the consumption for the process can be minimised without risk of ‘galling’ (so avoiding yellowing in drying, when any excess residual alkali is heated). This last step, to fine tune the rinse levels, cannot be performed by the washing machine supplier, because it depends on the local water quality. The local chemicals supplier is often best placed to give advice and to help with any essential titrations.
In the HydrofinityTM design there is much less chemistry to be diluted (because of the much lower water volumes used). This alone has a dramatic effect on water demand, even without rinse dip reduction to suit local water conditions in a conventional machine.
Lower Wash Temperature
Heat energy is expensive and often the majority still comes from burning fossil fuels, which makes it a major contributor to global warming. Lowering the wash temperature using a low temperature detergent is usually effective, but it comes with a financial cost (the detergent is more expensive) and an environmental cost (the discharge to drain is more reactive chemically and this can affect river, ocean and plant life). In the past phosphates from detergents have been linked to ‘eutrophication’ of European rivers, resulting in excessive nutrients for plant life, but depleting oxygen to the detriment of fish stocks. For this reason, phosphate is no longer used, therefore modification of detergent formulations (to remove phosphates for example) in some regions has corrected the worst of this, but the problem of chemical contamination remains.
Much has been made of wash temperature and the potential savings available by washing at say 40C instead of 70C. The claims can be impressive, and many laundries are now switching to low-temperature wash chemistry, but this is necessarily more aggressive than high-temperature products. It still results in strong chemistry being sent to drain.
Hydrofinity has come up with an ingenious solution, which probably puts it well ahead; its XOrbs, used to lower water consumption, have a dual purpose. By displacing the water volume in the washes, they reduce water demand and by attracting oily, fatty soiling and staining they eliminate the need for high-temperatures and much of the aggressive wash chemistry to emulsify and saponify oils and fats. It is this win-win feature which gets the oily staining off without so much reliance on harsh chemistry.
Chemical Discharge from Washing
Why is chemical discharge so important? The reason lies at ground level and in the upper atmosphere. At ground level, eutrophication of rivers and major reductions in fish life are only part of the problem. Chemical reaction to create ozone and other irritants to human breathing is becoming increasingly important, particularly as regards rising levels of asthma in children and young adults. In the upper atmosphere, the reverse problem occurs – ozone depletion to create holes in the protective ozone layer which shields human skin from the carcinogenic effect of the sun’s rays.
Compare Washing Machine Designs
So which machine design can claim justifiably to have addressed all of the various consumption and contamination issues in the laundry industry? There is one independent organisation which has tackled this conundrum and developed an internationally recognised suite of tests which measures energy and water economy, chemical discharge effects, contribution to fossil fuel depletion and so on.
SCS Global Services operates a scheme of assessment to identify features which make any particular washer an ‘Environmentally Preferable Product’ (EPP) and issues a quantified EPP performance certificate for those which meet its criteria for achieving genuine and worthwhile contributions to global environmental improvement.
The SCS methodology looks at any product from ‘cradle to grave’, assessing manufacture, operational use and final disposal. Its in-depth assessment of the latest Hydrofinity design makes remarkable reading. Its findings indicate performance results which make it significantly better than the average washing machine environmental performance, in every one of the key features needed for this claim to be credible. Even more impressively, its performance is actually better in every key respect than every one of the alternate machines with which it was compared.
The machine is rated 66 - 72% better than the typical mean for energy performance and 46 -56% better for water economy, which (after labour) are the main drivers for laundry operating cost. Even more impressively, it achieves major improvements in eutrophication potential, acidification potential, ozone creation at ground level and ozone depletion in the upper atmosphere. It is very rare that SCS finds a single product that ticks all of these boxes, but the Hydrofinity design has actually achieved this.
Of course, this makes demands on laundry management. It is no longer possible to just assume that the washers as delivered will deliver minimum cost production. Careful thought and planning must go into seizing the opportunities offered by the latest technology and there may be a latent demand for further training for the laundry manager, washroom supervisor and laundry engineer. Minimising rinse dips (for which there is great potential in most laundries) may call for titration of the final rinse dump to assess its alkalinity, which could well fall to the detergent supplier. But the prize will be worth the team effort in financial terms alone. When the environmental benefits are added in, the exercise becomes irresistible. Most laundry managers can only dream of trimming 66% off energy consumption and 46% off water consumption, with other hidden benefits along the way!
Organisations are increasingly taking environmental concerns into account in their business decisions, but basic steps to further reduce energy and water consumption also make sound commercial sense. It is possible to exploit green technology whilst still improving margins and, with sound management decisions, it is possible to minimise environmental impact whilst simultaneously minimising operating cost. If this follows the basic principles outlined in this month’s blog, there is a hidden bonus of improved productivity as well. For some organisations, raising output is even more important than the reductions achieved in operating cost, Minimising water levels and reducing main wash temperature shortens every cycle and really gets the laundry humming!