Reverse osmosis has been held up as an effective solution to the challenge of getting glasses clean, but some operators argue that it is relatively water intensive and makes the capital cost of the machine more expensive. Is RO therefore a luxury? FEJ finds out from those in the know.
The task of washing dishes and glasses can be a complicated business, especially for restaurants and operators working in areas notorious for hard water or where only the very best quality rinse water will do.
Unless fitted with suitable water treatment, glasswashers suffer greatly when installed in hard water areas. The Carbon Trust estimates that for every millimetre of limescale built up on electrical elements, energy consumption is increased by 7%. This is a particular problem were limescale can build up at an alarming 1mm per annum.
Components in the machine quickly start to suffer, too; filters, solenoids and wash and rinse jets become blocked, elements and boilers can split, detergents become inhibited and less effective, results quickly deteriorate and the expected lifespan of the glasswasher is compromised.
In some instances, further water treatment may be required and this is exactly where de-min and reverse osmosis units come into play, says Bob Wood, director of DC Warewashing & Icemaking Systems. “They can prove very beneficial as they will help remove the impurities from the incoming mains water,” he says. “Be aware, however, that both can be expensive to implement and that RO units use a lot of water to create just one litre of pure water, in some cases as much as 4:1.”
Wood’s view is that in most cases a suitable softener, the correct rinse temperature and water pressure, combined with suitable chemicals and appropriate dosing will give sparkling results time after time.
But there are those that believe RO brings the peace of mind that a lot of operators want as well. For caterers that are handling a lot of delicate stemware, and want a perfect end-result, the proof is in the pudding, says Adam Lenton, marketing manager at Classeq.
“Reverse osmosis removes approximately 98% of water impurities by filtering through membranes. Removing these impurities in this way means your glasses will be left residue-free and won’t require polishing to achieve sparkling results,” he comments.
John Shepherd, UK and Ireland country manager at warewashing manufacturer Wexiodisk, endorses this view, noting that RO is usually required for establishments in need of a solution to constant polishing, which can be extremely time consuming.
“Fine dining restaurants or function sites with a large volume of glassware will benefit from RO significantly as it will reduce the excessive staff labour required to keep the glassware polished to a high enough standard consistently and throughout service,” he says. “In terms of a regular bar or restaurant, RO could be considered a more expensive luxury, which may provide little benefit to their business.”
Tim Bender, sales director at Hobart Warewashing, thinks it is a mistake to consider reverse osmosis as a luxury and suggests operators should avoid looking at it that way. “Yes, it does use more water to operate and does mean the capital cost of the machine is slightly higher, but the premium you pay is nothing like it used to be,” he insists. “It’s a case of horses for courses; if you have high quality glassware and want the perfect result every time without polishing, then reverse osmosis makes perfect sense. What we don’t think makes so much sense is recommending reverse osmosis for dish and pan washing. That, to us, constitutes a waste of water.”
Those in the game of providing integral reverse osmosis systems, such as Meiko, argue that they actually use much less water than a comparable softener. So how much water exactly does something like the Meiko GiO unit discharge to drain compared to a cabinet-type water softener?
“For a Meiko machine with a 2.6 litre final rinse water volume and with a 30-rack-an-hour throughput, the total final rinse quantity will be 78 litres, of which the reject rate will be 20%,” explained UK MD, Bill Downie, prior to his retirement from the industry last month. “Based on a 10-hour operating day, a front-loading or pass-through machine fitted with a GiO module will have a total reject rate in the region of 156 litres per day. This compares to a traditional 14 litre/18 litre resin base water softener regeneration reject rate of approximately 455 litres.”
Ultimately, the industry appears to agree that reverse osmosis is a highly effective process, but suppliers also urge operators to speak with them before making any decisions to establish whether the investment is necessary and how to get the best from it.
Paul Crowley, marketing development manager at Winterhalter, says: “RO is not a luxury if spotless results and no polishing is required, especially where sites are using expensive stemware and want to reduce breakages. However, RO is expensive and costly if a standard wash result is all that is required. Customers should take responsible advice before investing in RO.”
Smeg’s commercial channel director, Phil Coulstock, comes down on the same side of the fence. He acknowledges that RO can add to both the running and maintenance costs of a machine, but says that this is easily offset against any labour costs for sites where hand polishing is carried out. “If a site is spending many hours hand polishing glassware then RO is a long-term cost saving investment; if the site doesn’t hand polish glassware then, yes, it is a luxury.”
In conclusion, then, RO can be an expensive capital solution for water preparation and experts acknowledge that high volumes of water are consumed in the process of stripping contaminates from the membrane. But if a site requires the ultimate result in product washing, sparkling glasses and high-finish crockery, it should be given serious consideration.
What is reverse osmosis?
There has been an increased level of marketing promoting reverse osmosis as the ultimate solution in recent years, but what exactly is it?
Julian Lambert, sales director at Maidaid Halcyon, explains: “RO, in essence, is a very simple device that pushes water at high pressure through a very fine filter (membrane). This has the effect of stripping impurity particles, leaving very pure water. Maidaid Halcyon has conducted numerous field trials with many different RO products with the assistance of Crystaltech Services, the UK’s premier warewashing installation and service company. RO provides the best solution for customers requiring the ultimate sparkling clean glass, with most field trails being conducted in partnership with major brewery chains.”