All good in the hood: How to specify the right dishwasher

Maidaid Evo 2035 WS HR hood-type dishwasher

Hood-type dishwashers have historically been one of the largest energy consumers in the kitchen but they are also in a position to be one of the greatest savers thanks to advancements in warewashing technology. FEJ canvassed the industry’s leading brands to find out what factors operators really need to bear in mind when purchasing hood-type dishwashers these days.

What are the most important factors an operator needs to think about when investing in hood-type dishwashers?

The decision on which warewashing equipment is best suited to a particular establishment ultimately boils down to the type of products being washed inside. If you’re looking to primarily wash crockery, cutlery or glassware (separately to the crockery) then a standard hood machine will suffice if the capacity suits. On the other hand, if the requirement for a hood machine is to wash pots, pans and gastronorm type trays, then a machine with a greater hood opening or perhaps the ability to alter the pressure of the wash arms to turn the appliance into a pot washer, for example, might be preferred.

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Specifying the right model comes down to asking a number of questions: what needs to be cleaned and in what timeframe? Do you have a continual through-put of product and are there peak times of activity? Do you need to have a machine with the capacity to deal with peak demands or can the site process at a steady rate?

“Depending on the mix and the menu offering, they may require a machine with multiple cycle options or even specialist cycles such as intensive cycles for the more difficult products,” suggests Julian Lambert, sales director at Maidaid.

He adds that other major considerations include the available space and services in the kitchen. “When purchasing a hood machine, space for prewashing and unloading tabling must be allocated and be of sufficient size to enable operators to use the machine effectively. On too many occasions we have received requests to downgrade a machine’s power requirements after its has been delivered due to insufficient power being available. This consequently means the equipment can never function to its full potential.”

As with so many sites, space can often be at a premium, so the requirement for a hardworking warewasher with a moderate footprint, is crucial.

“For instance, a medium-sized site serving 100-plus people would typically require a passthrough machine with tabling, to ensure the kitchen retains its momentum, yet even this could fit within a modest three-to-four metre length on one side of the kitchen,” says Tim Bender, UK sales director for warewashing at Hobart UK, which produces the Premax AMX and AUP hood-type machines.

Haubenspuelmaschine_AUP_Bistro_001“Put simply, the hood type warewasher is the perfect compromise for medium to large-sites that crave performance and speed without the typical footprint of a flight-type machine. Of course, hard work and multiple washes must not come at the expense of energy efficiency. Thankfully, most operators can accommodate both requirements if they choose a machine that has been designed to stand up to the rigours of a modern kitchen — especially in light of a new wave of all-day dining which can put even more pressure on operations.”

Inlet — or ‘dirties’ — tables need to be of an adequate size, complete with a pre-rinse sink, a spray unit and, if needed, waste disposal, in order for the operator to sort, stack and pre-spray wares ready to be washed. Similarly, suitable space must be left in the form of an outlet, or ‘cleans’, table for crockery to dry, as well as sufficient storage for crockery, baskets and detergents, both during operation and at the end of the day.

When considering the dishwasher itself, it’s key that the size of the machine is matched to the amount of items being washed and the time allocated for each cycle, says Steve Bowler, category manager for warewashing at Electrolux.

The hood-type warewasher is the perfect compromise for medium to large-sites that crave performance and speed without the typical footprint of a flight-type machine”

“Once this has been determined, specifiers should think about the services available on site — whether there is hot or cold water available, whether the electric supply is single- or three-phase, whether the machine requires a pumped waste for drainage, and whether there is an extract canopy available for ventilation purposes. It is also worth checking how the necessary chemicals and detergents are used within the machine, and questioning whether the hood-type is supplied with rinse aid and detergent pumps, as external dosing equipment will be required if not.”

Although the initial outlay for equipment is always important, it shouldn’t be forgotten that the whole life cost of a machine will be greatly affected by running costs, such as those for water, electricity and chemicals, as well as the reliability of the kit. For this reason, after-sales support is becoming an increasingly important issue.

Meiko UK’s managing director, Bill Downie, is even of the opinion that the discussion is moving away from ‘which is the best dishwasher’ to ‘who supplies the best dishwashing package’. “It is a crucial point of difference,” he insists. “Operators require highly cost-effective equipment, excellent washing results, but also top-quality service and support. They are not prepared to wait for up to three days for a breakdown visit on critical equipment, nor spend money on extended warranty options up front and then still get bills for non-warranty repairs.”

The green&clean Hood Type dishwasher from Electrolux Professional, winner of a Red Dot Award for Product DesignTo what extent is hood-type dishwasher technology evolving? Are there any new developments or features that operators should be aware of?

Ease of operation is the focus for many dishwasher manufacturers as they seek to answer the call for machines that are straightforward to operate.

Paul Crowley, marketing development manager at Winterhalter, says all the industry’s market leaders are moving in this direction. “Intuitive touch-screens and single button operation allow for quick and easy operation. The more advanced manufacturers are also investing in technologies that help reduce energy and water consumption. Heat exchangers and cleverly-designed wash arms all help operators reduce running costs,” he says.

As with the rest of the catering industry, warewashing technology is permanently evolving. The most recent development in hood-type machines has been the ability to supply machines with automatic internal water softening and heat recovery. “All additional features have to be fully appreciated before ordering a machine — not all supply the best operating package for the end-user,” warns Maidaid’s Lambert. “Very hard water areas may be best served by an independent water softening device and, for a machine with intermittent use, heat recovery may never provide the return on initial investment.”

With a constant stream of new developments in the sector, a focus on energy efficiency and a significant reduction in the usage of consumables such as water, electricity and chemicals, operators would be well-advised to consider not just the capital cost but how the savings can impact on the overall expenditure throughout the life of the appliance.

“Some of the most pioneering developments have come in the shape of pre-rinse machines,” says John Shepherd, country manager at Wexiodisk. “We have been able to pioneer pre-rinse machines that are able to use the warm, chemically-enriched waste water from the adjacent warewasher. The pre-rinse machine helps to extend the life and quality of the water in the wash tank by removing much of the crumb and contaminant prior to the dirty dishes entering the wash cycle, and by re-using the waste water to rinse it is able to save seven or eight litres of water per wash.”

Lifetime running costs are a theme for Meiko’s Bill Downie as well. He highlights integrated condensate hoods and heat recovery technology as innovative features, while the company’s ‘Point2 AirConcept’ is an air flow control system that reduces emissions of hot waste air on hood-type machines.

“When the hood rises, the hot air — which normally escapes into the dishwash area as steam — is instead captured and used to pre-heat incoming cold water. Depending on the configuration and site conditions, exhaust air volume reduction can be as high 90%. Fitted on a Meiko DV80.2GiO hood-type dishwasher, AirConcept reduces the connected load from 8.5kW to 7kW, a 17% saving in energy.”

Other manufacturers have also been working hard to implement new advancements that improve the dishwashing process. Smeg, for instance, has spent the past two years remodelling and designing new concepts for heat recovery units, and these will be introduced to its machines from 2016.

Winterhalter's energy saving PT passthrough warewasherPhil Coulstock, commercial channel director at Smeg, says operators will see noticeable improvements in efficiency and cost for the drain heat recovery and steam heat recovery units. “The other area Smeg has been concentrating R&D into is machine control panels, making them more informative and user-friendly,” he reveals. “The user interface has easy-to-recognise symbols to control a range of functions and perhaps the most significant is the Bluetooth capability. This will allow the Smeg dishwashers to connect to smart phones and tablets, providing real-time operating data on factors such as water, power and chemical consumption.”

Operators will be alerted to any error codes and fault diagnostics quicker, too, making early intervention on potential problems possible. Bluetooth will also allow new software to be easily uploaded into each machine. “We think this a very significant innovation for Smeg dishwashers and for commercial dishwashers in general,” says Coulstock.

With food safety a prime concern for foodservice outlets, filtering has also become a key feature of the latest generation of hood-type dishwashers. “Keeping the water inside the machine as clean as possible means that the wash tank can be smaller, reducing the amount of detergent and water needed, as well as the energy used to keep it up to temperature,” says Bowler at Electrolux, whose ‘Clear Blue’ filtering system on its green&clean model ensures wash water remains free from food residue and other contaminants.

“More and more, manufacturers are refining the technology within HTs to exploit the ‘free’ energy of the machine, using the steam generated by the wash and rinse cycles to pre-heat the incoming water supply,” he says.

Filtering has been a major focus for Hobart, too. Its ‘Permanent-Clean’ filter system directly pumps all the soil carried into the machine out of the dishwasher, meaning dirty plates can be stacked directly in the rack.
“The more fine and coarse soil carried into the dishwasher, the dirtier the wash water gets,” says Tim Bender. “In the past this would have meant the water needed emptying and refilling several times a day. The revolutionary filter system removes this need at a stroke, transporting all residue away from the dishwasher.”

Above all, warewashing equipment needs to be highly functional and energy efficient, says Kris Brearley, sales director at RH Hall, a partner of Smeg. “Operators should look for double-skinned models that keep heat loss and noise levels to a minimum, as well as internal water softener systems if you are in a hard water area,” he says. “The number of programs available will offer greater versatility in terms of the items being cleaned and the intensity or length of the wash cycle.”

DV125What are the biggest misconceptions when it comes to hood-type dishwashers?

Specified in the right environment and operated correctly, hood-type dishwashers will help a foodservice operation keep a handle on all their warewashing requirements, nullifying any concerns that such systems are expensive to buy and operate. “The higher throughput you gain from having a hood-type dishwasher will be cost-effective long term due to the machine being higher powered, producing a faster heat recovery between wash and rinse cycles,” says Bob Wood, director of DC Warewashing & Icemaking systems.

While some customers may think that hood-type dishwashers will take up too much space, Wood argues that this is outweighed by the added benefits of speed and efficiency. “The additional pre-wash sink and tabling will allow dirties to be pre-rinsed, washed and then slid out onto a cleans table. This allows a continuous cycle of washing that can be managed by one staff member with relative ease. If you are worried about space then a hood-type dishwasher can fully operate on its own without the need for a pre-rinse unit or tabling and still provide a higher throughput for you and your business.”

Operators have traditionally seen hood-machines as labour-intensive tools. but This doesn’t have to be the case”

Maidaid’s Julian Lambert says the main misconception about hood-type machines is that if a system offers a number of cycle options then all cycles will give good results washing any product. “This is simply never true,” he says. “Cycle options are designed to enable different levels of soiled items to receive different exposure to the mechanical and chemical action during the wash cycle. Many manufactures claim a one-minute cycle that operators then believe indicates they can run 60 cycles an hour — they then have the machine connected to a cold water supply where the manufacturer states optimum operation is achieved on hot fill.”

The perception that hood-types can cope with absolutely everything thrown at them is misplaced, agrees Winterhalter’s Paul Crowley. “They are great work-horses but they have limitations at peak hours, which can frustrate some operators. Getting a well thought out system can help alleviate some of these bottlenecks.

Dishwashers are a big investment so be sure to look at build quality, life expectancy and associated running costs. Don’t forget the wider picture and think about workflows, tabling, baskets, water treatment — even chemicals. They all contribute towards the efficiency of your hood dishwasher and overall catering operation.”

Operators have traditionally seen hood machines as labour-intensive tools given the need to open and close heavy hoods. This doesn’t have to be the case, argues John Shepherd at Wexiodisk. “Modern day appliances such as those in the Wexiödisk range now come with the option of auto-start functions, designed to close the hood and start the cycle once a basket has been placed on the rack,” he says. “This can not only save time but also the associated injuries caused by over stretching and lifting. Finally, many operators see the warewasher as the most energy-intensive appliance in the kitchen. Modern developments and technological advancements have given operators the opportunity for some of the biggest energy savings found in a busy professional kitchen setup.”

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Of course, not every machine is the same. After all, manufacturers use different wash systems inside the machines, and wash results will vary as a result. Additionally, the notion that one type of basket will be suitable for all washes is a falsehood, says Steve Bowler at Electrolux. “There are different baskets available for a reason. To get the best wash results out of the machine, outlets will need a suitable quantity and selection of baskets to suit the amount and type of items being washed. This can be as simple as using tray baskets for trays and glasses baskets for glasses, but will ensure that the machine washes items to the best of its ability.”

For Phil Coulstock at Smeg, the biggest misconception is that ‘best price’ should be the lead factor. “Not all hood machines are suitable for all kitchens and getting the specification correct first is very important. Only once the correct model is identified should price become a factor to the buyer, but even then there are other factors to consider including installation and correct setup, training and ongoing maintenance.”

Tags : catering equipmentDC ProductsdishwasherHobarthood-typeMaidaidMeikoWarewasherWinterhalter
Andrew Seymour

The author Andrew Seymour

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