How to choose a Commercial Dishwasher for your establishment
There are potentially many things to take into account when choosing a commercial dishwasher for your establishment.
Even if you have an existing commercial dishwasher which you are happy with chances are since this machine was purchased there have been many advances made in the types of commercial dishwashers and the features they offer.
Commercial dishwashers range in types from the very basic machines which offer many years of service up to the very advanced machines which also offer many years of good service but can also offer substantial savings during the period of this service and things such as insulation which make the machines quieter and save money.
It is quite a simple exercise to size a commercial dishwasher for a small to medium size establishment however it does take some homework.
The best way to do it is think about and document the potential amount of plates, bowls, cups, saucers, glasses etc. which will require washing during your busiest work period. For a café this may be breakfast, lunch or dinner.
For instance, in an Industrial complex it may be lunch when all the local businesses are staffed at their highest amount and they are all looking for lunch or just a cup of coffee.
Our sizing chart gives a good indication on the amount of items that will fit into a 500mm by 500mm square basket which is the industry standard for commercial dishwashers in Australia.
For example, say you have a 60 seat restaurant and you turn over each seat at least once and some twice during dinner. Then you need to think about what do most of the patrons eat? Do they all have entrée? Not always.
Once you have the figures in mind you can then transfer them to the sizing chart. From there you add a safety margin of around 10% and you have the estimated total of racks to be washed during the dinner service. Then you need to consider the amount of time you want to be able to process this amount of racks in.
If dinner starts at 6pm and finishes around 9pm then you have a time frame of about 3 hours if you consider plates will not be coming back for the first half hour and then you can wash for another half at the end of service as the final plates come back.
To establish the amount of racks which need to washed per hour then divide the total number of racks from the sizing chart by the time in hours. Once you have the total number of racks which need to be washed per hour then you can select the appropriate dishwasher to suit.
Remember, the capacity normally stated on a dishwasher brochure is a theoretical one and is not possible to achieve. This is because just about all manufacturers rate the machines off the running time in seconds without allowing for any change over time in between.
For example, if the shortest cycle on the dishwasher is 60 seconds then the maximum capacity in theory is 60 cycles an hour, or 1,080 plates if loaded at 18 plates per cycle. However, this is not possible to achieve in real life. You have to allow for change over time for the racks.
Change over time is normally influenced by the area in which the operator is working and the amount of staff assigned to the area. For the sake of this exercise we will assume there is only one operator in the area.
If the area is well laid out and is not cramped then the change over time will be less. If the area is cramped and has a lot of traffic through it from the chefs and waiters etc then the change over time will be extended. If you are not confident in establishing a change over time then elect between 20 and 30 seconds per cycle.
This would equate to a machine which has a 60 second cycle doing 40 cycles in an hour allowing for a 30 second changeover time. This may sound like a lot of time between cycles however there are many times when a rack is not ready to go straight into the machine and the operator has to also unload the clean items which are coming out of the machine.
(Quantity/No. Per Rack = No. of Racks)
|Trays||Max length 450mm||6|
|72||Dinner Plates||Diameter 260mm||18||4|
|88||Side Plates||Diameter 160mm||22||4|
|66||Entrée Plates||Diameter 160mm||22||3|
|48||Soup Bowls||Diameter 160mm||16||3|
|64||Desert Bowls||Diameter 160mm||16||4|
|125||Coffee Cups||Diameter 85mm||25||5|
|144||White Wine Glasses||Diameter 75mm||36||4|
|144||Red Wine Glasses||Diameter 75mm||36||4|
|108||Beer or Soft Drink Glasses||Diameter 75mm||36||3|
|40||Serving Dishes||Max Length 450mm||4||4|
|500||Cutlery Laid out loose or in containers Approx.||100||5|
|Plus Safety factor of 10%.|
|Note quantities are indicative and depend on the depth of plates and the type of rack.|
|TOTAL NO. Racks||72|
Once you have sized the machine you need, then it is time to choose the commercial dishwasher that best suits your needs.
There are many factors which can influence this choice including,
- Features & Benefits
- Required services
- Service Backup
- Warranty offered
- The wash up area
Let’s look at these one at a time.
As with most things there are a huge amount of models, makes and variations on the market.
All these have certain features which can vary the cost.
Sometimes though it comes down to the fact of you simply want the cheapest machine you can get. This means you have to shop around.
Features & Benefits
Over the last few years there have been tremendous strides made in this area.
Some of these that are on offer include,
- Insulation which cuts heat in the area, stops the chance of the operators getting burnt from the door or hood and reduces energy loss which saves money.
- Reduced water usage through better designed rinsing systems, which also save money on water & chemical usage but is also good for the environment.
- Water filtering within the machine saving time and also giving better results.
- Inbuilt chemical dosing equipment which gives you the freedom to choose any chemical supplier and also makes dosing easier.
- Electronic controls with many features.
When replacing a machine that is built into a bench if the new machine is the same width bench to bench then chances are you will not have to pay for alterations to the bench work. This could save many hundreds of dollars.
Also check height to ensure the new machine will fit under your bench or exhaust hood.
As with size if you are replacing an existing machine check what services you have at the moment in the way of power, drainage etc. Also consider if the machine is rated at over 8kw then you should have an exhaust hood built in over it to extract the air from the area or you can purchase a machine with an inbuilt condensation hood. Further talk to your Chemical supplier and ask them what is involved in connecting to a new machine and what if any costs are you up for?
If you are changing over a machine which has given you good service over many years, then this is a recommendation in itself. Ask around and seek advice. Talk to neighbouring businesses as you may find one of them has just been through the exercise of changing their machine.
Ask to speak to a few customers that have recently bought the same machine you are looking at.
Ask the Dealer or supplier how is the new machine backed up? This is particularly important if you are based in a remote area or Country Town. The cheapest machine may not be a good choice if there is no one trained on how to service it in your area.
Ask what the most expensive parts are and how likely are they to fail?
Ask about spare parts holdings for the machine you are considering?
If the model you are looking at is new to the market, then be vigilant as to how can it be repaired and what parts are in stock here in Australia.
Also check on what maintenance programs can be offered. Just like a car, dishwashers should be maintained. This has become more important over the last few years due to the effect of drought in many areas. Commercial dishwashers use water and heat it to a point where the water will undergo a chemical reaction. This can cause calcifying of elements within the machine, deposits in the wash chamber and in serious cases corrosion.
If you are in a Hard Water area, you may need to consider some form of water treatment to protect the machine.
There are choices in the market on different warranties which you should look into. Some manufacturers or importers offer extended warranties and some also offer after hour warranties.
Check what is covered by the warranty and just as importantly what is not covered.
Ask if the machine breaks down after hours (when most restaurants are operating at their peak) what is the cost to you and what does this cost cover?
The Work Area
The work area where the dishwashing is done has a big impact on the time taken and the results achieved. Ideally there should be a drop off area for dirty plates and items to be placed after they are removed from the tables.
There also needs to be an area for at least one rack which is to be loaded.
Preferably there will be a sink with a pre-rinse spray mounted over it so the plates and bowls etc can be rinsed before they go into the dishwasher. On the outlet of the machine should be an area for the unloading of the clean items and storage for the clean items once unloaded.
Care should also be taken to help avoid “Cross Contamination”. This is when clean items are re-contaminated after being cleaned by crossing into a dirty area, or being handled by a person who is also handling dirty items.
Therefore, there should be good hand washing facilities within the wash up area, to help avoid this.
As you can see there are many things to consider when looking to purchase a dishwasher.
Fortunately, if it seems too daunting then you can contact a reputable dealer or supplier who is well versed in these matters.
Water does not always behave the same way when we clean with it. Some of the minerals it contains can inhibit performance by leaving those familiar ugly and unappetising smears on cutlery and glasses. In dishwashers they may deposit a fur commonly known as limescale.