Eau Coolers are a leading supplier of drinking water systems so a question often arises such as "What is the hot water output capacity of a traditional hot & chilled water cooler?" or "How does it compare to a water boiler manufactured by one of the leading UK suppliers such as Instanta and Marco?"
A simple question – what are the answers?
The hot water output capacity of a 'traditional' water cooler can be affected by many things. The potable mains drinking water supply temperature, the ambient air temperature of the cooler location, any other nearby heat sources, the way the equipment is being used, how often it is serviced, have the scale reduction filters been changed to the manufactuers instructions and how old it is.
The incoming mains water temperature can also play a big part for any water cooler attempting to produce extremely hot drinking water for users on a regular basis. (It makes really no difference to a purpose made Instanta or Marco type boiler.)
Plumbed in water coolers have a fairly simple design when compared to hot drinks boilers and in producing ice chilled water they are brilliant. But when it comes to producing lashings of boiling hot drinking water they are definitely the poor relations.
What is the main reason to choose a water cooler in preference to a water boiler when hot drinking water is needed?
Normally because of the considerable difference in cost between purchasing a conventional Instanta or Marco type hot water boilers to a hot & chilled water coolers.
In life you genrally get what you pay for and in the drinking water industry things are unsurprisingly no different. There will always be a temptation to reduce site costs by placing hot & chilled water coolers instead of a combination of a stand alone water cooler and a stand alone water boiler. (Water boilers are available in table top, wall mounted and under sink variants.) Frustration boils over then in areas where the hot water demand outstrips its ability to deliver.
Out put differences
The main difference found in hot water output is down to the design of the heating system found in 'normal' coolers and in 'normal' boilers.
Tank sizes in hot water boilers are generally larger and specifically designed to only add small amounts of mains water, at regular intervals, to the tank in the re-filling process. This keeps the hot water temperature in the tank stable during the filling process.
On the other hand hot water tanks found in coolers are genrally smaller, typically no larger than 2 litres, not so well insulated and are always immediately re-filled with cold water any time hot water is dispensed from the taps. Depending on the quantity of cups dispensed, the temperature can vary greatly!
Lots of eau coolers boilers have programmable 7 day timers and are fitted with early warning indicators to indicate scale build up and filter changing times. With regular scale reduction filter changes, servicing is normally quick and very easy to accomplish.
Hot tanks on on water coolers are more difficult to service and have no scale build up warning indicators.
Instant Draw Off and Hourly Output?
Boiler manufactuers tend to sing off the same song sheet when dealing with how the boilers are rated in terms of how much boiling water per hour the products can dispense. Water cooler manufactuers are much more cagey on what you can expect in terms of what tempratures and volumes one can expect.
"Instant draw off" measures the amount of hot water which can be drawn, without dropping outside an expected temperature range. "Hourly output" assumes an optimum cup cycle followed by an optimum recovery time.
As an example the Instanta SureFlow 1501F is a 3kW rated boiler and has a heat up time of only 32 minutes from a cold standing start. It has a rapid draw off of 10 litres or to put it another way 60 cups in one go. The boiler has an hourly output of 27 litres which equates to 162 cups per hour. Plumbed in water coolers simply can not compete on these levels.
The Marco Ecoboiler Tap T10 is rated at 2.8 kW and also has a rapid draw off of 10 litres or 60 cups. It has a lower power capacity but can still offer 156 cups per hour.
Water Coolers struggle with hot water
Traditional coolers such as our Arctic Star 55 struggle to get any where close to this type of performance. The Arctic Star 55 has a Hot Water Boost buttion which can deliver 1.5 litres (only 9 cups) in one draw off. In practice this means that for most coolers the temperature is reasonably stable for only 6 to 8 drinks. After that the temperature will continue to drop (until it wil eventually be equal to the influent water temperature).
Our AA 4400X water cooler has a 3 litre cold tank and a 2 litre stainless steel hot tank. This is thermostatically controlled to between 87 and 92 degrees C.
Hot & Cold Water Coolers are only suitable for a few cups at a time, with a sufficient recovery time before next use. Forget water coolers as a source of boiling hot water in busy staff rooms or kitchens. They just won't cut the mustard.
kW rating of the Heating Element is the main driver of heating performance. Table Top or Undersink Boilers are generally in the range of 1.5KW to 3KW.