Coffee Vans

[robman]

Hi Team, has anybody had a chance to see how the mobile coffee vans are powering their espresso machine and grinders etc. I thought a generator would be the obvious way to go, but a friend of mine got a coffee in Brisabne the other day and said he could not hear a generator going.

Regards Rob

[nunu]

Re: Coffee Vans

Usually theyre run off an inverter. Just takes the 12VDC from the battery and converts it to 240VAC. Downside is possibly running the battery flat if youve got the van off for a significant amount of time and are running the machines.

[robusto]

Re: Coffee Vans

Must be one hell of a battery! A machine running at, say, 2400 watts, would draw 200 amps. And thats just for one hour.

Even with a domestic machine at half that wattage, youd be looking at a one hundred amp draw.

(figures rounded for convenience, as a 12 V battery is actually a shade over 13V)
Robusto

[st33p]

Re: Coffee Vans

the one that stop by our office runs a small generator on the other side of the van.
Its not too noisy, thats probably why your friend didnt hear it??

[robman]

Re: Coffee Vans

st33p, It would have to be a fair size generator, to run a coffee machine, most 2 group machines pull between 15 and 20 amps depending on the element size. Can you smell petrol/ exhaust fumes come from the van, that would not be a good experience when buying coffees? Is it a big van or a small panel van type with the machine sliding out the side?

nanu, I had a mate who said he thought they run off an inverter, they must have a stack of batteries on board to do this. I estimate that a 150 amp battery would power a two group machine for about 5 minutes, so you would need ten 150 amp batteries to run a machine for about an hour. They may have someway of charging them during their coffee round.

Regards Rob

[Burlof]

Re: Coffee Vans

My aunty is in the process of buying one of these vans. I was going to direct her to this forum anyway as I thought it might be useful for her so she might pop in here and answer your question.

[Fresh_Coffee]

Re: Coffee Vans

Generally speaking...

By far the simplest method is to use an "expensive" / high quality, low noise generator. Builders generators are not the go,...theyre cheap but theyre extremely noisy, very heavy to move around for the type of electrical capacity required, and the power they produce is "dirty" and not really suitable.

You can set "quiet" generators up in a special insulated compartment in the van, feeding off the same fuel supply as the van (so you dont have the inconvenience to fill it up seperately), petrol or diesel, vented both for cooling and for escape of exhaust.

The inverter thing is not as simple as you might think. The battery banks required are very large and can take up a lot of room in the van (say under a false floor),  are very heavy and very expensive. The kind of alternator required (on the van) to keep a "top up" charge going between stops (if required) .....is also expenisve aftermarket fitment. The main charge is done over night when you plug into the 240V charging system at home while the van is parked up.

Remember you are not just feeding the espresso machine & grinder...if you comply with health regulations and depending on where you are you *may* need a small hot water system (athough admittedly this could be a gas fired jobbie) and you may or may not run ancillaries (however small) like fridge etc.  Gas powered fridges such as are used in caravans are not the go....they are extremely slow to cool and wont work on any kind of slope...may as well use eskies & ice, much better!!!!!

When we sell espresso machines for "mobile" use we either remove the 15 amp element & replace with a 10 amp job, or we disconnect one of the multi part elements to reduce the amperage/wattage down from 15 amps to roughly 10 amps....depends on the type of element. This still doesnt account for the total capacity that a generator or inverter system would be required to feed, with the other appliances in the system that may cut in from time to time...which could take it up over 15 amps depending on what you are running (and therefore it takes you back up to bigger heavier more expensive generator / inverter systems.

The choice of espresso machine is therefore important.....a 2 group machine is not a 2 group machine (as in "oils aint oils"...), and a machine with a large boiler and therefore good steam capacity (like ours) is preferable to something with a small boiler with little capacity.

All this kind of explains why, its actually a lot more expensive to set up a van *properly* with the right type of equipment, than many people think.

Regardz,
FC.

[Framey]

Re: Coffee Vans

Hi Rob,
I was drinking some of your tasty coffee about an hour ago  


Good old google turned up:

Mobile Cafes are literally “a cafe on wheels”. Each custom-built Espresso van features an espresso machine, coffegrinder, blender, fridges, even hot water – all of which are powered by a generator concealed in the body of the van.

Edit : FCs answer covers it (as usual   ) he must have posted while I was writing my post. I type fairly slowly

[robusto]

Re: Coffee Vans

I lament the fact that when we go boating -- that spells the end of the home espressos, and its back to cafe-bought lattes and stove tops.

My smal generator can only handle 650 watts continuous --just half the power the Silvia draws. An invertor is totally out of the question, as the battery would need to supply almost 100 amps to it (for 1 hour). No lead-acid battery can be totally discharged, or even half discharged, so for ONE solitary espresso session including warm-up, you would need several expensive deep cycle batteries. In turn, these would then have to be re-charged from their depleted state. The boat alternator is incapable of doing that ---and of course, theres no 240V for a battery charger, and no charger is capable of that capacity anyway.

Not to mention having power cables to the inverter the size of jumper leads and then some.

The only answer is a very heavy, bigger capacity generator, or something like the lighter-weight Honda 4-stroke, 2KVA, which costs around $2000.

That works out at an expensive coffee, folks.

Robusto

[A_M]

Re: Coffee Vans

Spent some time looking into this line of busness and in general you have two options ..

1: Generator that could be either Petrol or Diesel – Costs as well as the type of Van you are getting has an impact.
a) If the Van runs on a particular fuel then the best option is to have the generator run off the same and thus you can then have the jenny’s fuel line plumbed…
b) If different then you have to fill the jenny’s onboard fuel tank and that can lead to vapours and the potential for a fire or worse !!!
c) The other issue is that the new Diesel units are quite, have heaps of grunt but cost HEAPS.
d) With the right size, you can have the grinder on, a 2 group head unit pulling coffees, the fridge and a juicer etc as well as your Hot water in the sink all working at the same time.
e) When travelling the jenny is off, so the first thing you do when you pull up is to kick the jenny over, and while you are off getting orders etc the units comes up to Temp and to pressure.
f) The unit is usually on slide out rails – ease of servicing and removal is you need it for something else.
g) If you are on site where there is power then you do not need it :-)


2: Inverters – Solves all the issues re fuels etc well sort of.

a) Usually they are a lower KVA system so you have to be a little more aware of what you need on and when. The higher KVA units cost more and you have to look at the battery system you are using.
b) The fridge usually is kept cold via ice bricks or other heat transfer method. Up here in Brisy by midday they are exhausted and thus the drivers will stock up with ice or call it a day.
c) You leave the Van running the whole time as you need to be charging the battery /s
d) What you save in jenny fuel, you now use by the Van as it has to idle for most of the day
e) You also need more or larger freezers at home to store the extra ice or condition the heat transfer medium



At the end of the day there is no clear cut winner as it depends on a number of variables, with the important being the Health inspectors and the Main roads making a call on what configuration is OK by them.

For me I will take the Generator for a number of reasons, some of which are best kept to myself, with the main reason being that it allows more flexibility.

[TEPIN]

Re: Coffee Vans

I lament the fact that when we go boating -- that spells the end of the home espressos, and its back to cafe-bought lattes and stove tops.

My smal generator can only handle 650 watts continuous --just half the power the Silvia draws. An invertor is totally out of the question, as the battery would need to supply almost 100 amps to it (for 1 hour). No lead-acid battery can be totally discharged, or even half discharged, so for ONE solitary espresso session including warm-up, you would need several expensive deep cycle batteries. In turn, these would then have to be re-charged from their depleted state. The boat alternator is incapable of doing that ---and of course, theres no 240V for a battery charger, and no charger is capable of that capacity anyway.

Not to mention having power cables to the inverter the size of jumper leads and then some.

The only answer is a very heavy, bigger capacity generator, or something like the lighter-weight Honda 4-stroke, 2KVA, which costs around $2000.

That works out at an expensive coffee, folks.

Robusto

Hope you are like me and Frugal/ Paid $98 bucks Oz for mine and they are now $168 at BunningsUsed It ma Couple of times already and it Starts and runs.. Should have purchased 5 at that price, had the readies..
We Have one VAN running around Coffs at this Time"Expresso"
Black Mitsubishi Van IIRC Ill try to track him down and find out what he has and Uses!

Tepin

[TEPIN]

Re: Coffee Vans

Some Great Info there , Have a Mate who is starting the 4wd Caravan Thing and saome of this Info will be of interest to hi, Lent him my Sodering Iron and the old Primus Kit (seperate Entities) so that he can Solder His Wires up under Van..
He Is a Retirred Marine Engineer With a Lathe so I look after him as Best I Can..
He Also did Work For Breweries and Chicken Processing Plants (Consultant) and He keeps My Handguns tuned for me, I just have to do my bit which lately has become harder due to old age and failing Eyesght , and premature Ejaculation of Bullets..
Tepin

[Javaphile]

Re: Coffee Vans

Another option Ive seen is to use a gas fired boiler and hot water heater along with a Cold Plate fridge which would eliminate the biggest electrical draws allowing you to then go with the inverter set-up to power the remaining devices.

Cold Plate fridges are commonly found on sailboats and ice cream trucks and basicly work by cooling a large chunk of metal which then acts as a heatsink to keep the fridge cool while it is disconnected from the power. They are commonly hooked up to the vehicles DC power so they can have their chill topped off while driving between locations or as needed on site.

Java "Chilling out" phile

[robusto]

Re: Coffee Vans

There are also eutectic fridges, in which a compressor freezes liquid in the insulation. The frozen liquid absorbs heat from the food and drinks until it thaws and then the compressor comes into play again.

We are more than happy with our 3-way fridge: 240v, 12V, and LPG. It uses around 100 grams of gas a day, if that, so a 3 kg bottle lasts and lasts.

But getting back to coffee machines where theres no mains power. The biggest power consumption by far is for heating. There should be some machine where pre-heated water (from the LPG stove) can be dumped into it. The next requirement for power is for the pump. Well, thats a trifling draw of .02 amps for the 25-seconds pull (3 amps in one hour). And a lever method would obviate the need for a pump anyway.

Perhaps those camping accessory shops should move up a notch in class and come up with such a machine for us who like our coffee take-away.

Robusto

[robman]

Re: Coffee Vans

Hi Team, great responses, thank you.

I think from the above info a generator would be the way to go. I guess you would not be able to drive about with the espresso machine going as the water would slosh about and maybe bare the element and stuff it.

Is the generator in a separate silenced compartment in this vans that were mentioned. Is there a particular brand of generators that are extra quiet.

Sorry about all the questions, although the forums are great for getting answeres.


regards Rob