I opted for machines that can run from 20 - 40LPM as site, water and cleaning dictated, which to me is even more efficient than the below statement but I do take into account the 'members' smaller requirements.
Not sure how the 'more sqm of cleaning per litre of water' statement would hold out on side by side tests but as with Smurf who didn't want to partake in my invite to see equipment Scott was invited to come and meet me when I worked on his local Sainsbury's but either didn't turn up or skulked in the car park watching.
All of the above/below may be different if 'efficent' is a newly added word to the English language and isn't 'efficient' spelt wrongly.
Your 21lpm machine will run at about 170bar.
We opted for more efficent machines (more sqm of cleaning per litre of water). We run 250/60 bar machines at 20lpm .
Water is always an issue. Unless you wish to start filling tanks from hydrants. Something I prefer not to do.Last night I did an 'evening' shift @ Ikea - Ashton under Lyne, started @ 6ish with poor supply filling up with water in the service yard.
Started on the clean down @ 19.20. Filled the tank to 1400 litres and kept the flow at about 25 LPM.
Finished at 21.00 hrs. No need to refill or 'travel' to get more water. The set up made this really difficult so a survey beforehand made decisions easier, though live sites change and a van sat over the hydrant/WO won't allow its use.
I've got through Aquam - as Charlie has said two Severn Trent fire hydrants, which I believe is Manchester's water provider and despite there being a hydrant every ten metres on site not possible last night.
