Hi Steve,
Well its been covered many many times before!...
Its a mine feild to what to choose?
You say your are adding this as an additional service. Well firstly do you have any window cleaning clients?
If not I would stick to traditional methods first. But by all means take the plunge with wfp.
So lets say you want to plunge in, how many customers do you have, how fast are you growing as to the kit you can have a trolly system! Or a van mounted system. Vam nounted systems are great in one aspect but I have found that sometimes you cant get the vehicle close enough and require a trolley.
You will just about get a system with £1000 but it will only be an entry system. But good enough.
XLINE systems they are great I cant recomend them enough.
There are many others, the most famous I guess is pure freedom, I hear its a good trolley but for me it was not large enough as it held 20 - 25 litre jerry cans.
Now its not just a trolley that you will need, you will need a pole. This can be expensive but to start get around a 30 foot pole, a cheap one around £200 mark.. Yes they are not the lightest to use. When you get more work then get a better pole. Alighter one. Then we are talking money... lets face it its just a pole with a brush. Actually i think they poles are a complete rip off. No matter how lite they are.
So you have your trolley and pole, asuming thats the way forward you need an IBC tank, to store water. 1000 litre tnk is sufice.
But now to your RO Unit.
some use a small RO unit like merlin, or RO - MAN well if they are happy with that, thats fine and I am not putting anyone down who has them. But the amount of water they make is apalling! Its no where near enough. It takes ages. But if thats what you want go to
www.ro-man.com or just look on the web for RO units
They are around £250 - 350, if you are in a hard water area then you will need a water softener as well, and a DI chamber + DI resin.
But be warned they are slow in production. A larger RO unit will produce more but will cost a lot more.
I have a 40/40 RO and with the right presure can produce around 1000 litres in 4 hours or so.
almost forgot, you need a TDS mitre around £15.00 to let you know if the water is pure. That what the ro does. Your readings should be between 000 or 001 but many have higher reading ans still get good results.. but I wont take the chance!
Hope this helps
If you require any help if I can I will.
Dave