40 psi is the recommended minimum for a merlin, any lower and there will be more waste water than usual.but if he isnt worried about the waste (which is minute compared to the millions of gallons leaking from the water boards pipes around the country!)then a merlin is far simpler. How far will the merlin be from the water supply? the further it travels down a garden hose the greater the resistance and therefore the pressure going into the merlin will be less than the pressure leaving the kitchen tap.clear as mud so far, but ime going to lie down now. 8)Syd
He will have a booster pump fitted and his tap is around 15' away from where the system will be set up.
Looking at all the replies I have had regarding the merlin, it does look like his best option, especially for the expansion side of things.
Hi Jeff, just thought i say what my merlin is giving me at the mo... At 54 psi it produces 1.2 ltr a min at 30 tds. Waste is 4 ltr a min. Tap tds in is 221 and waste around 300. I have the out put from the Merlin running through a very small DI which came with my ro-man. Found the ro-man was really slow could have added more pre filters but decided to go for quantity. Over all in your friends situation Merlin should be faster overall but i think the tds would be higher and you will need to di the water as it is stored or at point of use. poss both!
As andrew said not much in it and get the right pump they are not cheap as you may know.
Spend a bit more on bits and bobs too quality parts last soo much longer, plastic connectors break quite easily.
Good luck
Regards
Paul
Thanks Paul
He will have a booster pump and I see the quote includes a full 4.6ltr DI vessel.
I have now emailed him as I still can't get through on the phone, I have suggested he takes the quote he has had.
He's had a very good price from James of X-line with a very good list of parts.