RO System to go into Van

[aaronmck]

Hi all, I am in the market to buy an RO system to make my own water as I currently use Spotless Water to fill my 500L tank.

I don't mind spending the money on something that will be worth it in the long run and will last or make life easier. I will need to fill up to 500L each day after work. I have been looking at the 4040 vs 4021 and HF4 vs HF5. I live in the West Midlands and TDS is currently around 140 but I'm sure was higher before when I first moved into the house (used to live in a flat).
My pressure is just over 50 PSI.

My understanding is the 4040 vs 4021 is just related to the size of the membrane the amount of water it can produce and potentially the speed at which the water can be made. with 50PSI I was leaning towards a HF5 membrane but having just called and spoken to the cleaning warehouse in Willenhall he said that the manufacturers recommend 100PSI for HF4 and 80PSI for HF5 membranes. So you will void the warranty if using less pressure. I was worried about less pressure causing the life span of the membrane to be reduced and he said it doesn't affect it too much but I've read otherwise. He said HF4 is cheaper than HF5 and because I'd have less than the pressure of both of the recommended values of the manufacturer's id be better off going the HF4 route and putting any saving towards a booster pump..

What do you think? Ideally, i'd go without a booster pump as I see they're a bit pricey but if needed, that's fine. Also what about features such as flushing the membranes? Can that be done manually on all of them?

Been looking at

Water Genie - The BIG Genie Static RO 4040 Professional system

Size Height - 105cm length of panel- 66cm length at RO - 125cm The Big Genie Includes 2 x 20 Pre Filter Housings 40 Low pressure RO membrane and

www.thecleaningwarehouse.co.uk

I like this one cause it will bolt to the frame I have as it's from the same place but not sure the guy has given me sound advice as other sites such as xline say some of their systems need 60 PSI else RO membrane could become damaged for example this one 2,000 GPD Static Manual Pure Water R/O System - Wall Mounted

Is it better to take pure from RO to tank and then DI to pole or would you recommend that I RO pure into DI then to tank and then just deliver to pole?

Thanks in advance for your help
Aaron

 

[ched999uk]

Too high a pressure (within limits Max normally about 300psi) is not a problem for most of us.
Flushing requires a valve to be opened to allow full flow (booster pump off). Some people use a 'standard' gate valve with a small hole drilled in so it can be closed and still allow the correct water flow. To be efficient the flow through the membrane has to be restricted to increase the pressure in the membrane layers, so you have to have a valve on the waste outlet to restrict but never cut off the flow.

The best person to speak to is @doug atkinson at DAqua.co.uk he will advise you on the best kit and not oversell stuff that you don't need.

As for DI before or after tank it sort of depends. On the one hand before the tank means you can have more flow to your brush and can fill a backpack directly from your tank (tank will be at 0tds) quickly if needed. On the other having DI after the tank means that in an emergency you could fill your tank with tap water and have the DI take it down to pure although this might be expensive for resin but it could get you out of a fix or allow bigger jobs?

 

[spruce]

My experience has been very positive using an axeon hf5 membrane at 50 psi tap water pressure. My membrane is over 10 years old and still producing at 97% rejection rate. Our tap water TDs is around 130ppm. When processing water my waste to pure ratio is around 55 waste to 45 pure.
I have never heard of the membrane's warranty being affected by using a lower water pressure than 80psi. That's a new one on me.

Be careful about suppliers claiming to sell a low pressure membrane. One supplier advertisers a low pressure membrane, but the specs show the membrane needs 125psi of water pressure applied to it.
A blue water sailing boat with a water maker on board needs a 600psi water pressure applied to the membrane. In comparison, 125psi is low pressure I guess.

Yes the price of an axeon hf5 membrane is crazy, but they are the only true low pressure membrane on the market.

When using an onboard r/o unit, most suppliers supply a 4040. At 50 psi I get roughly 2 litres of pure every minute. A 4021 will do half that.

If going the onboard route I would recommend fitting a float switch to cut water to the r/o when the tank is full. Purefreedom fit a float switch as standard on their onboard r/o systems. It saves flooding your van out.

I also recommend fitting 2 x 20" prefilters. The first one is a sediment filter and I recommend you go for one with a clear bowl so you can monitor the state of the sediment filter visually.

 

[Part Timer]

If you have the room to do it out of the van, garage, shed etc, then it is far cheaper, both in initial costs and ongoing costs, to do it this way.

 

[Iron Giant]

Wall mounted is fine if you are able to securely mount it to the wall of your garage as otherwise, you are paying extra for the pre-fab frame, what you need to consider is where is your waste water going to because ideally it needs to go down a drain or if suitable onto your garden or even a water butt to water your garden through the summer how are you going to get the waste pipe through the garage wall and to the drain or whatever, As you will be disposing of well over 500ltrs of waste water a day so it needs thinking about as it's a lot of water day after day.

Have you got the space for a 1000ltr ibc these are usually fairly cheap to buy so most opt for that size I personally went for a 550ltr Endurmax slimline tank with a 45cm lid to drop the sub pump in without the need to be cutting a tank up.

 

[aaronmck]

Thank you for your replies, I do have a shed on a decent concrete pad which could potentially take a 1000L tank but as mentioned above, I'm not entirely sure where I would drain the waste. I do have a storm drain at the end of my driveway so I was thinking of using that for waste if making pure in the van. I could potentially run a waste hose to the same drain, it's about a 15M run. But both my outside tap and storm drain are near the front of my house as the kitchen is at the front of the house and was the only place I could put the tap without loads of faf. The shed is at the back of the garden. So would need to run several hoses.

When you say the costs come down by making pure in a shed or garage is it mainly down to not having to make pure so quickly that contributes to cutting the costs? i.e smaller membrane and filters? Would I need to insulate the shed for those frosty winter nights to protect the membrane etc?

 

[spruce]

Also important to consider with a van mount is that the r/o needs to be protected against frost during the winter, which also applies to an r/o mounted on the wall in the garage. @aaronmck

 

[spruce]

Thank you for your replies, I do have a shed on a decent concrete pad which could potentially take a 1000L tank but as mentioned above, I'm not entirely sure where I would drain the waste. I do have a storm drain at the end of my driveway so I was thinking of using that for waste if making pure in the van. I could potentially run a waste hose to the same drain, it's about a 15M run. But both my outside tap and storm drain are near the front of my house as the kitchen is at the front of the house and was the only place I could put the tap without loads of faf. The shed is at the back of the garden. So would need to run several hoses.

When you say the costs come down by making pure in a shed or garage is it mainly down to not having to make pure so quickly that contributes to cutting the costs? i.e smaller membrane and filters? Would I need to insulate the shed for those frosty winter nights to protect the membrane etc?

I think you have to be very careful where you release waste water. If your kitchen is in the front of the house, you will be able to put a hose into that sewer drain. Most people (especially neighbours) have no idea how an r/o works. Keep it that way.

Even if you are on a water meter and pay for that water going to waste, wasting water is a very emotional subject, especially if you are in an area with a hose pipe ban. Our waste water goes into the back sewer and nobody knows about it. All they see is me filling my van in the morning.They know I filter water during the day, but it is all quite. I don't want a noisy booster pump, for example, drawing unwanted attention to my business.

The efficiency of your membrane is very important to cost saving.
There was another window cleaner on the estate opposite ours. He processed water with a Merlin r/o, well know for being inefficient as it wasn't designed for window cleaning. His rejection rate was around 90% where my 4040 was 98% at the time. Our tap water TDs was around the 130ppm and his resin costs were nearly 4 times what mine was.

Producing water at home will be cheaper and more convenient than buying it, hence cost saving. But you also have to maintain your r/o changing prefilters timeously.

 

[Part Timer]

To produce pure in a van you really need to produce 150l+ an hour. To produce at home 50l an hour is plentiful. You also don't need to carry R/O, Di, booster pump etc in the van so fuel economy will be better

 

[Iron Giant]

Thank you for your replies, I do have a shed on a decent concrete pad which could potentially take a 1000L tank but as mentioned above, I'm not entirely sure where I would drain the waste. I do have a storm drain at the end of my driveway so I was thinking of using that for waste if making pure in the van. I could potentially run a waste hose to the same drain, it's about a 15M run. But both my outside tap and storm drain are near the front of my house as the kitchen is at the front of the house and was the only place I could put the tap without loads of faf. The shed is at the back of the garden. So would need to run several hoses.

When you say the costs come down by making pure in a shed or garage is it mainly down to not having to make pure so quickly that contributes to cutting the costs? i.e smaller membrane and filters? Would I need to insulate the shed for those frosty winter nights to protect the membrane etc?

How long is your garden to need several hoses

You will need to insulate your shed to protect your R/O and anything else in there also those several hoses will need draining on cold nights, also best to ensure your she has a good preservative on the floor as it's inevitable water will get spilt at some point

 

[spruce]

With an on board r/o you only have the water available you produce that day. Mind you, it's exactly the same buying in water.
500 litres a day should be enough for most single window cleaners. If you did need more, then you could always top up from Spotless.

I maybe wrong but it would question whether a shed floor would support a ton plus weight of water. I know of one person who cut the floor out the size of the base of the ibc tank, and 'poured' a concrete base to sit the ibc tank on.