RO/DI modification.

Discussion in 'DIY' started by sfsuphysics, Dec 7, 2005.

  1. sfsuphysics

    sfsuphysics Supporting Member

    Ok so I just bought 200 feet of 1/4" vinyl tubing, winter is here, it's getting quite a bit colder, so water pipes in the ground are colder, as a result RO units tend to be not as effective, so much in fact you might constantly be pouring waste water down the drain regardless of your water production.

    So what did I do with this tubing? well I ran it down into my basement out to my rock cooking vat (with a nice heater to keep it warm). The idea is hopefully this will warm the water up a bit before it gets to the filters so it'll more efficiently produce water.. and my water bill won't be skyrocket high at the end of the month.

    Now will this work? Hopefully :)

    Why didn't I just knock into the hotwater line? Well first the placement of my RO Unit is not set in stone, when the great tank move begins I'm going to put it downstairs near the tank so I won't need vinyl tubing running from my kitchen to fish room in the hallway. Second I've heard that you can get calcium buildups or something from your hot water heater's tank or something that can prematurely damage a membrane.

    Well we'll see how well it works :)
  2. Vincerama2

    Vincerama2 Evil Overlord

    As an idea, you could probably wrap the some of the tubing AROUND a hot water pipe as well as opposed to using a hotwater source. Sure, hot water pipes cool down (which is why you have to "run" it before you get hot water) but it would be almost "free". Or wrap it around a heating duct.

  3. GreshamH

    GreshamH Guest

    I enclose my RO/DI unit in a very good insulation (neopreme relative) and wrap my source water line around my bot water source which also is enclosed in the same insulation. IME it really makes a difference in the ratio.
  4. sfsuphysics

    sfsuphysics Supporting Member

    I dont know how comfortable I'd feel with wrapping vinyl tubing around copper pipes... it can get a bit warm. That and I really dont use that much hot water so I doubt it'd make much of a difference. I know after about 10 minutes I could easily feel the difference in the two lines, one which had the incoming water was MUCH cooler than the one coming back from the cooking vat.
  5. Mr. Ugly

    Mr. Ugly Past President

    Yah, heat exchange in the cooking vat is a good way. I saw another recommendation of setting that coil in a bucket of water with a heater.
  6. sfsuphysics

    sfsuphysics Supporting Member

    just exchange the word bucket with sump, and you're set :)
  7. Raddogz

    Raddogz Guest

  8. Vincerama2

    Vincerama2 Evil Overlord

    Yeah, I'd shove it through my sump if I could reach it! However, aren't we just replacing excessive water usage with extra electricity? I mean, if you run the intake water through a vat that you heat, aren't you just consuming another type or resource? Just wondering! (and being a pain).

    I'll bet that if you have access to the roof, you could get some good solar heating on the line! I'm not sure if you guys have holding tanks on your RO units, but mine has a tank that "caches" about 3 gallons. If you take water form the tank then the RO "turns on". So I can SORT OF control when the RO turns on, just by drawing water from the system into a 5 gallon bucket. If you do this in the morning, then the sun can warm up your line while the RO is working. (meaning that at night, the line might get too cold).

    Hmmm.... Now my DIY interest is piqued...

  9. sfsuphysics

    sfsuphysics Supporting Member

    Well yes, if you put it through your sump you'll be using electricity, but I doubt it'll be of a significant amount unless you run a lot of water through it. DIY chiller anyone?? :) But just wrapping it around the hot water pipes will only work if you happen to have hot water going through the pipes at the time you are making water.. which I doubt would happen very often. With my setup I'm using electricity anyways, I'm not really concerned about electricity usage.. my gas bill quadrupled though!

    I guess you could do a solar setup, but how much effort would you have to put through for what gain? You dont want the water TOO hot, and 80F is perfect, I think all data sheets show the production of the TFM at 77F.
  10. Elite

    Elite Guest

    So cold water is not good for RO/DI unit??
  11. Vincerama2

    Vincerama2 Evil Overlord

    I Dont' think that cold water is BAD for the RO, but I believe warmer water works BETTER. That probably results in lesswater being "rejected" by the membrane while still maintaining quality of the resulting "RO" water.

  12. Elite

    Elite Guest

    yeah that's what I meant :D ... Interesting.. I didn't know that. I guess I have to cover my RO unit somehow.
  13. sfsuphysics

    sfsuphysics Supporting Member

    well all the numbers they give you on a RO unit (membranes) are for ideal conditions, 77F & 50psi happens to be my unit.. now you could get more with higher PSI. With colder water you make less water. Also a few of the experts over at RC have mentioned more waste water as a result due to the density of the water.

    Its not BAD for the unit, but it is not as efficient.
  14. jimsar

    jimsar Guest

    Check out the flow restrictor/flush kit combo. I got one of these last year and it really helped.

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