RO question (temperature vs pressure)

[mark]

So I figured go buy 50' of 1/4" tubing to use between water line and ro/di unit placing the excess as a loop in the sump. The unit would have a little better rejection ratio because of the warmer input temperature and I would get a cooling coil in the sump.

Just temporarily hooking stuff up see my input pressure has dropped quite a bit to 40psi.

Before I start doing comparisons a rejection ratios, wondering if it's even worth it considering the input pressure drop (in the red on the gauge). Those doing this, did you use large tubing for the sump loop?

Pressure gauge is T'eed just before prefilters.
RO/DI off, line pressure is 55psi.
Unit output open, short feed, input pressure 48psi.
Unit output open, 25' insert, input pressure 43psi.
Unit output open, 50' inset, input pressure 40psi.

[Delphinus]

43 seems pretty low to me, for that matter I think even 55 seems low. Do you have a pressure regulator on your house? I have one on mine that dials it down to 50psi so I tapped my RO/DI to just before the regulator and it runs from anywhere from 76 to 90 nowadays (much much better performance).

Over a 50' length I think I'd want to go minimum 3/8" line.

Neat idea though. Would be interested to hear the results.

[mark]

Thought you had the fix there (tap before the regulator) but just checked and my meter is after the regulator. Not that I'm planning on having the City over but sure they would frown on me tapping in before the meter. Wonder though if I could swap the meter and the reg?

I might just adjust the regulator up to 60psi but thinking I'm going to need to check into max PSI of a few things first.

[Delphinus]

Free water for your RO/DI!! Heh, sucks being honest somedays..

I wonder how hard it would be to swap them. Might be worth looking into, go to Home Depot and rent some crimpers ... hard call.

I found the only thing that mattered what I had the reg set at were the showers. I first tried opening up the reg all the way, and then suddenly showers hurt! So I dialed it back down. I wish I had put my outside lines before the reg because I've found I can't run two of those impulse type sprinklers simultaneously like I could at my old house (not enough pressure to run the bish-bish-bish part .. just sorta sit there with a pathetic little stream not turning or anything).. .. Anyhow other than the showers I'm not sure what really benefits from having the pressure dialed down.

[StirCrazy]

Originally Posted by mark

Thought you had the fix there (tap before the regulator) but just checked and my meter is after the regulator. Not that I'm planning on having the City over but sure they would frown on me tapping in before the meter. Wonder though if I could swap the meter and the reg?

I might just adjust the regulator up to 60psi but thinking I'm going to need to check into max PSI of a few things first.

should be able to go to 90ish no problem at all. as far as shaowers are concerned, don't open the tap as much .

Steve

[Delphinus]

Originally Posted by StirCrazy

as far as shaowers are concerned, don't open the tap as much .

Yeah, except that my showers (and baths for that matter) are the type that are on or off, you can only adjust the temperature but not the flowrate. If you have the style where you can adjust the flow then yes you're set. Wasn't an option for me; but really, cutting that pex stuff and recrimping new ends is a 5 minute job once you have the crimper tool so that's not a big deal either..

(PS/Edit. I suppose that doesn't hold true if you have copper pipes or something.. so I guess it depends still.. Ooops.)

[G1GY]

Originally Posted by Delphinus

(PS/Edit. I suppose that doesn't hold true if you have copper pipes or something.. so I guess it depends still.. Ooops.)

If you have copper pipe, there's a good chance that your house was built way before they started putting regulators in.