Ro/di water... Use hot or cold water.......

[casualreefer]

I was just wondering which people use when making water hot or cold water. I've always used warm water but I just read something about using cold water is better for some reason. Any info or opinions are welcome.

[SlowCobra]

Hot water destroys the membrane.

[casualreefer]

In the three years I've been in three years I've been in the hobby I've never heard that. Ya learn something new everyday.

[RandalB]

Yep, anything over 113-115F will melt the glue and material that the membrane is made of and destroy it.

RandalB

[saleenpwr88]

Maybe hot water ruins it, don't know about that or why you would even use hot water, but warm water will make it most efficient. I think around 78 degrees but I'm not positive about the exact degress.

[SlowCobra]

If you are using a sink adapter then it is easy to get warm water however those of us that install a saddle valve have 2 choices... cold or hot.

[casualreefer]

i've never used HOT water, usually i turn the hot and cold on all the way. i read that using cold water will help filter out more stuff than using warm water. is there any truth to that?

[RandalB]

Originally posted by saleenpwr88
Maybe hot water ruins it, don't know about that or why you would even use hot water, but warm water will make it most efficient. I think around 78 degrees but I'm not positive about the exact degress.

Actually it gets more efficient the hotter the feed water (right up until the membrane melts..)

Here's a thread that explains it: http://forum.simplydiscus.com//showthread.php?t=34285

There's also a formula to figure out your RO unit GPD with your params.

HTH,
RandalB

[Pufferpunk]

Such a total waste of hot water down the drain.

[RandalB]

I agree, booster pumps work much better for increasing RO efficiency...

RandalB

[121a]

yeah, hot water works great. I had mine out in a 3 season room, with a hot tub. I ran a garden hose, which i put into the 102-103F hot tub, and it actually got the tap water from the spigot to 80 or higher, i noticed much more water production.

[coralcenter]

for me,i uesd cold water it does not how cold is it
hot water i think not good for the membrain

[wld1783]

I have two saddle valves, a T and use warm water. If I did not my dual 120GPD is a 20GPD in winter.

Bill

29 are spouse beaters, 7 convicted of fraud, 19 have bounced checks, 3 spent time for assault, 71 have bad credit, 14 busted for smoking dope, 8 arrested for shoplifting, 21 are defendants in lawsuits, and 84 have been arrested for DUI in one year…Your US Congress…
I thought I’d run someday but I’m unqualified as I don’t have a felony conviction on my record.

[Brian1980]

by using hot water you use up your filters quicker since sediment and calcim buildup is inside your hot water tank. which causes your filter to have to work even harder if the water temp is about 78 degrees and you have good pressure it will be as efficent as possible.

[Pufferpunk]

Originally posted by wld1783
I have two saddle valves, a T and use warm water. If I did not my dual 120GPD is a 20GPD in winter.

Hmmm... is thay why it takes longer to make water now? Hubby said he'd kill me if he sees the hot water on when I'm making RODI.

[wmilas]

If you mix hot and cold, even with saddle valves you could have another problem. Unless the water pressure is COMPLETELY balance between the hot and cold line, you will push the higher pressure (almost always cold) into the hot water line. This can do serious damage to your hot water heater. In a residential house this is typically not much of a problem. In a condo or a apartment you could have serious issues.

Its against code to mix pressurized pipes without having a de-pressurized release.

This aside its silly to use hot water. As stated above a booster pump is far more effective with less calcification, ect.

[MGM_]

A mixer valve with scald guard would be the best way to mix the hot/cold to obtain an 80 F mix. The scald guard is important as it prevents temperature bursts and overheating the RO membrane (think toilet flushed while showering). Hot/cold mixing is a cheap means for increasing efficiency. A permeate pump is of no use if you are using an open system (no pressurized storage tank). As far as cold water back up into the water heater the mixer valve will control this issue.

NOTE: Permeate pump is not same as booster pump. Booster can increase efficiency in low pressure conditions (well water applications) and will increase efficiency in an open system.

[badazztealcobra]

Originally Posted by MGM_

A mixer valve with scald guard would be the best way to mix the hot/cold to obtain an 80 F mix. The scald guard is important as it prevents temperature bursts and overheating the RO membrane (think toilet flushed while showering). Hot/cold mixing is a cheap means for increasing efficiency. A permeate pump is of no use if you are using an open system (no pressurized storage tank). As far as cold water back up into the water heater the mixer valve will control this issue.

NOTE: Permeate pump is not same as booster pump. Booster can increase efficiency in low pressure conditions (well water applications) and will increase efficiency in an open system.

How far back did you have to look to find a post that was two years old ???

[jkf1983]

Any specific type of mixing valve? I found this solution below at melevsreef but it sounds like a mixing valve would probably be more efficient.

(look for the yellow text)
http://www.melevsreef.com/rodi_install.html

[skunkmere]

the colder the water the smaller the pores in the membrane and less effieciency, but cleaner water.

[paradox09]

Considering the piping on the hot water side of a system is usually more corroded . Especially galvanized and older systems. That we predominantly still use hot water tanks . That the run is longer from the service to the fixture on the hot side . I would assume
That the tds would be substantially more than the cold side. Thus more prefiltering . Has anyone checked the tds ?

[Jackie Blue]

I got two saddle's and plumed hot and cold into a T then ran it to the RODI, I let the water run and then adjust it so it's a little blow luke warm, that way if I forget to readjust it in the summer it won't destroy the membrane .

[MGM_]

Jackie.. The problem is you shut down the cold water side for any home maintenance you just cooked your membrane. Also shutting off your whole house water may allow some hot water bleed from the hot water tank. These things are considered by RO/DI manufacturers and is why the simply suggest cold water only. Proper set up can make mixing an effective means for increased efficiency vs potential risk.

[Blackhawk007]

Originally Posted by saleenpwr88

Maybe hot water ruins it, don't know about that or why you would even use hot water, but warm water will make it most efficient. I think around 78 degrees but I'm not positive about the exact degress.

In my apartment complex there is one hot water heater for all 100 units. The problem with this is when the flow rate changes the temp. For example turn my faucet on and get a good warm mix between hot and cold. Then when I switch it over to the R/O unit since its a slower flow the hot water turns almost completely off (imagine how showers are). This then decreases the flow through my R/O quite a bit because the water is so damn cold.

So my answer to the OP is warm, not cold or hot.

[Jeff]

Originally Posted by Blackhawk007

So my answer to the OP is warm, not cold or hot.

Look at the start date of this thread and the OP's status