RODI in cold weather

[ZaneGreay]

So I live in the Midwest and it's pretty cold right now, I also have a well on my property that provides me water. Now I have read the RODI system doesn't work to well in colder weather. So what can I do? My cold water is exactly that cold lol average between 50* to 57* on average depending on how long it's been sitting in the line in the house. So what can I do to get more life out of my system?

 

[Dave Bayliss]

Ive thought of the same thing for a while, im on a well, in the mid east water us around 45-50 f in the cold months, do I simply run a coil around 30ft prior to the unit to get some heat into the water??

 

[ZaneGreay]

Ive thought of the same thing for a while, im on a well, in the mid east water us around 45-50 f in the cold months, do I simply run a coil around 30ft prior to the unit to get some heat into the water??

I don't believe that would work the water won't be in the house long enough to bring it up to temp unless your house is hot.

 

[Dave Bayliss]

I don't believe that would work the water won't be in the house long enough to bring it up to temp unless your house is hot.

30 ft os 1./4" ro pipework may bring it up to at least 60 f if you keep your house at 65/ 70f, however i may be talking out of my rectum......

 

[Phyber]

Seems to be the opposite of what I read regarding temp...a cooler water temp would.make it easier on your RO unit if I'm remembering BRS TV correctly...

DOW specs their GPD based on certain parameters, one of them being 70* incoming water.

 

[ZaneGreay]

Seems to be the opposite of what I read regarding temp...a cooler water temp would.make it easier on your RO unit if I'm remembering BRS TV correctly...

DOW specs their GPD based on certain parameters, one of them being 70* incoming water.

Well when I googled it two seconds ago lol it says that most rodi systems work best around 70* water. I was worried I got tricked to try to sell me a different rodi system lol

 

[Phyber]

Well when I googled it two seconds ago lol it says that most rodi systems work best around 70* water. I was worried I got tricked to try to sell me a different rodi system lol

I think the only bad water temp is hot, like accidentally turning on the hot water handle instead of cold if you hook up to the faucet like I do. Hot water will degrade the RO membrane severely.

 

[KrisReef]

I don't know the answer to the OP's question, it is very interesting.

Thank for posting this timely question @ZaneGreay. My RO system is running and I forgot about it until just now. I hope I don't need galoshes.

 

[Brian_68]

For me cold incoming temps give me less of the RO water and more waste water. More gets rejected.

 

[ZaneGreay]

For me cold incoming temps give me less of the RO water and more waste water. More gets rejected.

That's exactly the problem I am having I'm supposed to have 100gpd system and yet I barley made 20g the other day leaving it on over night when I should have made at least 40 giving it about 8-10hrs don't remember exactly when I started it before bed but I slept in and everything. freaked when I was laying in bed goofing around online and remembered it was running. Expected to see my 50g barrel about to overflow but it was barley at half which shocked me since I had some water in it before I started it.

 

[DangerDave]

What is the pressure of the water going into the filter?

 

[HuneyBear]

I know it may or may not help you but here is a calculator for RODI output that includes temperature. http://www.buckeyehydro.com/calculator/
You would have to know water pressure for it though.

 

[DCR]

The pressure drop across the membrane is going to be a lot higher with cold water (mainly due to viscosity I think) which reduces the product water flow. The reduction in water flow makes sense technically.

 

[MERKEY]

I know it may or may not help you but here is a calculator for RODI output that includes temperature. http://www.buckeyehydro.com/calculator/
You would have to know water pressure for it though.

This is a cool chart/calculator but I ran into this issue.

I have a 75gpd 7 stage and to get a calculation of 77gpd I need a temp of 131f or 55c.....that seems crazy. What am I missing or am I using this wrong lol this calculator would suggest hotter temps get more gpd.

As my water is now it comes in at 40f or 5c and according to the calculator that only gives me 25gpd.

However as my ro unit produces now it takes me 2 hours to fill a 5 gallon jug. So I'm actually getting 60gpd at 75psi and at a degrees of 40f or 5c.

So either I'm messing up which is probably right or the chart is off. I put my money on me messing something up haha

 

[Idoc]

My RODI production always drops drastically in the winter with lower temp water.

 

[HuneyBear]

This is a cool chart/calculator but I ran into this issue.

I have a 75gpd 7 stage and to get a calculation of 77gpd I need a temp of 131f or 55c.....that seems crazy. What am I missing or am I using this wrong lol this calculator would suggest hotter temps get more gpd.

As my water is now it comes in at 40f or 5c and according to the calculator that only gives me 25gpd.

However as my ro unit produces now it takes me 2 hours to fill a 5 gallon jug. So I'm actually getting 60gpd at 75psi and at a degrees of 40f or 5c.

So either I'm messing up which is probably right or the chart is off. I put my money on me messing something up haha

You do not run hot water through a RODI unit no matter what any chart says I know that. Hot water will destroy a membrane.

 

[Daddy-o]

My RODI is outside getting feed water from a spiqot. Last year I thought that my decrease in production was caused by low temps. Then a buddy suggested changing the sediment filter, removing the first carbon filter and putting the second carbon in its place and adding a new carbon filter to the number 2 carbon chamber - worked like a champ!
Cheers! Mark

 

[MERKEY]

You do not run hot water through a RODI unit no matter what any chart says I know that. Hot water will destroy a membrane.

That's kinda my point... this calculator cant be good to use.

 

[HuneyBear]

That's kinda my point... this calculator cant be good to use.

It’s an estimating calculator based on new clean equipment. Results are going to always vary based on life of ones filters and what’s in your water. It’s pretty accurate for me but I’m on a water system that Is ridiculously clean coming from the tap.

 

[Randy Holmes-Farley Verified Community Expert]

FYI, water flow slows down due to the viscosity increase of water at lower temps, slowing it down going through the tiny passages of the ro membrane. The water you get, however, is just as good.