i know that for an RO/Di to work optimally you want room temp water going into it but i have a problem that my water coming in during winter is very cold not sure exact temp, but not warm. Would I be ok to run it with this water during the winter or is there some sort of solution to this problem, or is there a different type of membrane that works better for cold water?
RO-DI with cold water
- Thread starter rrodd89
- Start date
Ebmorri
New member
I had to mixer valve by tapping both hot and cold water, run each one to a T and then the other opening to my RO/DI unit. My cold water temp was 55 degrees and that was before the current cold snap we are having. Just make sure you do not allow to much hot water through your RO/DI or you will burn up your cartridges. I tried the Melev option but there was no way to bring the temp up that much without using 100+ foot of hose.
Erick
Erick
frank2926
Active member
those methods work but at a much bigger cost than a booster pump. If your pressure is over 60psi I dont think you really need to worry about the cold water to a point. and if you mix in hot water you will need to change your sediment more often. Not that thats expensive but if it gets clogged it will decrease pressure enough to cancel out using warm water. There is a ton of sediment buildup in most hot water tanks.
RandyStacyE
New member
I've been running cold water through my RO/DI unit for years. I'm sure that the 'optimal performance' of the membrane is stated using water at a specific temp, but I never was concerned enough to do anything about it.
An in-line preheater sounds nice ... I'd say that 99.9% of RO/DI owners just tap off of their cold water line.
I believe most all tap water is somewhere around 55-60 degrees in most parts of the US regardless of the season. I suppose the question here is "is it worth it"?
Don't get me wrong ... I've pondered on the idea many times and If I knew of an excellent DIY inline preheater, I'd probably try it sometime.
An in-line preheater sounds nice ... I'd say that 99.9% of RO/DI owners just tap off of their cold water line.
I believe most all tap water is somewhere around 55-60 degrees in most parts of the US regardless of the season. I suppose the question here is "is it worth it"?
Don't get me wrong ... I've pondered on the idea many times and If I knew of an excellent DIY inline preheater, I'd probably try it sometime.
BeanAnimal
Premium Member
Heating the water will cost more than the extra waste produced by the cold water.
AZDesertRat
In Memoriam
I am using a 90 GPD Spectrapure MaxCap RO/DI which uses a hand tested version of the Dow Filmtec 75 GPD RO membrane. Last night I made 30 gallons of water, my incoming pressure was 68, pressure after the prefilter and 0.5 micron carbon block was 64, water temperature was 60.2 F. and I was making water at a rate of 62 GPD with a 4:1 waste ratio.
Temperature makes a big difference but if your pressure is good it helps as membranes are rated at 50 psi and 77 degrees F.
Look here at Dows charts and you see how both temp and pressure affect output:
http://www.dow.com/PublishedLiterat...seps/pdfs/noreg/609-09010.pdf&fromPage=GetDoc
Using their charts my pressure puts my output up to about 100 GPD but the temperature knocks it back to just over 50 GPD so I figure I am right in line where it should be.
Temperature makes a big difference but if your pressure is good it helps as membranes are rated at 50 psi and 77 degrees F.
Look here at Dows charts and you see how both temp and pressure affect output:
http://www.dow.com/PublishedLiterat...seps/pdfs/noreg/609-09010.pdf&fromPage=GetDoc
Using their charts my pressure puts my output up to about 100 GPD but the temperature knocks it back to just over 50 GPD so I figure I am right in line where it should be.
AZDesertRat
In Memoriam
No. its a little high but still OK. Most all plumbing fixtures are rated at 125 psi even though most water pressure is in the 50 to 60 psi range and rarely exceeds 80. The city I used to work fo had lots of areas that exceeded 100 psi and most people did not have pressure regulators and were fine.
tgunn
Active member
Another option which another reefer showed me is to coil up around 100ft of RO/DI tubing and drop it into the sump. I run the water from the carbon and sediments canisters through that before hitting the membrane. It's warmed up quite a bit before it hits the membrane. This helps with the tank temps too..
Tyler
Tyler
AZDesertRat
In Memoriam
Lots of vendors now sell units with dual membranes specifically for cold water applications, I know Spectrapure is one.
