Pre-heating RODI water

[dmolavi]

I just picked up a BRS 5 stage plus RODI unit. According to the specs, it performs best with water at about 77F. Right now, my tap is frigid, so I was going to run a coil of 20ft of copper tubing through a 5 gallon bucket with a heater set to 78-ish. Is 20ft long enough to bring the water up to (or closer to) temp? Too long?

 

[San Raphael Catfish]

Wow. I am not that good. I would run it plumbed directly into the frigid cold water. And forget about optimal and say it is better than not using it.

Weird that kind of temperature would be easier to hit with a portable set up coming out of a faucet mixing hot and cold. But I have always heard the hot is worse to metals.

SRC

 

[mr_X]

I agree with SRC- don't bother.

 

[San Raphael Catfish]

BRS has RODI video on YouTube and I don't remember 1 mention of the importance of operating temperature.

SRC

 

[Sniperhank]

The only thing I remember about everything regarding RO/DI is to not use hot water as it will use up the membrane or resin faster than normal...don't recall which. I just turn the cold tap on and start producing water.

 

[dmolavi]

BRS has RODI video on YouTube and I don't remember 1 mention of the importance of operating temperature.

SRC

This is on their site (Questions on BRS 5 Stage PLUS RO/DI System - 75GPD - Bulk Reef Supply ):

by Rhi on March 21, 2012, @10:54 AM

The answer to the previous question re: waste water ratio referred briefly to correct water temp. We have well water and it comes into the house very cold, my current RO unit almost floods the room due to the condensation dripping from it. Do you have any recommendations for heating the water to the appropriate temperature? Thereby improving waste water usage and helping with condensation issues.

Bulk Reef Supply
Hey Rhi,
The membranes themselves are rated at 50psi and 77F water. You can expect about a 2% decrease in production for every degree lower you are.

Most people find that its cheaper to just use the extra water than to heat it, but if you wanted to heat it the easiest thing to do is to coil a bunch of tubing up inside of a bucket (preferably thin copper tubing as it conducts heat well). You fill the bucket up with water, put a heater in to keep the water warm. As the water passes through the tube in the bucket is absorbs the heat and warms the water going into the ro unit.

I think I'm going to try to be a good citizen here and raise the temp, esp if a 20 degree drop would equate to a 40% production drop.

 

[Nosaj81]

i have never heard of anyone heating the water for the ro/di system plumb right from cold tap and thats it

 

[San Raphael Catfish]

Weird. I thought if possible we were trying also to avoid copper pipes. I don't which is worse new or old copper pipes. But it is on the supply side. Does your cold water supply change temperature with the season? Ours does here.

SRC

 

[Phranque]

Weird. I thought if possible we were trying also to avoid copper pipes. I don't which is worse new or old copper pipes. But it is on the supply side. Does your cold water supply change temperature with the season? Ours does here.

SRC

The copper pipe would be on the pre-membrane side, so the membrane & DI would remove any contamination..... wouldn't be any different than the water from the pipes.

 

[mr_X]

How do you plan to heat the water? Use the hot side? I think I would rather lose 40% than run my water heater as long....

 

[dmolavi]

How do you plan to heat the water? Use the hot side? I think I would rather lose 40% than run my water heater as long....

Run it through copper coil submerged in a 5 gallon bucket filled with water and a spare heater.

 

[mr_X]

Let us know how that turns out.

 

[JonathanG]

I use a shower to supply my water and the regulator for the shower is the single knob type where the more you turn it the warmer it gets. I have noticed a slight increase in production when using warmer water, but it is very slight.

 

[Keithhjs]

The extra energy required to heat the incoming water is probably more wasteful then just running your RODI straight from the cold water supply line. That 2% statistic per 1 degree is probably not exact either. I have my unit in the garage inside a cabinet and sometimes the garage door is open to the winter cold all night and I don't see that much drop off on my product water. Also as mentioned before it doesn't matter whether you have galvanized, PVC, PB, ,pex, copper, etc for your water piping because the filter removes the impurities and particulates.