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Pex led was supposed to be pex
Yes you can use pex but I can’t as I can’t fit enough pex in my sump to make the switch worth it
Heating large tanks with your gas hot water heater. Save 40% on energy cost!
Yes you can use pex but I can’t as I can’t fit enough pex in my sump to make the switch worth it
mrpizzaface
Well-Known Member
How have the titanium heat exchangers held up. I think I heard somewhere that @Terence had his fail, and ended up with pex in his sump. I would like to do this, but am afraid of ebay heat exchangers failing.
Blue Carbon Reefing
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Mine is holding up perfectly still after about 2 years. After seeing DBR's update after he took it apart after 2 years and it looked like new I wasn't in a hurry to take mine apart to clean. I will be doing it in the next few months but I anticipate it to look brand new.
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DBR_Reef
Active Member
Yeah, it looked brand new after 2 years. I’ve also done icp test and saw no metals, including titanium
mrpizzaface
Well-Known Member
What is the heat exhanger of choice these days? What size would I select to heat approx 450 gallons of water?
This?
https://tinyurl.com/rpbqz3x
im not seeing what pump people are using for the tank side to get water back from the ex-changer to the tank- somewhere i read about head loss through the ex-changer being high--i under stand the distance from tank makes a difference just trying to see how long of runs people have and what pump is corresponding with it
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DBR_Reef
Active Member
Depends on the valves-
the 2 ball valves are so you can isolate and remove the system without turning off house water.
the check valve is unnecessary and an extra failure point if you have the motorized ball valve- I had one and threw it in
The motorized ball valve is to prevent any thermal siphoning or reverse flow through the system when water is turned on elsewhere in the house- Depending on your setup, I would probably call this necessary, although if you use a check valve you might be able to do without.
I should have specified motorized ball-valve, but thank you for covering all of the bases. I found a video of a disassembled Taco 007-F5 pump which is what I ordered, and it is not a rotory vane pump, so the water can pass through the pump freely when not running, so I do believe they are necessary. I found them on the US Solid website for the same price and free shipping. My 55,000btu titanium heat exchanger is ordered, and I will be be using this system for cooling also since I am fortunate to have cold water coming in from the main. So the pump, 1 motorized valve for the hot, 2 for the cold, and a manual ball valve to gate down the pressure of the cold water to waste.
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Rst
Active Member
Hi,
Hoping someone here can help me with some advise. This discussion is very interesting since I have a 150gal RO reservoir that I need to keep warm in the winter months. This RO tank is located in my unheated garage. It so happens that I also have a unused gas fired instant hot water heater that was previously used years ago, to heat a 200 sq. ft concrete floor with 1/2" PEX lines embedded in the concrete floor. This room now no longer needs this heat. I would love to now utilize this instant hot water heater for purposes of heating my 150 gal RO tank instead.
Two questions: 1. There is approximately 30 feet distance from the location of the hot water heater and the 150gal tank. If I just run PEX all the way to the tank, much of the PEX lines would be exposed to the garage cold air and therefore be very inefficient. Is there a way to avoid the loss of heat before it reaches the tank?
2. I noticed the titanium heat exchange suggested in this thread at post #213 by DBR_Reef. Would using a titanium heat exchange like this or similiar be an advantage over just running long loops of PEX inside the RO tank?
Any suggestions?
Thanks, Ron
Hoping someone here can help me with some advise. This discussion is very interesting since I have a 150gal RO reservoir that I need to keep warm in the winter months. This RO tank is located in my unheated garage. It so happens that I also have a unused gas fired instant hot water heater that was previously used years ago, to heat a 200 sq. ft concrete floor with 1/2" PEX lines embedded in the concrete floor. This room now no longer needs this heat. I would love to now utilize this instant hot water heater for purposes of heating my 150 gal RO tank instead.
Two questions: 1. There is approximately 30 feet distance from the location of the hot water heater and the 150gal tank. If I just run PEX all the way to the tank, much of the PEX lines would be exposed to the garage cold air and therefore be very inefficient. Is there a way to avoid the loss of heat before it reaches the tank?
2. I noticed the titanium heat exchange suggested in this thread at post #213 by DBR_Reef. Would using a titanium heat exchange like this or similiar be an advantage over just running long loops of PEX inside the RO tank?
Any suggestions?
Thanks, Ron
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DBR_Reef
Active Member
1. If you do not feel like moving the hot water heater or the tank, Pex is actually a pretty good insulator, and you could put some foam pipe insulation around the pipes for further efficiency. I would also make a thermal blanket for the RO tank- I would recommend the foil covered bubble wrap, and either heat jointing it or using foil tape- this would give a nice clean install- there are better ways of doing it but this is cheap and easy.
2. The titanium heat exchanger has the benefit of taking up less space, definitely not leaching chemicals from the exterior of the pex into your ro, less prone to failure, and generally being easier to clean and tidier. However titanium is WAY overkill if you are only planning on using it for ro, and not to heat mixed saltwater. A cheaper stainless version would be perfect if it is only going to come in contact with RO
Just an extra point of advice, I would suggest making the temperature set points fairly far apart for the reservoir, as a consistent temperature is not that important, and this will keep the heater from constantly cycling on and off, which I imagine might be rough on a tankless.
Rst
Active Member
Great info. Thank you. I prefer to utilize a heat exchanger hoping that this would allow the most space left for maximum water volume. Your previous post provided a link to titanium heat exchangers that was not outrageous ($99) cost. Choosing titanium would also allow me the flexibility to change this tank later to salt water premixed. Would the specific previous linked exchanger you provided be an example of one to circulate the hot water through my pair of PEX lines? PS - I see 2 pairs of connections pictured, but I don’t understand the need for the 2nd set of connections. I am guessing that I need a different kind of exchanger. Wouldn’t an exchanger with just one in & one out all that would be needed? (act as a radiator). Sorry I am not understanding.
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DBR_Reef
Active Member
I'm not sure I completely understood your question, but I think it has to do with the type of heat exchanger- If you want to heat a tank of ro you really have two choices:
1. a shell and tube, which is the type I use in the initial post- a little more compact, and if you have to run a return anyway, possibly slightly nicer, but more expensive
2. a coil heat exchanger- that coil can be pex, stainless, titanium, copper (not for a reef obviously, but for beer is good!)... but it is just a coil of material that you run hot/cold water through and submerse in your tank.
I would probably suggest a coil of titanium, as it is one less pump you need to run, and just submerse it at the bottom of your tank.
Aquarium Titanium Evaporator
www.fish-street.com
The problem with that one is it has brass connections that would be submerged- obviously a problem. I would probably just cut those off and slide some vinyl tubing over the titanium tube, and tighten down with some 316 stainless hose clamps. This is a ok option, and definitely cheap, but perhaps not the best option, as it puts a possible leak point right in the ro tank. If you could find just a coil of titanium tubing and make those connections outside the tank that would be better. But probably not easy- since it is just a ro tank I would probably say go the cheap option.
Just an fyi- you are creating a closed loop - if you fill the entire thing with water it will pressurize when heated- the pex might be able to absorb some of that, but you will get a ~2.5 % increase in volume for every 100°F rise. If you do not build in someplace for that extra water to go you are building a very leaky heating system, as the pex of vinyl will burst first. But you do need a pressure tank, line of empty pex, etc.
I have mine built and running well. It raised temp 1 degree in an hour on my 700g system. I’m using my Ranco controller now but would like to find something to control cooling also, like the Inkbird but I notice that it is accurate within 2 degrees. I’d like accuracy closer to .1 degree and also have an app associated to it so I can monitor temp while I’m away - without having to get an Apex.
I still have to tidy up and hook up the cooling side wiring, gate valve and cold water waste line, and secure the pex.
I still have to tidy up and hook up the cooling side wiring, gate valve and cold water waste line, and secure the pex.
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