Cooling and heating using heat exchange coils

[krayziez]

Has anyone used heat exchange coils? Here's a video on what I'm trying to do:
https://youtu.be/5Awsk1y1GeE?t=1m39s

I don't know what the material is used and not sure where to get it. Hopefully someone could help. Can I just use normal tubing? And by the way, are any tubings toxic to use for salt water?

Also, Than, the guy on the video says he has to turn on the cold water manually. I was wondering if there's a way this could be done automatically by plugging in some type of device into an Apex controller and having it turn on when temp is out of range. I'm trying to find this, but they are all on timers and nothing plugged in electronically. It's a type of solenoid I'm trying to look for but triggered electronically instead.

Any help would be great. Thanks!

 

[billsreef]

The most effective heat transfer is going to be with metal tubing. Only metal tubing I would use in a SW application is titanium....which is not cheap. Plastic tubings should be SW safe, but will not be very effective at heat transfer.

As for temperature control, a simple solenoid valve hooked up to a relay controlled by something like an Apex will work for turning on and off the cold water.

 

[snorvich]

And, it will also depend on the temperature differential you are trying to manage; with plastic tubing, no matter what temperature the liquid is lowered or raised to, the heat transfer will mean that only small differentials can be managed to the conductivity of the plastic medium.

 

[salty joe]

I use 100' 1/2" PEX coiled in my filter. It's connected to 500' 1/2" PEX that's wrapped around my foundation. It's controlled by a Ranco hooked up to a pump. It can pull the temp down 1 degree F in 800 gallons in, IDK an hour or less. I need to figure out how to set up a monitor that tells me how often and for how long the pump runs. It's keeping the temp rock solid at 81-82F.
I use the same coil hooked to a tankless water heater in the winter. So if you have room, PEX works well. BTW, if you use PEX and plan to heat with it, use PEX al PEX.

 

[el aguila]

I didn't look at the video link, but there are plenty of people that do this.

I have 400g system with about 200' of plastic tubing coiled in a 100g Rubbermaid sump. My controller actuates a solenoid. I'm on a water well and my tank temp is right on the money all the time. Even when the AC was out for a week.

Excess water and RO waste goes out to a landscape pond that keeps it topped off during our NC summers.

I got the idea on here from Rand Farley Holmes. There is someone else on here that uses one with his hot water heater. I just question if that would be cost effective for my system.