Copper coil?

[NCFord]

Hey I am getting ready to order a copper coil to heat my open storage and was wondering if anyone
has a source. I need one that is capable of 100,000 btu's as my boiler i 100,000btu. I have priced
one or two and they are about $1000. It thought about making my own, but it may not save that much
since copper is so expensive.

 

[Blue Tornado]

Hey Ford:

Have no info for you but offer sympathy on the cost of copper.

 

[bmblank]

I've got a ton of copper also. Not looking forward to another hundred feet of coil to add onto my domestic this summer.
It'll be worth it though.

 

[NCFord]

I think I need close to 200' of 3/4 copper to cover my 100,000? Does this sound about right? I have a sqaure
tank that the inside dimentions are 5 feet by 8 feet and am thinking of using straight copper and buiding a my own square heat exchanger. It would then sit on the bottom of the tank. It would be a lot of soldering but could work. I have to price it with pipe and fittings. Since the whole thing would sit low in the tank I would think my exchange rate would be good since it would be in the lowest part of the tank. Don't know if it would be worth it when I could buy a roll of soft copper and make coil or just buy a coil.

 

[NCFord]

even Lowes has soft copper for $165 for 60 feet. It says it Type L. Does it matter what kind of copper I use?
I can get 240 feet for about $700. That's about $400-500 less than buying a coil from someone.

 

[dswitham]

I used 5/8" OD copper refrigerator tubing to make 4 -100 foot coils for my unpressurized storage. They are manifolded into a 1 1/4" pipe. It works great for my system. I don't know how many btu's it transfers though as I am not trying to transfer all of my boiler btu's to storage. They are resting on little blocks to keep them off the bottom of the tank and are nestled together to make only two coils in the tank. The domestic water coil hangs in the top of the tank and is another 100ft coil. I like hot showers and so only can go down to about 120 top of tank temp and get a nice shower. My son and husband don't mind showers down to 115 top of tank temp.

I got my tubing from here:
(broken link removed to https://coppertubingsales.com/storefront/product_info.php?cPath=223_119&products_id=760&osCsid=cm1cdu4qe0jfbtm085vd42sdi0)

 

[NCFord]

Thanks, I want to try to size the coil to the boiler as all I want to do is "charge" the tank at all times.
Dswitham, do you have any pics of the 5/8 copper and 1 1/4 manifold? I was just going to run a great big loop with 5/8 or 3/4 copper tube, but I like the idea of a bigger manifold since the line from the boiler will be 1 1/2 at the smallest.

 

[dswitham]

I can't seem to find any pictures of them, sorry. I will keep looking though. In my first homemade tank we left them all separate and they worked, but in the new tank we interlaced two coils together. It was not easy to do and would have been easier to do it as I shaped them. They go from the bottom of the tank to the top of the tank and are about 1 foot in diameter. The bottom end has a 90 and then goes straight up, 90's again and comes out of the tank at the top of the wall. The top end we gently curved it straight and put a 90 at the top and then straight out. After they come out of the tank they go through a section of pex and into a black iron manifold that we got from home depot. All of the pipes come out between the cover and top of the side of the tank. The cover of the tank I have is designed for the pipes to exit in this location. So in all, for the boiler coils I have 8 -1/2" pipes (the 1/2" copper fittings fit the tubing) coming out of the tank. (4 tops and 4 bottoms) We tried to keep all of the plumbing for the coils the same length. If we hadn't been in such a rush to connect them up (long story), I would have liked to connect the bottoms of each interlaced coil to each other in the tank and come out with say 1" and then manifolded the two pipes into the rest of the piping. Same for the top. But what we have works, so it stays.
I don't know how much tubing you would need for your boiler. Like I said, I don't send all of the btu's to the storage tank (which is in my basement). The rest of them go to a pool we have in our greenhouse, which in turn helps to heat the greenhouse.

 

[kopeck]

American Solartechnics makes them, just check out his site.

Tom is also a forum member so he might see this.

K

 

[NCFord]

I've talked to Tom, Nice guy. If I buy a coil I will get it from him.... still $1000 plus shipping.

 

[stee6043]

Is it too late to consider pressurized storage? Many folks around here can score two used propane tanks for less than you're looking to pay for a single coil...

 

[NCFord]

I agree that 1000 gallons pressurized would be better but....by the time I find(not easy) and buy(about $200-500 apiece) plus the cost to have someone weld everything plus the fact that I don't have quite enough space for 2 tanks leaves me with open storage. I might also add solar at some point and that is much easier to do with open storage

 

[ozzie88]

ever try a coil from a hot water --steam jenny? they sell them by them selfs and i have used them in a DHW tank i made whil back,heavy-duty and different sizes,

 

[BoilerMan]

but I like the idea of a bigger manifold since the line from the boiler will be 1 1/2 at the smallest.

Why 1.5"? at 20 degree deltaT you can move 100,000 btus through a 1" copper pipe. 1.25" Would certainly be plenty. 1" PEX on the other hand is not that same ID as copper.

TS