copper fresh water tank and lines for cooling/heating coach?

happycamperbrat · November 04, 2011, 11:41:49 AM

I have stainless steel roof inside my coach. Im kinda thinking about making a copper fresh water holding tank as that I dont want aluminum or plastic because of contaminates.

In my wild thinking, I came up with additional cooling and holding capacity by running copper tubing inside on my ceiling, attached to the stainless steel. The tubing would be attached to the copper fresh water tank and I could even bore holes into the refridgerator so that the tubing runs through it for additional cooling (which in winter time could be capped off when I switch to heating instead of cooling the coach).

For winter use, I could also run copper tubing along the bay floors (my floor is thick plywood and my bulk heads are mild steel). I would probably need something to keep bimetal corrosion down where the tubing would touch the bulkheads but I dont think I would need it up top on the ceiling because stainless steel is supposedly often recomended for fastners on copper. This tubing would also run through the engine area and through the heat source for the coach.

I would have a small 12volt pump to run water through the pipes. Around here 3/4" k copper is not to be found, that has to be ordered online. The largest diameter k tubing I can find is 5/8" but I can find L copper in 3/4"......

belfert · November 04, 2011, 12:18:45 PM

You're just making your fridge work all that much harder during warm weather by using it as a cooling source. If your fridge exhausts the heat to the interior you are just transferring heat back to the interior.

TomC · November 04, 2011, 12:45:31 PM

A refrigerator typically has a very low BTU/hour rating as compared to air conditioning. Typical BTU for a refrigerator maybe around 3,000btu's as compared to have say three 13,500btu/hr air conditioners for a total of 40,500btu/hr. As you can see the refrigerator would add about as much as someone blowing on you. Best to leave the refrigerator alone. Copper will be shedding contaminates also. Never heard of a water tank made of copper.

belfert · November 04, 2011, 12:52:33 PM

Copper is used for water lines so why couldn't it be used for a water tank? Maybe there is a good reason why not to use it for a water tank. The main issue I could see with a copper tank is the cost with copper so high.

Seayfam · November 04, 2011, 01:31:23 PM

Why not use stainless steel? I would think that using SS would cost less and put off less contaminants, also would hold up better for the long run. Mine is built out of SS and is built in under the bed. Saves on bay space if that is an issue.

Tikvah · November 04, 2011, 01:54:51 PM

Hot water running through copper or pex in the ceiling along with the Stainless Steel panels will work wonderfully for heat. However, cold water during the warmer months will make condensation. The condensation will destroy your bus.

Heat = YES
Cool = NO, NO, NO

Dave

Utahclaimjumper · November 04, 2011, 01:57:23 PM

There is a good reason all RV manufacturers use poli-urethane tanks,, no contaminents and water can be left in for long periods.>>>Dan

bevans6 · November 04, 2011, 01:58:40 PM

I think the main reason copper is not used is cost of the material and fabrication costs. Tig welding copper is doable, but I think it's a fairly expensive process, I think the melting point of copper is pretty high and you use special gasses to get the temp. I wouldn't think that you would want to solder up a copper tank, but you could with modern lead free solder I suppose. It's heavy, it is quite susceptible to fatigue cracking and some types of water with higher acidity can leach copper out and cause copper poisoning. You need to pick the grade and alloy for food-safe uses. Stainless is used in tanks for food-grade systems, it's easily weldable and easy to fabricate. I personally don't have an issue with food grade plastic for tankage. I have a separate drinking water supply that uses those big jugs you can buy, I don't use the tanked water. I don't trust water supplies all that much. Municipal supplies are fine but taste funny, and too many scares with ground water and well water so if I haven't had it tested, I don't like to just blindly trust it.

Brian

prevosman · November 04, 2011, 02:14:36 PM

The concept of a copper tank is appealing, but the ease of working with and welding stainless compared to copper is a world of difference. Also, copper is pretty reactive. so it is going to change in color and appearance quickly compared to SS which will look exactly the same decades from now.

Jeremy · November 04, 2011, 05:39:09 PM

My calorifier tank is made of copper, and the manufacturers claim it to be an 'anti-bacterially' superior material for drinking water tanks than stainless steel or plastic.

This link is to a PDF in which they talk about this:

http://www.surejust.co.uk/PDF/brocher1.pdf

(Shame they don't know how to spell 'brochure' though)

Jeremy

CountingFireflies · November 04, 2011, 06:19:03 PM

I think the copper tank would be great for fresh water, but if you can afford it, I would pick stainless for one reason only. It doesn't corrode. We have huge hesitations drinking water out of our plastic tank, and we definitely don't use the hot water that has run through the plastic tubing through the aquahot for drinking. Metal is better hands down.

For the heating/ cooling, I think you'd have to do the BTU math and figure out if it's worth it or not. I don't think you can carry enough water to make it work out right.

Solar water heating should be an easy one to accomplish, and is next on my list of 'fun bus projects.' Just like you said, a small pump circulating to the rooftop.

Chris.

happycamperbrat · November 04, 2011, 07:38:52 PM

Okay thanks guys! That was why I posted this idea, I knew you guys would know

In my area we have alkaline water so copper is supposed to be the best for us. Stainless however was not something I considered, just because I didnt think of it. Ive seen fittings soldered onto copper pipes used for water and it looked pretty easy material to work with.......... no? I did not do any math regarding btu's so apparently that wont work. As for the condensation........ if the insulation is in between the roof and the pipe then I didnt think condensation would be much of an issue. Also the pipes would/could be drained in their off season, for instance the ceiling pipe could be drained when only the lower heating tubes are needed and visa-versa........ yes? no?

Nick Badame Refrig/ACC · November 04, 2011, 08:01:02 PM

Hi HBC,

I use polly tanks but, I filter all my water with commercial grade submicronic filtration system by evrepure.

This may ease some of your difficulties with the copper issue and spend far less in tank materials..

http://www.everpure.com/SiteCollectionDocuments/Foodservice_Product_Portfolio.pdf

I have the duel i2000 cartrage system [QC71 7CLM Twin pg 14] which I replace every spring.

Nick-

rv_safetyman · November 05, 2011, 07:42:13 AM

Dan, I think most "plastic" tanks are made with polyethylene not polyurethane.

We use the polyethylene tanks (the vast majority of commercial motorhomes use them as well) and do not worry about the health issue. First, we use a form of chlorine (swimming pool treatment - much cheaper) and then, like Nick, we use a two stage filter for drinking water only.

As has been said, copper is very expensive and not a good structural material.

Jim

happycamperbrat · November 05, 2011, 09:30:21 AM

The copper would probably be okay as long as I only travel around in my backyard

The stainless steel sounds way better for us. I just found this tank on the e store and it doesnt seem bad. What do you guys think?

http://www.ebay.com/itm/Stainless-Steel-Wine-Water-Storage-Tank132-Gal-/200604434476?pt=LH_DefaultDomain_0&hash=item2eb4f4c02c