Difference Between Type L & ACR Copper Coil??

[fst2011]

Hello everyone,
I was hoping someone can share advice, tips etc. I plan on getting 55gal steel drum & turning into wood burning pool heater. My question is about which type copper coil would work best, and still be safe to use.

I'm able to get 100ft of copper coil at discount price. Not much but every little bit counts. Anyhow Type ACR is much much cheaper then Type L. Is there a real big difference? Big enough to spend the extra cash and use Type L. Is ACR still safe to use with the pool?

Please any info would be greatly appreciated.


Thank
Lisa

[Mike90250]

While copper is a great heat conductor, I question how safe it is in a wood burner, it quite easily work hardens and would crack. I'd prefer you look at stainless steel as the coil in the firebox, and work out a intrinsically safe way to prevent a water vapor explosion if the pump stops or an air/steam bubble blocks water flow.

Additionally, copper and pool chemicals don't mix well, the chemicals will quickly (year or less) damage the copper.

[SWFLA]

ACR is fine. O.D of the tube dimension is true. Whereas L is plus 1/8in. The fittings are not interchangeable. It is not processed/manufactured with oil. I would use flares for the joints. Cheaper heat exchangers are made from cupro-nickel more expensive ones titanium. If you keep your free chlorine around 2 PPM you should be fine that's generally what utilities keep the levels at feeding you are house. Don't run it when you're shocking the pool. Copper does not like acidic pH is but neither do bathers. It will last a fair amount of time. And don't get crazy trying to heat it too fast it's not a steam machine.

[J.P.M.]

This sounds too dangerous for me to comment on so I won't except to say don't do it.

[LucMan]

ACR copper " airconditioning and refrigeration" cleaned and dehydrated .
ACR copper is the same as L copper except that it is cleaned internaly then capped on the ends to keep dirt and moisture out. It comes in 50' coils vs 60 ft for L and the sizing is marketed as the OD size only, outer diameter, for example 3/8" od is the same size as 1/4" id L tubing.
K tubing has a heavier wall and is used for under ground.
M tubing is thinner wall and used for hydronic heating or where lower pressures are used.
All copper tubing is nominally OD sized so all fittings will work, the wall thickness and the id does change for the different types. The fitting sizes are interchageable just have to convert from id sizing to OD, 3/4" L= 7/8 od acr, also in refrigeration long radius elbows are available for decreasing total equivalent pipe length by reducing overall friction.

[SWFLA]

This sounds too dangerous for me to comment on so I won't except to say don't do it.

The safe way to do it is fill the drum with water and build the fire underneath the drum.

[J.P.M.]

The safe way to do it is fill the drum with water and build the fire underneath the drum.

Safer maybe, in a way somewhat analogous to intrinsically safe as the term is usually applied to electrical equipment for hazardous locations, in that open heating of water will probably avoid boiling/overpressurization in the pool water line, but it seems dangerous to me from other perspectives as well - starting with what sounds like open flame problems and how to handle them. Aside from the danger that goes with what looks like a lot of ignorance about materials, design and what's required to heat water safely, if nothing else, the whole thing still sounds impractical.

[SWFLA]

I agree, I use a heat pump. Easy way to make sure you have no net credits. Biggest hog I own. 10.5 tons but there is no need to constantly heat the hot tub.

[fst2011]

I can't begin to express how much I appreciate the advice. As for dangerous...i don't think it is based on videos I've watched. The video shows different ways they ran the coil in the 55gal drum. It does amazing job getting it hot. Most only take a day or so to get hot, then I planned on making solar tubing box to maintain the Heat. So should only need to run few times. I'm home all day so running with not be that bad...yes there is labor involved but that's the trade off.

Yeah a reg heater would be nice and stress free but don't have the extra 2K. I just got done spending $1500 on ramp to get my son's handicapped chair into pool.

The vids of people using 55gal steel barrel with copper inside also seem to continue to work. Unless something bad
happened and they never posted a follow-up... I'm leaning towards it's ok.

However my main concern was the real difference between ACR & Type L.... would I be better with one over the other? Is the ACR dangerous for my setup? I'm just worried cause it's so much cheaper then the Type L, that maybe it's going cause a problem.

Someone mentioned about the ACR being cleaned inside... that sounds like a good thing, no? I don't have worry about oils or etc getting into pool, unless I'm looking at this wrong?

Any other info would be great. Thanks for taking time to read and share your advice.

[sensij]

However my main concern was the real difference between ACR & Type L.... would I be better with one over the other? Is the ACR dangerous for my setup? I'm just worried cause it's so much cheaper then the Type L, that maybe it's going cause a problem.

Are you sure you are looking at it right? As others have pointed out... 3/8" ACR would be equivalent dimensionally to 1/4" type L, since ACR is specified by OD and type L by ID. If you are finding that 3/8 ACR is cheaper than 3/8 type L... Well, yeah, it is smaller tubing.

[LucMan]

Acr is usually more expensive per ft, remember it comes in 50 ft roll and L comes in 60 ft plus the od and id differences.

[fst2011]

I'm very confused as to why you seem to think it's more money for ACR... however even if it was, this was not my concern. I truly do appreciate the time everyone has taken but I thought I explained I needed to know any real difference, like is Type L safer... is Type ACT better for heat?

I'm sorry if this comes off rude and apologize for this. I really do.

I can get a 100ft Type L 1/2 for $163.00
BUT 100ft Type Acr 1/2 for $119.00

So it is actually cheaper. I've noticed they say one is clean inside, does that matter for what I want to do? As far as one being thicker, does that "TRULY" matter for what i want to do with it?

https://m.grainger.com/mobile/product/MUELLER-INDUSTRIES-100-ft-Soft-Coil-Copper-Tubing-4WTC2?breadcrumbCatId=7726&fc=MWP2IDP2PCP

Site I'm looking at to get the pipe. Lastly if you guys really are seeing a high price for Type L then I don't understand cause I thought price for copper is same for everyone.

Thanks for any and all info and again if my reply comes off wrong I'm truly sorry just I'm getting frustrated with all this, I just want to try and heat the pool for my son and safe money if possible. I greatly do appreciate all of the help... I'm sorry.

[fst2011]

Bump... need advice please. It's very important.

[LucMan]

One more time! acr is 1/2" od or 3/8" id
type L is 1/2" id 5/8" od they are not the same size.

[sensij]

One more time! acr is 1/2" od or 3/8" id
type L is 1/2" id 5/8" od they are not the same size.

I was surprised, but the prices that he wrote above are actually what Grainger lists. Both are 1/2" OD, 3/8" ID, although the type L is 0.035 wall and the ACR is 0.032 wall, and therefore carries a slightly lower pressure rating.