Aluminium & Copper tubing.

[4sac]

I've just seen this on a suppliers site which i haven't come across:
http://www.ryanairconspares.com/racs-lawton-dual-conditioning-tube-p-2454.html?osCsid=4kqoc08m9svd4ld6sfq7fdk3r3

Has any one used aluminium pipe before? If so what are the differences when working with it? It's significantly cheaper but is it as good as using copper or considered inferior. Apologies if this isn't new technology I just haven't come across it before.

[John_Galt]

Very little experience with refrigeration in general here, and I've never used aluminum for refrigerant lines. However, I have used aluminum in the past. Pure aluminum is an absolute bear to solder or braze. Generally much more trouble than copper. Heat transfer is about half as good as copper for pure aluminum, but aluminum oxide has thermal conductivity well under one tenth that of copper, and there's always a thin layer of aluminum oxide on any aluminum you would use. That means it will always underperform your calculations for pure aluminum, usually by a significant amount.

That link went to a page for some kind of aluminum shell/copper core bonded tubing. They claim "no scrap value" and therefore safer to leave it in less secure locations. That's not 100% true. Aluminum is worth around a quarter the price of copper as scrap, and depending on what the weight ratio is, that stuff should scrap for over half the value of an equivalent weight of copper.

I wouldn't use that stuff in any kind of heat exchanger. For locations where you need "insualted lines," it could be interesting. It looks like they recommend soldering the copper core onlly, or stripping back the outer shell, expanding the copper core tube and inserting another piece of copper to solder everything together for a joint between two clad pieces. That would work, but seems like a lot of trouble, compared to pure copper tubing.

I don't know pricing in those currencies, so I'm not sure if there is a price advantage.

[zenen]

We only use this pipe in closed indoor - outdoor installations with no need of welding. We would advice copper only for all installations

[4sac]

Thanks for your feedback guys having spoke to someone who's used it that seems to be the general consensus so i'll stick with the copper for now until i hear otherwise.

[akachillywilly]

They have a new product out her in LV its called "Super HVAC PRO" it's basically a "glue" for copper, alum, and brass. I've tested it it will hold up to 800psi after 12 min. No torch or heat needed. I know it sounds crazy but I tested it. Haven't had the guts to use it on a customers equip yet but soon. And if the thieves are as bad there as they are here...any kind of metal is subject to be stolen. Also the product claims it's ideal for reversing valves!

[Makeit go Right]

If I recall, these two metals have different co-efficients of expansion, so will expand/contract to differing lengths when heated/cooled. And that constant stress going on during the life of a system, repeatedly expanding and contracting, must take it's toll before too long.


And if used on an air heat-exchanger, doesn't the ali tarnish in a different way to copper and reduce heat transfer?


Guess it's a bit early to answer these questions.

[Boxer]

Why would you have copper and aluminium within the same tube ???
Copper is tried and tested.
Aluminium is the future !!

[maire]

The aluminium tubes are cheaper and can resist corrosion. These are used as general purpose.It is easier to weld. It is also used in nuclear application due to its strong feature.

[soleowner]

I don't think HEX coils are the issue. Aluminum (AL) piping does have lower thermal conductance, which is good. VRF and conventional low, medium and high temperature refrigeration systems waste Btu's between the ODU and IDU.

I tend to think manufacturer's from the past and present have set the tone for use of copper (CU) piping. I'm not sure why. I do know that most decisions are based on economics. And the economics of training contractors to properly install AL to CU is not in their best interest.

I have heard that Daikin is bundling Reflok couplings and Aluminum piping with their VRF systems.

Does anyone have documentation on Daikin approving the use of Aluminum piping?

We need to lower the cost of VRF system installation. AL might be one of the answers.

[charlie patt]

well i done it i installed 36 mhi units in newquay and one of them on pure alloy pipework 12m piperum 13mm insulation it braised ok it flared ok why? the one unit i put it on is comeing out in december and i want to sea what the pipework is like sat in flex for 8 months will keep you in the loop

[install monkey]

reply in less than 6mth otherwise the thread will be locked unless you ask webram to keep it open

[frank]

reply in less than 6mth otherwise the thread will be locked unless you ask webram to keep it open
any of the mods can reopen a thread if you feel it warrants further discussion

[TonyECO]

Charlie,
That's interesting - would be interested to learn further how it worked for you? - On other factor which we have been investigating is the application of a very well known product to offer even further protection to aluminium pipe in harsh locations - but lets see

[TonyECO]

Some info for all to share - manufacturers are now starting to validate our product

[assailant]

ive seen a sample brought back from the ARBS expo in Melbourne last month.

the aluminium flares really nicely and brazes very easily.

the real beauty is in its ability to be formed and reformed over and over again.
we bent one short sample 3/8" piece about 50 times, making bends and then straightening again!

copper obviously work hardens almost straight away.