Microchannel condenser, my experience, I ask you your opinion

[gianpierone]

Good evening, everybody.
I always follow this forum with great interest because it's full of competent people, congratulations.
That is my first post and I am writing to ask you your opinion.
I am a thermodynamic engineer in an Italian company that produces refrigerated cabinet for supermarket
Recently I tested a multideck cabinet with built-in unit condensing, the condenser is a microchannel type.
It 'a very widespread application in the field of large distribution but I don't understand because.
From the tests I did I found many advantages and no disadvantage

The charge gas and 'reduced by 30%.
The temperature of condensation is less than the previous condeser
The pressure is equalized in less time.
The size of the condenser are small, only 2 cm thick.
Better ventilation in the unit condensig compartment.
Lower cost of manufacture.

So many benefits, but this application is not common used , why do you think?.

I apologize in advance for my little English language.

[NoNickName]

Ciao, gianpierone. As in most new products, it takes time from availability to acceptance. As a manufacturer of big chillers, we are using microchannel condensers in sizes up to 6 meters in length and found them to be cheap, reliable and all in all a better alternative to standard Cu/Al condensers.
The main advantage is that these condensers will no longer rely on copper that is becoming an increasingly expensive commodity.
We are now testing microchannel water coils (for free cooling).

[michaelm]

B”H
Gianpierone,
Who is the manufacture of microchannel coils.

[monkey spanners]

Are these micro channel coils made just out of aluminium?

How are they joined to copper pipe work?

Jon :)

[NoNickName]

Yes, they are completely made in aluminum. The joint is made with a bolted flange in a gasketed seating

This is how they look like

http://www.docs.hvacpartners.com/idc/groups/public/documents/image/img_pr_microchannel.jpg

[gianpierone]

Hi Michaelm, I have bought condenser microchannel to Val.Mex. in Italy, visit www.valmex.it

[gianpierone]

Hi Monkey , it is possible connecting the microchannel conder with blocks, lokring, nipless, copper pipe (by welding aluminium and copper).
I have used blocks.

[monkey spanners]

They look similar in design to vehicle air con condensers, if they are as reliable as the ordinary ones then its seems like a good thing.

[mikeref]

Very similar Jon. Excellent heat transferre. The only disadvantage when used in vehicles is when metal from a damaged compressor manages to get caught in tubes, however i think some vehicles have removable strainers now.

[Magoo]

Hi No Nick Name,
are these evaps flooded design.
magoo

[michaelm]

Hi Michaelm, I have bought condenser microchannel to Val.Mex. in Italy, visit www.valmex.it

B"H

Thank you so much.

[NoNickName]

Hi No Nick Name,
are these evaps flooded design.
magoo

No, they are not flooded, and they are not evaporating coils.

[Gibbo]

Carrier and York use microchannel coils on their chillers and are made by a US Company called Delphi

[billdozza]

these delphi coils tend to leak, already replaced about a dozen coils and would like to get a class action suit started

[billdozza]

i mayb a rookie poster but if it quacks like duck, walks like a duck most likely it is a duck, n coil is problem

[mikeref]

i mayb a rookie poster but if it quacks like duck, walks like a duck most likely it is a duck, n coil is problem
What is causing the condensers to fail? Corrosion or quality problems? Vehicle condensers of this type design take a beating from vibration and the elements for years..Mike.

[Gibbo]

Hi Billdozza

Which chillers do you have the coil leaks on.

[desA]

Automotive-style condensers suffer from a number of major failure modes.

The most common are:
1. Galvanic corrosion;
2. Fatigue/vibration failure.

[desA]

Galvanic corrosion mechanism:
The fins are generally clad with aluminium/silicon eutectic material;
The tube is extruded/formed, with no cladding;

After brazing, the tube generally tends to become sacrificial relative to the fin material, with consequent failure mode as tube corrosion.

The fin material can be adapted to move the galvanics around a little & extend corrosion life. This is a juggling act, specific to automotive operation & testing regime.

[desA]

Development of the next generation of copper-copper condensers is in progress.

[lawrence1]

Has anyone got information/facts on these failures?

[Bluestar]

how about danfoss sanhua mchx? any 1 using it?

[Bluestar]

in india danfoss started selling its mchx , any good alternative of danfoss?

[lawrence1]

billdozza,
Can you tell us more about the failures of the microchannel condensers please.
Lawrie