The vast majority still use copper tube with aluminum fins.
For some years now, however, automotive A/C units have used an aluminum coil designed by Delphi called “Micro-Channel” which is actually better than the traditional copper tube/aluminum fin arrangement.
Here is Delphi’s product now designed for residential HVAC products. (Click pic to enlarge) Heres a better look in PDF format.
The only manufacturer that is currently using it is (afaik) York, which sells some of their condensing units with Micro Channel. (which I presume they are licensing from Delphi)
It is a dense coil that is less prone to damage, easier to clean and provides great heat transfer. They are not being used for evaporators (by York anyway…) because it is difficult to get water/condensate to flow off the coil.
So…the only place I see an all aluminum condenser is York (also sold under the names Luxaire, Coleman and Fraser Johnson) although it is possible that others are using also. I just haven’t see any, except York.
The above link suggests that there is an all aluminum evaporator (thats the indoor coil) although I haven’t seen any, anywhere, and when I spoke to the York engineers they told me that they couldn’t use Micro Channel for evaporators for drainage reasons.
I understand that Delphi’s Micro Channel has been in use for years now and is tried/ tested and proven.
I’m surprised it isn’t in wide spread residential use. I think its a good design, and good product.
I think the performance is actually better than copper/aluminum, at least as far as Micro Channel is concerned.
I don’t know, but I think yes.
I see no new products being rolled out with aluminum or Micro Channel. It wouldn’t surprise me if the whole industry went with a Micro Channel like coil at some point in the future.
Its anybody’s guess as to whether, or when, that might happen.