On Thursday, October 8, 2015 at 2:44:06 PM UTC-4, mj wrote:
replying to Ed Pawlowski , mj wrote:
esp wrote:

On Sat, 31 Mar 2012 11:06:48 -0400, "Stormin Mormon"
It has been on the market for years. It is cheaper to build, more
difficult to field repair.
All aluminum coils were starting to come into play in the late 1960's.
I worked for a company that made HVAC units until 1970 and we made our
own copper tubed coils and they started to buy aluminum coils.


I have a 3 year old Trane 4 ton unit. It has aluminum coil. It has been
serviced 9 times for slime on the coils. I have been told that if it had
some copper, like my two 1 1/2 ton units, I would not have this problem.
My repair company is trying something new-laying pieces of copper tubing
in the pan to try to stop the slime build up.

--

So here is an interesting take.

Whatever type of coil you have, water is the enemy.

Of course water will form from condensation when it is cooling.

So my take is that to reduce corrosion of the coil, set the blower to run all the time when you are using the AC.

This way when the compressor cycles off, the blower will continue to run and air dry the coil. You don't want the coil to sit there wet for no reason.

Mark