Remembering Early All-Aluminum Coils

I read Joanna R. Turpin’s article, “Aluminum vs. Copper: The Great Condensing Coil Debate,” [Feb. 18] and I would have to disagree with parts of it.

She stated under the subhead “Aluminum Gets A Foot In The Door” that aluminum tube/aluminum fin condensing coils first came about in the 1970s. General Electric was in the hvac business at the time, and had built an air conditioning system that used an all-aluminum condensing coil. She quoted someone who said that GE was the only company that did that. I believe that you will find that Chrysler Airtemp Corporation was testing an all-aluminum coil at the University of Miami in the late 50s and early 60s. They were testing it for salt corrosion and cost effectiveness.

Chrysler produced thousands of condensing units with all-aluminum coil. I know this because I installed hundreds of these units in the Tampa Bay area. We were one of the largest Airtemp dealers in the South. The problem with the all-aluminum coils that Airtemp produced was brought on by the 180-degree return bends on the condenser coils. The factory had a problem of stretching the aluminum bends too tight, and they would have a tendency to crack. However, the main production problem was from the compressor discharge copper where it joined to the aluminum coil. Airtemp tried different welding procedures and coupling kits but never was able to solve the leaking problem totally. Also, if air got to them, the joints had a tendency to corrode and leak. They were wrapping the joints with a plastic sleeve, but in time the heat from the discharge gas would deteriorate the plastic.

Other manufacturers tried the aluminum coils, but they also had design problems. GE has been a leader in using all-aluminum condensing coil with very few joints, and they have produced a bonding agent to secure their aluminum spike fins to the aluminum tubing for heat transfer. I have replaced just a handful of their condenser coils in the last 20 years.

I write very few responses to articles, but being in the hvac business for 48 years, I thought that this reply might be interesting.

Jack Joyner, President, Jack Joyner Htg. & A/C Co., Clearwater, FL

Coming Full Circle

I read Peter Powell’s article “Cubers and Flakers Have A New Friend” [March 4].

I worked on an ice machine back in the early 70s that had a revolving drum evaporator. I believe it was built by York. The drum was driven by a chain, similar to a bicycle chain. It was a good machine except that the shaft seals kept going bad and leaking. What’s old is new again.

Art Dobson, Educational Coordinator, Encompass Mechanical Services, Seattle, WA

Publication date: 04/01/2002