Historical Changes in HVACR
Barb Checket-Hanks
What were the biggest technological or market changes, in your opinion?
REFRIGERANTS
For many of us, the biggest changes came from the phaseout of CFC and HCFC refrigerants, particularly R-12 and -22. R-22, the mainstay in residential and commercial air conditioning, was in commercial production since the mid 1930s, though its initial uses were for industrial refrigeration, along with R-502.In the ’60s, the popularity of residential air conditioning really took off - and so did the use of R-22, which used to look like a nearly ideal refrigerant.
Open the curtain to the 1980s, when global warming, ozone layer destruction, and greenhouse gases took center stage. CFCs were the first to be phased out; their production was halted in the United States in 1995; R-22 will be phased out entirely by 2020.
R-22 has been pretty much replaced in new systems by R-410A. This refrigerant has higher operating pressures, and the new refrigerant uses a different oil, which is hygroscopic - it attracts moisture which, especially when it becomes entrained in the refrigerant, negatively affects system operation. And in order to make sure these new systems met federal efficiency standards - the second part of the one-two punch - the systems had larger coils.
For these and other reasons, we tend to look at the 90s as the decade of biggest change to the HVACR industry in our memory. Among the contractors who agree, one says it made compressor changeouts harder for techs, and they took more time.
COMPRESSORS
With the changes in coil size, and the complications this led to for many residential contractors, there were more compressor replacements than system changeouts while the industry developed smaller options.In general, though, there were macro changes in the compressor market. One reader observed that in residential through mid-commercial unitary systems, as well as in chillers, compression technology changed, “from 100 percent reciprocating in the 1970s and ’80s, to majority scroll.”
Others took a still longer look back, hailing the advent of hermetic and semi-hermetic compressors as bringing key changes to the industry. The older, huge reciprocating compressors, one reader said, were cast iron, driven by a large motor, and used sheaves and belts.
Hermetic compressors, he said, “took reliability to a much higher level,” and reduced maintenance costs. The new units were so much smaller, lighter, and less expensive, he said, that as a result of their increased use, air conditioning became more practical for homes.
OFFICES AND TOOLS
Lest we forget, computer technology changed the way practically everyone does business - in the typical office, it banished adding machines, hand written ledgers, Rolodexes, and peg board systems to a virtual museum of the obsolete.In the field, techs who once called in from pay phones, then checked in on very large cell phones, then smaller ones, can now check in online via their smart phones, and download information gathered from meters and other high-tech tools.
In the meantime, we remember asking this question of a residential HVAC installer about 10 years ago: What is the biggest change he had seen in tools? His answer: The Sawzall. Nuff said.
Now I want to hear from you: What in your opinion created the biggest changes to your business? And how old are you, anyhow?
Please send all replies to barbarachecket-hanks@achrnews.com.
Publication date: 05/09/2011