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Very Old Rheem System

696 Views 9 Replies 5 Participants Last post by  yuri
OK how do I search for a very old system? I have the model number and the serial number, but when I go to the mfr website I get no results. I do believe the date of mfr was July 1978 based on s/n, but can't seem to find anything else out about it, especially the SEER rating, (Which is the challenge I was given)....Any old timers can help out this 62 y/o newbie?
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Is SEER the only information your looking for on that old girl?
A 1978 unit may not have a seer rating.

It may have an EER rating which is derived from testing at 95F outdoor/80F indoor.

Probably in the 6 to 7.5 range unless it was something fancy.

Just remember- don't assume what you have now is the correct size.
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A 1978 unit may not have a seer rating.

It may have an EER rating which is derived from testing at 95F outdoor/80F indoor.

Probably in the 6 to 7.5 range unless it was something fancy.

Just remember- don't assume what you have now is the correct size.
Most likely correct.
SEER ratings were not really instituted until around 1978.
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That was the challenge, though I believe it's for me to research and find out that SEER ratings did not exist in 1978?
They would have just been instituted around then. Even if it had one back then, it wouldn’t have been widely publicized.
Why are you inquiring? Are you replacing this unit?
Why are you inquiring? Are you replacing this unit?
My thoughts, too. Just morbid curiosity or something else?
Rheem serial #s are not easy to read and it may not be 1978.

If you can find a sticker on the contactor or get the serial # off the top of the compressor and it has a 78 in it then it may be true.

Pretty rare those may still be running. I put a Canadian built Keeprite in Mom's house in 1980 and it wore out and 99% of them are worn out and going away.

Back then it would have been between 7-8 but we only had one style of unit to choose from so no one cared. I have found info on some very old Lennox units and none were over 8 at that time.

However those old machines a lot of them had Tecumseh compressors which were built like tanks and old school Maytag washers so a few are still running.
I still see some old units in my area - it's probably refrigerant leaks that take them out more so than compressor failure.
Older units die/get replaced because the valves wear out and the compression ratio is gone. Then your Delta T is 10-13 and it cannot keep up with the demand.

We are talking about recip compressors as scrolls are mostly under 20 yrs old.

Plus a connecting rod breaks and they seize up or the windings short.
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