EER vs SEER in Hot Climates
Years ago, an HVAC pro convinced me to get a 14 SEER variant of a unit rather than its 16 SEER variant since both were 10 EER. According to him, SEER was based off a temperature of 83 degrees whereas EER averages around 95 degrees. Since few people here in the Phoenix metro area would even turn on their A/C when it is 83 degrees out and 95 degrees is pretty close to the actual average daily temperature in the summer, he concluded that SEER was meaningless here. Given that both units were 10 EER, it made no sense to “upgrade” to the more expensive model if both had identical performance in the end.
The thing is, I haven’t heard a single HVAC tech talk about SEER vs EER since then. You never see EER advertised, even locally. It’s hard to even find the EER rating of most units!
Yet my reading of the subject suggests that he might have been one to something. He was bang-on on how the two ratings are calculated. He was also right that EER doesn’t change anywhere near as dramatically as SEER does between model lines.
In fact, looking at the Carrier mini-split with a 42 SEER rating and compare it to a Mitsubishi unit with a 24 SEER rating and I see that both are rated at 15 EER.
Can I then read that as saying that in hot climates, the above Carrier and Mitsubishi units perform IDENTICALLY, even though they are advertised to be dramatically different? If so, should I be completely ignoring SEER and exclusively comparing units on EER?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part