A/C "SEER" ratings.

Are "SEER" ratings a real way to judge different A/C units or are the faked numbers?

What are other inportant things to look for in a high end A/C unit?

I see Carrier is advertising 21 SEER units.

http://www.residential.carrier.com/products/acheatpumps/ac/infinity.shtml

 

They tell you how efficient the unit is. What kind and size of unit you need will vary, but the higher the SEER rating the more efficient the unit is. 21 is absurdly high (very good). We're building an energy star home and our units are 14.5 SEER I believe. Anything 14 or above is considered high efficiency. 18 is really high.

 

We just (as in last Thur and Fri) installed 2 SEER 14 units (upstairs and downstairs). SEER 13 is about the minimum sold anymore. Trane and Lennox offer SEER 21 or so.

The HVAC company gave me three systems, SEER 13, SEER 14, SEER 19. SEER 14 was about 40% premium over 13, SEER 19 was about 80% premium over 13. This is on the AC side (Evaporator coils, condensing coils, fan, filters, refrigerant, ancillaries).

That said, note that SEER is best for comparing units that cool in reasonably low humidity (much of the US). SEER gets less useful for comparing units in high humidity environments (like Houston), where the system has to take out high moisture loads.

Lots of homes in Houston are built with flex duct...bad choice, Ever seen a 24 inch return flex duct crimped down to 8 inches because the builder ran it between two "X" frames in the attic? Come to Houston. Does wonders for backpressure on the fan. We installed rigid ducting years ago and have NEVER regretted it. The house varies less than 0.5 degree throughout.

http://www.detailedinspection.net/defects/20070309%20036.jpg

 

I appreciate you hands on expertice... but tell me, in SC is it worth getting SEER 21 vs SEER 14?

Thanks!

 

I'm talking some HVAC classes. I just finished my first 4. I bought a house and all 3 units needed work. I felt was getting ripped off by the AC tech that came to inspect the units before I closed on the house. Long story short. he was charging me $2500 to get the units going and giving me no warranty for his work. I felt he was full of BS. So I got someone else to fix the units. All they did was put R22 refrigerant in one and hook up a loose wire on the compressor in another. Now my units work for $150

Anyway that was a rant. I decided to take HVAC classes because I have spare time.

in class we discussed all the SEER rating. Basically when you get into the super high Seer ratings. It's an over kill. All the Seer really means is that your AC will not work as hard on not so hot times (resulting in less electrical use). Instead of working full blast the whole time it is on. So in a Hot area you AC will pretty much work at full capacity almost all the time no matter what the SEER rating is. So it makes seer somewhat less significant on hot days. That being said. From 10 to 13 is a big jump. From 14 to 18 is not going to matter as much the higher up you get. Also the warmer or hotter and more humidity your climate has, the less and less the higher SEER rating matters.

It's kind of like a 35 year old man dating a 25 yr old woman. 10 years doesn't really matter. But a 21 yr old dating a 14 year old, in this case ( besides 14 gets you 10-20 ask R Kelly (-_-) ,7 years is more significant then the 10 years in the other scenario.

Also the name brand units Trane, Carrier, and Lennox are not really worth the extra money no matter how good the salesmen says they are. They have alot of extra useless bells and whistles that will give you tons of problems down the road. Those bells and whistles are almost always proprietary or made in very small numbers for limited times. So the spare parts will not be available in a few years after install when they start to give you problems. The best bang for the buck IMHO is Goodman. The quality and how long they will last is just as good if not better for 1/4 to 1/3 of the price of the highly advertised name brand units.

Stick with a 13 or 14 SEER rating, the prices are very good. The really high premium on the higher SEER is not worth. It's better to spend the extra money on better insulating your house, A/C ducts, and spray on radiant barrier in the inside of the roof in your Attic. That will save you more on your electric bill.

 

Thank you for that thoughtful post!!

 

Not in my opinion.

The delta between 14 and 21 was 6-7 thousand dollars total for 4 ton and 2 ton units. Just to pick a number that sorta makes sense, if you saved $100 per month for 6 months per year, it would take 8+ years to recover the upfront cost. That doesn't even take into account that you could invest the extra money, so the payback is more like 10+ years.

I lived in western SC for 6 years. While it's warm and sticky in the summer, it ain't Houston. I can't imagine spending the kind of money there that we spend here on summer electricity. So 20-30% savings for a SEER 21 is lower $ / month.

 

Depends where you live...

Our builder put in extremely efficient heating systems... but basic AC (moderate efficiency). I was kind of pissed, but now get it.

My heater runs for 6 months...

My AC runs about 20 days during the summer.

Who cares what the efficiency on the AC is? It would make little difference in the overall bill...


Now, if you live in Florida, you may want just the opposite...