Comparing SEER numbers or is it impossible?

[janderson901]

All things being equal or rather the lack of, in comparing SEER ratings for 5 ton AC units from Trane XL19i and Carrier Infinity 18. Which one has the better rating? Some of what I can find out is marketing mombo jumbo and it looks like the SEER numbrs go down with an increase in tonage. Carrier just stated a range of 15-18? Or shoud I forget about it because they are so close to each other?

Any body have an opinion as far as reliability goes for these two units. The 19i has a dual compressor and the carrier has a single two speed compressor.

Thanks for the help, I need it!

[jpb2]

imho. It is more important to find a good installer/dealer.

[fat eddy]

SEER ratings should mean the same thing for all brands, if one is higher it is suppose to be more efficeint. I don't know how true this is in reality but what you can bet on is that the higher the SEER rating the more it will cost you to buy it. If you use the A\C a lot it will pay to get a higher SEER rated unit if your use is 30 days or less a year it will probably rust out before you get a payback.

[BaldLoonie]

You need to look at exact outdoor unit/indoor unit match to compare. The XL19i is 19 SEER in 1 or 2 matches, the rest can be much lower, same with the Carrier. The 5 ton gets 15.5 to 16.5 SEER. The 16i gets 14-15 SEER with new technology instead of the old compressors.

As was pointed out, these super SEER units with their SUPER pricetags rarely pay off, you are spending the big bucks on the 2 stage. Don't expect any kind of savings over the life of the unit in many areas. Steamy Florida or Texas may be an exception.

The Trane is R22 dual recip, the Carrier is R410a with reversing recip both giving 50/100% staging. I prefer scrolls so if I were spending the big bucks, I'd go one of the brands using the modulating scroll. Only drawback is low is 67% not 50%.

[dash]

The Infinity is the superior control system,uses the latest GE variable speed motor,and provides the best in indoor comfort.That said, both are very good systems,and a major improvement to your indoor comfort.

[aircooled53]

The Trane 16.0 S.E.E.R. Best in the consumer rating department..
Carrier has good thermostat with there system..

But Trane has better air handler and condenser.

[Irascible]

I'd reconsider the true worth of uber-high-seer equipment. I've heard more than once anecdotally that some customers have had the pleasure of being unwitting R&D guinea pigs for the OEMs to figure out how to make this high seer stuff work right. Granted, that probably won't happen to you. But that money can be better spent.

Go for something more reasonable in the 12 to 15 range and spend the money you save making sure you get a good install. Get your ducts tested for leakage. A typical system leaks as much as a third or more of its air before the air makes it to the diffuser. Get that down to 5% and that 14 SEER with tight ducts will easily outperform the 19 SEER with typical ducts. Also get a contractor that will air balance the system to within 10% of the Manual J calculation. Again the increased performance in having a balanced system will pay much higher dividends than having that big SEER number. EVEN BETTER: Make sure every single room that EVER has a closed door has a dedicated return or jumper duct. The pressurization issues most houses have cause all sorts of discomfort, air quality problems and energy inefficiency.

All three of those measures will cost you less and pay you more than getting those last few SEER numbers. You might assume that since you're buying a Cadillac system that the contractor is going to take care of the stuff I mention as well. But amazingly that’s often not the case. Unless it's in writing and has been discussed, bet that it won't.

[Edited by Irascible on 02-20-2005 at 03:39 PM]

[duc dowg]

Originally posted by dash
The Infinity is the superior control system,uses the latest GE variable speed motor,and provides the best in indoor comfort.That said, both are very good systems,and a major improvement to your indoor comfort.

they are both great systems I have installed both of them

[James 3528]

The problem as I see it with these high SEER units in coastal climates is that they can't keep that high SEER rating when corrosion starts to work on them and the repair bills start to build. It is horrible in general that the accumulators are still made out of low grade metal .

[filterchanger]

repair bills are something the customer doesnt have to wory about for 10 years atleast with trane anyways,they have 10 year parts and labor warrantys

[pstu]

One thing I have heard said is SEER ratings are made at conditons NOT REALISTIC for hot-humid climates. Some people have advocated not going for ultra-high SEER as a result, I am not sure whether that is the right conclusion.

Is it true SEER is rated from a test made at outdoor temperature around 82 degrees? I would REALLY like to know how it will perform on our typical summer day, which is humid and way above that temperature.

Regards -- P.Student

[Edited by perpetual_student on 02-20-2005 at 07:42 PM]

[fat eddy]

Being that SEER rating is based upon a seasonal increnent and not a constant I would think that they use a mean temperature for testing and I would beleive that they would use a number like 82. JMHO based totally on assumption.

[docholiday]

EER is based on 95 outdoor 78 indoor temps which was based on full load conditions, SEER is tested the same way at 82 outside and 80 indoors, which in theory, was more of a part load, or more common condition. This also accounts for cycle losses in an attempt to keep it realistic. Now the higher indoor temp I find less realistic, but the playing field is level.

For those who shop for efficiency, SEER and EER should both be considered. You may find some High SEER units have pretty poor EER since they were merely desinged to achieve a high rating at the lower load. Integrity in advertising also needs to be looked at.

For instance lets assume a common match with 3 ton system on 60,000 btuh top of the line furnace.

Carrier 38TDB two speed 18 SEER unit.

38TDB036 on a 58MVP060 VS, 90+ furnace with the preferred coil CC5A/CD5AA036.

Well you get 15.00 SEER and an EER of 10.85

Lets try another brand same size.

Ruud UASL two speed 18 SEER unit.

Ruud UASL-036 tested with the UGFD-060 vs 90+ mod with the preferred coil RCQD3621A

In this case you get 16.30 SEER and an EER of 12.08

Now in fairness both are going to offer considerable comfort advantages and never achieve 18 SEER when using a gas furnace (both come close with 17 and 17.45 at a specific size.. the 18 SEER is acheived using an air handler only) but since SEER was the topic, lets assume comfort is also important and select the premium match at the sizes stated.

I dont have time to look them all up but feel free to post your favorit brand using the same criteria of ultra high efficiency 3 ton units and the premium furnace with a btuh value of 60,000 (yes 65 is ok) and the proper coil.

The same conditions are used for all manufacturers on all matches.

[dash]

Doc,

With a two speed, SEER and EER rating ,is it tested in high or low speed ??

[pstu]

Doc, you have given some info that I was hungry for. For S.Texas EER would be closer to the real world we have a lot of days where overnight temperatures only get a little below 80, and the dewpoint is high as well. SEER test conditions specify a certain dewpoint, don't they? It seems the standard SEER temperature might work nationwide but its usefulness for us is debatable.

If it would not be too much trouble, would you be able to look up EER for a slightly larger system: Trane XE-1200 3.5 ton AC with Am.Std. AUD-080-R9V4K (4.0T nominal airflow, 80K BTUH input). Or if you could assist with where to locate this kind of info myself, that would be great.

Thanks very much -- P.Student

[jpb2]

Doc, i work for a Ruud distributor have not seen anything on that model yet. Just the uara 16 seer. please send me a pdf or something to [no email addresses - site rules]. thanks !!!!!!

[Edited by BC1 on 02-21-2005 at 05:00 PM]

[James 3528]

Originally posted by jpb2
Doc, i work for a Ruud distributor have not seen anything on that model yet. Just the uara 16 seer. please send me a pdf or something to [no email addresses - site rules]. thanks !!!!!!

[Edited by BC1 on 02-21-2005 at 05:00 PM]

http://www.ruudac.com/products/Produ...ificModel=UASL

[docholiday]

[QUOTE]Originally posted by jpb2
[B]Doc, i work for a Ruud distributor have not seen anything on that model yet. Just the uara 16 seer. please send me a pdf or something to [no email addresses - site rules]. thanks !!!!!!

[Edited by docholiday on 02-22-2005 at 12:24 AM]

[docholiday]

QUOTE]Originally posted by jpb2
[B]Doc, i work for a Ruud distributor have not seen anything on that model yet. Just the uara 16 seer. please send me a pdf or something to [no email addresses - site rules]. thanks !!!!!!

[Edited by docholiday on 02-22-2005 at 07:54 AM]

[docholiday]

QUOTE]Originally posted by jpb2
Doc, i work for a Ruud distributor have not seen anything on that model yet. Just the uara 16 seer. please send me a pdf or something to [no email addresses - site rules]. thanks !!!!!!

[Edited by BC1 on 02-21-2005 at 05:00 PM] [/QUOTE]

Did you look on Rheemote?

Dash, I dont know off hand, I put the books away.... Did I quote one incorectly? I didnt mean to pic on the blue oval, I was just pointing out something to show the difference. My guess (and this is a guess) is that SEER is figured at low speed since the load is small enough and EER would be at full load.

p.Student, look it up on the ARI site or in the literature.

Really my point was for those of us in the business, SEER isn't everything. You need to look at EER, especially in the deep south and COP and HSPF for heat pumps.