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View Full Version : Trane v Amana; whole system v air handler only; heat pump v heat strip



TooDarnHot
04-17-2008, 04:02 PM
Newbie here, from coastal Florida, trying to get a handle on repairing on replacing all or a part of our central air system. Our house has 1600 sq feet under HVAC on 2nd floor, with garage and "bonus" rooms underneath (1st floor is not under central HVAC, as we're in a flood zone and the ground floor is uninsurable space). House was built in 1980; we bought it in 2005.

House has Trane HVAC equipment that predates us, a 2.5 ton 10 SEER condenser with heat pump from 2002, and an attic airhandler that dates from 1997 with a 5 KW "emergency" heat strip; the system is using R-22 freon. We understand that 2.5 ton is "borderline" for our size house.

Twice in recent months the system froze up on us, which may be in part because it is slightly undersized. The second time a slow leak in the evaporator coil was discovered; the technician topped up our freon as a temporary fix. We understand that our air handler is nearing the end of its useful life, but that the condenser has 5-7 years more useful life.

We wanted to fix our freezing problem while not overspending on things we don't need, or unnecessarily replacing components with significant remaining useful life. If we do go with a new system, which is probably not out first choice at present, we wanted a quieter condenser.

The tech suggested we meet with a sales guy, and after some discussion about the change in coolants after 2010 and our desire to invest efficiently, the sales guy suggested we consider one of three options, being:
(A) a entire new system using R-410A puron;
(B) an new air handler only (although we have some question as to whether it could handle R-22 now, and R-410A later when we replace the condenser in 5 years or so); or
(C) a new evaporator coil only, that hopefully would extend the useful life of our air handler to roughly that of the condenser (so that we'd replace the whole system at once, down the line).

We got 3 quotes from BBB-recommended, local installers, including the original firm.

Two quoted for similar Trane units for the entire system - being the XR13 4TWR3030 2.5 ton condenser heatpump, 4TEE3F31 variable speed OR 4TE3F30 standard airhandler, each with puron, digital thermostat and 8KW heatstrip, or alternatively if replacing the air handler only, a 2TEC3F30 standard AH (freon) with 8KW heatstrip. The new system was quoted at 14 SEER with the variable speed AH and 13 SEER with the standard. (They also quoted for replacing the evap coil with another unspecified Trane coil.) Other adds were to upgrade warranty from 10 year coil/condenser & 5 year parts, to 10 year all parts & labor, and to add a 5" "Nudia " (sp?) filter that needs to be changed only with the annual service.

The third firm (that had installed a Rheem in our neighbor's houser last year) quoted us for an Amana ASX-14 3 ton condenser with NO heat pump, with either a variable speed air handler or a standard one, digital thermostat, and a 10KW heat strip that would be the only heat source. He also quoted for an Amana air-handler only (that he said would work with the existing Trane condenser), and Trane evap coil only options, without giving precise model numbers, although the did say that the Amana AH could be used with either R-22 freon or R-410A puron, and flushed out and re-charged if we later replaced the condenser with a newer unit. He also said we could get a condenser unit with a heat pump for an extra $300-400. The new system was quoted at 15 SEER with the variable speed AH and 14 SEER with the standard.

The third firm's prices were $500-1000 lower than the better of the two Trane quotes. This firm also sells Trane, but said they'd have to raise the price by $1000 or so to quote Trane; their guy said he thought the two systems were equivalent, but that you pay for the name with Trane.

My questions:
1 - Is replacing the evap coil only likely to buy us another 5 years or so on the existing AH (the cheapest strategy) to line up the expected replacement dates of the condenser and AH? Will this alone help avoid the freezing issue?

2 - If we buy the AH only, can it be flushed and reused with R-410 5 years or so down the line at the end of the present condenser's useful life? Or does that depend on the specific AH installed? Also, will it help the freezing issue?

3 - If we buy an entire new system now, is the Trane $1000 (25%) better than the Amana? We are close to the Gulf and in a salt air environmment, if that matters. Is 3 ton a better size than 2.5 ton, given the freezing issue (or otherwise)? Which new condenser (Trane or Amana) is quieter?

4 - Can we effectively heat the house without a heatpump, with only a 10KW heat strip on the attic AH? We use the heat sporadically during cold snaps, maybe a total of 10-30 nights a year; rarely (maybe a few days a decade) does it get below 40 degrees F. If the heat strip alone is not enough, is the heat-pump add on fairly priced?

5 - What is a fair price for the two upgrades suggested by the Trane salesguy, being (A) 10 year pull parts/labor, and (B) once-a-year air filter?

6 - Am I missing anything in trying to make a cost-effective decision?

7 - What is your recommendation for the best bang for the buck?

Many thanks in advance!

beenthere
04-17-2008, 05:00 PM
The coil only should last as long as the current OD unit.
If you replace the current air handler, your stuck with that brand later for the OD unit. And it could be at a time, when another brand has their rebate program running.

When you do replace the entire syste. If your in an area that uses heat fairly often, you may want to stay with a heap pump. They cost less to use for heat then teh electric strip heaters.

Unless you only use heat one or 2 weeks a year.

RoBoTeq
04-17-2008, 08:10 PM
Your problems with this system are most likely due mostly to it being a Frankensystem (mismatched indoor and outdoor components). The best bet is to have whichever contractor you trust the most to install a complete system of whichever brand he/she recommends.

TooDarnHot
04-18-2008, 05:41 PM
Thanks, beenthere and RoBoTeq. I see that both of you are experienced guys that post frequently.

Sounds like neither of you is recommending replacing the air handler only. OK.

Beenthere is saying (I think), go with the evap coil only for now, which should extend the life of the AH long enough to replace the entire system later when the condenser goes (OD= condenser?).

RoBo is saying replace the whole system now, because it is mismatched (if I didn't say so clearly, all present equipment is Trane although from different years).

Question 1 - will replacing the coil only cure the freezing problem? If not, what will, short of replacing the entire system?

Question 2 - if I do replace the entire system now, should I go 2.5 ton or 3 ton, Trane or Amana?

Thx again guys.

TDH

BaldLoonie
04-18-2008, 06:12 PM
Post model #s to see if mismatched or not. Trane ran with the same air handlers for a long time so may not be a problem with the combo. An undersized system won't ice up just because it is undersized. Freeze up is low airflow, low refrigerant or both.

As for your questions:

1. Need to know why freezing! A good tech can find that out fairly quickly.

2. A load calc will tell you what size to get. Bigger is NOT better for Florida humidity control. Also most duct systems are undersized for what's there so if you just throw a 3 ton at it, you could make things worse not better. A good dealer, and they are hard to find, would first evaluate what the problem is with the current system, do a load calc to see what size you need, check to ducts to see if they can handle the needed size.

beenthere
04-18-2008, 07:29 PM
What the bald one said.

A coil only change out now, buys you the rest of the OD units lifespan.(in therory)

You might also want to see if there are any rebates on at this time that you might be able to take advantage of.
But if that OD unit is teh right size. Only being 6 years old, hard to justify changing it out.

Downeasthvac
04-18-2008, 07:50 PM
Replace the entire system now. R-22 systems will not be in production soon and there is no sense in spending good money by mismatching an already mismatched system. Spend the extra money, get an r-410a system, go with the variable speed because here in florida the extra humidity removal will benifet you and with the amana you will get a lifetime compressor and 10 year parts warranty with the full system replacement.

TooDarnHot
04-22-2008, 12:03 PM
Thanks again beenthere, and also thanks to baldloonie and downeasthvac.

A follow-up on the mismatched system thing, with existing equipment model numbers as one of the responders requested. The air handler is a 1997 Trane, model #TWE030C140F1; I wasn't able to determine tonnage. The condenser is a 2002 Trane XE-1000, model #TWR030C100A5; it is 2.5 ton. (I can post serial #s if needed.)

Questions:

1 - Is this considered a "mismatched" system, even though it is all Trane?

2 - The remaining alternatives are: (A) to replace the evap coil (with a Trane coil, 1 year warranty) in the air handler to extend its remaining useful life to roughly match that of the condenser (and then buy a new system in 5 years or so); or (B) replace the entire system now. What are the major pros and cons of each?

3 - If I choose 2(A), I'd pay roughly 40% the cost of a new air handler, and 20% the cost of a entire new system. Plus 5 years from now, new and more efficient systems than now will likely be available. So I'm leaning in that direction, unless there's real downside risk that I am not seeing. Comments?

4- Finally, is it fair to say that both the Trane system (XR13 4TWR3030, 2.5 ton) and the Amana system (ASX-14, 3 ton) are both good systems and roughly comparable in function, reliabilty, and longevity - even in a seaside environment - such that if one is significantly cheaper than the other, I should go with that one if I decide to replace the whole system now? (In that case, I'll have tonnage load recalculated either way to size system properly.)

Thanks again - you guys are great!

TDH

beenthere
04-22-2008, 01:40 PM
5 years from now, newer systems may be more efficient, but those more efficient systems will cost that much more to install.

I would change the coil. JMO.

alex_in_fl
04-22-2008, 09:35 PM
OLD: 1.5 ton and 4 ton Trane 10 SEER R22 Heatpumps
New: 1.5 ton Goodman 15 SEER R22 and 16 SEER 2 stage Amana R410a Heatpumps.

My electric bill dropped about $75 - $100 a month. Nothing wrong with buying the R22 unit. They stop making R22 but they don't stop selling it.

Trane and Amana are both good units. Robo gave good advice on picking a unit. One thing to consider. One company offers an as long as you own the unit and the home warranty on the outdoor compressor - the other doesn't.

Also, do not oversize and do get the heatpump. If you are slightly undersized add insulation or add film to windows and caulk around them. We love the 2 stage and live near Orlando.

Also, FPL offers rebate on entire unit changeouts (but you may not be on FPL).

TooDarnHot
04-23-2008, 05:02 PM
Thanks again, beenthere, and also alex in FL.

Based on all the input, I am going to replace the coil now only, and wait (I hope 5 years or so) until the condenser/compressor breaks down before replacing the whole system.

Also, several of the installers said that our return (we only have one) was undersized. Because of the configuation of our rafters and the common availability of certain sizes of air return filters, we are going to install a second return in another room.

The combination of increasing airflow with a 2nd return, and taking care of the freon leak with a new evap coil, should (if I understand you all correctly) solve or mitigate our freezing problem, not run our equipment as hard, and make our house more comfortable, while extending the useful life of our air handler to match that of the outside unit.

If I had to replace the system, now, I'd go with the Amana for the warranty; nothing against Trane.

I'm sure things will have changed when I do replace the entire system a few years down the line, and I will be back here then for your collective wisdom, if not before.

Many thanks to all who responded!

TDH

beenthere
04-23-2008, 05:10 PM
The lack of return could have been a big part of the freezing problem.
Unfortunately, we can't tell for sure from our screens.

alex_in_fl
04-23-2008, 05:19 PM
The lack of return could have been a big part of the freezing problem.
Unfortunately, we can't tell for sure from our screens.


You know, if you open his post, lick your finger and press it to the screen you can get a good idea of his return airflow.

:p:cool::p;);););)

beenthere
04-23-2008, 05:24 PM
You know, if you open his post, lick your finger and press it to the screen you can get a good idea of his return airflow.

:p:cool::p;);););)
LOL...

I thought that only worked on the A/C suction line. :)