Trane XB16 question
I need to replace a 14 year old Trane system and my current HVAC company is proposing a XB16 unit as part of the system. He says that the XB16 has the Climatuff compressor and is a high efficiency 2 stage unit.
I've looked at the Trane website and other literature but see no mention of this feature in the XB16 (the XB14 shows a climatuff compressor but no mention of 2 stage).
I know from reading this forum that Trane is doing some major changes in the product line but wanted to get another opinion on this suggestion.
Does the XB16 have the 2 stage Climatuff compressor? I live in Texas and it gets hot during the summers and want to make sure I get a good system
thanks for the help
Were you given model #s for the equipment (indoor and outdoor)? The 4ttb6061 uses a 2-stage scroll. Are you replacing the indoor unit (furnace and coil or air handler with electric heat) also?
I don't have specific model numbers for the units but can probably get them from the sales guy on Monday. I am planning to replace the indoor and outdoor units.
the most details I have is the XB16 HE 2 stage AC unit and a variable speed XV80 gas furnace. It's a 5 ton unit and the system is being quoted at 16 seer
Trane built the XB16 to compete with other equipment manfactors where they were losing money to which was the mid range market.
You need to ask the installing company for model #'s of outdoor unit, indoor furnace, and coil. As Ryan pointed out if the outdoor model # is 4TTB6061 then it will have (2) stage scroll compressor if not it will have single stage compressor.
Personally I have never installed a XB16 for know other reason then its not the unit I suggest to my customers. Nothing wrong with it but when reviewing over system options I prefer the XR16 single stage which in your case when looking at a (5) ton 4TTR6061 also has the (2) stage scroll compressor. If it was a smaller sized system from 2,3,4 I what recommed a XR17 which is (2) stage scroll in all sizes included (5) ton.
Something to be sure of is the model # if it is the 4TTB6061 it will have the exact same compressor as a XR16 with the 6061 in the model # or a XR17. There is no Diffrance other then color of the outdoor unit which is tan (XB16) compaired to medium grey of (XR16-17) warranties are the same.
Did the contractor perform a load cal do determine the size of the equipment or just go by what you have? Even though the existing system has ran 14 years doesn't mean it sized properly. Often hvac companies do a rule of thumb to size equipment. From 300-600 square foot per ton which is a guess and often leads to oversized equipment with undersized ductwork as the same rules of thumbs were used for sizing the duct system.
Before you sign off on the install get full model #'s of each peace of equipment, scope of the work and load cal in writing. I understand you live in Texas I am a neighbor to you in Louisiana and we have the same weather which is hot in the summer and mild to cold in the winter.
thanks much for the details on the Trane units. I will get the specific model numbers for the units before signing off on anything. The person did say that Trane was doing making these types of solutions available to compete in other markets like you suggest.
I don't believe there was any load calculations done and they are just replacing what's already here. This will be another detail I will add to the list for my HVAC guy.
I really do appreciate the insight from folks like yourselves - I'm obviously not a professional in this area and it's great to have a way to get clarifications and directions from knowledgeable people.
Glad to help. Please post back the outcome or any other questions that come up. There are many systems avaiable to contractors and customers the truck is to find the one that meets your needs and will provide you comfort, electric saving etc...
Originally Posted by loafy
Duckman06 and RyanHughs,
here is the details on the proposal from my HVAC guy: for the coil it's a TXC-B-5-SUB-1E ComfortCoil and the 2 stage TUD2C100B9V-SUB-1B variable speed furnace along with the 4TTB6061A-SUB-1 2 stage condenser. He sent me the spec sheets but I can't figure out how to include the pdf's.
as for the load calculation, I confirmed that they are doing a like-for-like replacement. When asked about doing a detail load calc, he said that even if they did the work and it showed something less than a 5 ton replacement unit that the savings would be minimal at best given the 2 floors I have with the open great room.
hope this helps - appreciate all the help and direction!
They are still guessing on the size you need by not doing a load calc. There are many systems out there that were never sized correctly (typically oversized) to begin with. It's not all about energy savings, but mostly for the greater comfort that properly sized equipment provides, especially with regards to humidity control in the summer. At least the model you are considering is a 2-stage unit, but that doesn't give a good reason to oversize. 2-stage units work much better when they are sized properly; otherwise they end up running primarily in low stage.
The coil model you gave isn't valid -- looks like the name of the .pdf submittal document. There should be a model number on there somewhere that looks like 4TXCC***. Then we can verify that it is a properly matched system per AHRI.
Lastly, they should verify your ductwork size is adequate for the full airflow required by a 5 ton system. Variable speed systems can be loud when the ductwork is undersized, which can be avoided altogether with properly sized equipment and/or proposed modifications to increase supply/return capacity.
2 more questions if you don't mind-
1. What was the original cause for failure/need for replacement?
2. On the hottest days (and I know it gets hot in TX), did the old 5 ton system have to run constantly to maintain temperature, or was it able to cycle off?
Last edited by RyanHughes; 01-06-2014 at 05:40 PM.
I checked the spec sheet for the coil and there are 4 models:
I have an email into my guy asking which model is in the quote.
on the load calc topic - how much of an effort is it to preform such work? is it calculations or physical work? do they have to inspect all the duct work?
The reason for the replacement is that I was told I have a cracked heat exchanger.
During the last summer when it was really hot the AC would run but not for extended periods of time. The unit has always been better at cooling then heating. In fact, during the summer I feel cold when the AC is blowing on me (not my wife of course). During the cold days like now, the heater blows a lot more more and the house still feels chilly.
4TXCD063BC3HCB is the coil the company is proposing.
TXC-B-5-SUB-1E for the furnace
4TTB6061A for the ac unit
That is a proper match (AHRI certificate ref. #5823447). www.ahridirectory.org - 13 EER / 16 SEER
With the 5 ton two-stage XB16, low stage is about 75% of total capacity. So the concern is that on most days, even low stage could be more capacity than you need, not giving you the long cycle times you want with a 2-stage system for more even temperatures and better humidity control. But no reliable way to know without a load calculation. The fact that your older 5 ton system did not run extended cycles on the hottest days indicates that a 5 ton system is oversized. The cracked heat exchanger, if it is indeed cracked, could be due to insufficient airflow across the heat exchanger (undersized ductwork). The variable speed blower in the XV80 will actually work harder to move the necessary air, and can be noisy. You say you were never warm enough in the winter, have to wonder if the burners were cycling off on the high temp safety limit. Was it actually maintaining temperature in the winter? With a 2-stage furnace like the XV80, you should get more even heating and better comfort with the 2-stage heat operation. The furnace will almost certainly (and necessarily) be oversized to get a blower motor capable of supporting a 5 ton outdoor unit, unless 5 tons is not what you need and you can downsize.
My advice is to not move forward without a load calc. As far as what it entails- it will involve collecting information about the home's building properties (insulation, windows, room sizes, etc.). There are good software programs that competent professionals use allowing them to be done in reasonable periods of time depending on the circumstances (1-2 hrs or less). Many companies do not perform them on routine estimates, knowing they have no guarantee of a sale. But this often results in improperly sized equipment which you, the consumer, pay for in the long run in terms of comfort and realized efficiency.
Agreed!!! They are guessing and just sizing per your orginal unit which is more then lickey oversized on both the a/c and furnace?
Originally Posted by RyanHughes
From what you posted it draws even more concern that the proper sized system for your home has not been found. The furnace while (2) stage still appers to over sized and the a/c systen might be a while? Only a load cal can tell us all the truth!