Choice between XL15i or XL16i??
Hi all, thanks for reading my post. I’m currently working through the decision details of a furnace/air-conditioner install in my 21 year-old house in Omaha, NE with a very helpful company. The house is 2-story with finished basement, with a total of 4,000 sq. ft. The system will be a Trane.
The Manual J calculations are being finished. I’ve decided on a Trane XV80 VARI-2STG TUD100R9V5K(C) for the furnace. I’m also getting the HW VisionPro IAQ stat.
My problem is choosing the a/c. I’ve narrowed the choice down to either the XL16i or the XL15i. The 19i is not in the running.
My dilemma is that dehumidification is a somewhat significant issue with my wife and I. But it’s short of buying a whole-house dehumidifier (which I’m not necessarily against either). In addition to the hot, humid summer months, for a multitude of reasons we’d definitely like to run the a/c in the spring and fall when the outside temps are moderate but the humidity is still high.
I’ve read on this forum that many of the experts are less than impressed with the 16i because, if I understand correctly, the dehumidifying capability is less than expected due to the inability to do dehumidify-on-demand because Trane has implemented a funky wiring scheme for the 16i. In addition, the 1st stage/2nd stage compressor is 70/100 (according to the Trane dealer), and the split is not significant enough to see a major difference considering the cost.
Ordinarily, to my inexperienced mind, the 2-stage compressor of the 16i would seem to offer a better chance at dehumidification, EXCEPT for it’s apparent peculiar drawbacks. The 15i, according to what I’ve read on the forum, is a solid performer even with the single-stage compressor. As suggested by the experts in other threads, I could chose the 15i and let the stat and variable-speed blower do the dehumidifying job. Will that work as well in the spring/fall months?
Do any of the professionals here have an opinion on which a/c unit they’d chose under the circumstances? In your experienced opinions, is it a toss-up, or given the circumstances, is one better than the other.
Thanks in advance.
I've actually heard the first stage of the XL16i to be more around 80% on first stage, making only a small difference between high and low. 67% is the low stage capacity of the compressor, but the coils affect capacity as well, making it more around 75-80%. That along with the inability to dehumidify on demand with the IAQ would make the XL15i an easy choice in my opinion. Good unit. I've seen it said on these forums that the XL16i has a low latent (humidity removal) capacity in first stage to begin with, but I can't say that with full certainty without the specific data to support it.
Hi Ryan, thanks for your response.
Originally Posted by RyanHughes
Yes, I asked the Trane rep about the low stage capacity of the 16i (because of the discussions here) and he claimed 70%, so I didn't argue. But I do remember reading your post (and others) about it being closer to 80%.
I do also remember the thread about the low latent capacity in 16i first stage but apparently Trane doesn't offer that data or hasn't been located.
I asked the Trane rep about the DoD/IAQ thing (as best I could) and he knew nothing about it. Probably my fault, though.
Thanks-you for the quick reply!
The actual capacity on low with the unloading scroll is more like 75-80% in real life. They say a 67% figure on low but cooling effect is higher. Not sure the technical explanation.
Because of the screwy way the 16i has to be wired on a Trane furnace, you cannot use dehumidify on demand feature. If I were doing it, I'd go the 15i myself. Or really I'd go the 15i heat pump. Your climate and I would suspect decent electric rates would be a good place for dual fuel. And the R410a version of the 15i is Trane's best performing pump.
Hi BaldLoonie, thanks.
The electric rates are fairly decent here so that's a good idea. I"ll crunch the numbers.
Appreciate the suggestion.
The 16i's compressor is 67% in first stage.
But, due to the large condenser and evap coil, along with the high air flow, you have closer to if not 80% cooling capacity. With a high sensible capacity.
The 15i, with a VS blower, should give you better moisture removal in the milder temps then the 16i. The 15i will have a lower coil temp at 80% blower speed, then the 16i does in first stage at 80% blower speed.
And if you go with dual fuel, you'll get more heat from the 15i.
Ryan and beenthere...and others
Thanks a million guys, the link and expert opinions have help immensely.
Tomorrow morning I meet with the Trane gentleman and I'll have my decision ready for him and we can put a deal together, I think.
Everyone from the HVAC company has been very helpful and patient with me, but it really helps to get independent expert opinions.
Y'all are very kind indeed.
you should consider the Trane 19i or American Standard 18 seer if you have special humidity needs!
or consider other 2 stage systems (besides the 16i)
Further Explain Dehumidify on Demand (DoD)
You state: "Because of the screwy way the 16i has to be wired on a Trane furnace, you cannot use dehumidify on demand (DoD) feature"
Now my xL16i is wired to TCONT 803 which has the Dehumidification Droop feature that allows for 3* droop below setpoint for dehumidification. So, Tstat allows me to set a humidity level and AC will be used to reduce humidity.
For sake of discussion we are not talking about having a whole house dehu installed, just simply using AC for dehu control which has its limits and negatives etc. And for the moment lets set aside performace issues of 1-stage 15i vs 2-stage 16i, Trane vs Carrier, coil upsizing vs. downsizing. Once its clear what DoD means, performance can be discussed.
So simply put, when you use the phrase DoD, how would that differ in other systems from what the Trane TCON803/Honeywell TH8321 does using humidification droop. Simply trying to understand the meaning of various differing phrases you pros use.
From the HW manual: The thermostat monitors humidity. When humidity increases, the thermostat runs the air conditioner longer to reduce humidity (up to 3°F below your cooling temperature setting).
unlike 99% of all other variable speed air/handlers, the 16i does not have the ability to slow the blower down to dehumidify!
Originally Posted by wraujr
and this is directly related to the way the control system is wired up!
Yes, dehumidify on demand is a feature of the IAQ stat and almost every variable speed blower system except with the 16i where the stat tells the blower to slow down if it is cooling and the humidity is high. This really increases the moisture sucking of the system. The IAQ will also overcool if the humidity is high, that's the only thing the 803/8321 can do.
Yes, I understand that. The question is what defines DoD. I'll take a stab at it by saying.
- Hstat commands AC to run and remove humidity
or is it
- Hstat commands AC to run, but reduce blower speed to provide humidty removal.
or is it
- Hstat commands AC to run, in 1 stage with reduced blower speed to provide humidty removal.
When you say something doesn't do DoD i am just trying to understand what your definition of DoD is. In my mind, all of the above are DoD except that some are more efficient than others. My point is that with the TCONT803/xL16i the user can set a humidity level and the system will use the AC to control the humidity level. Isn't that DoD??? There is no argument that it may not be the "best" performance solution. But quite frankly, based on other posts by the pros, all the variables that go into calculating the "best" performance make it pretty hard to say with 100% certainty which is the best....
OD unit/ID coil selection
CFMs due to blower speed selection
Resulting run time
Cost of electricity
All of the above would add up to quite a "science experiment" to compare two systems. Of course, "typically" one can say one approach will yield better results, which I certainly agree is valid and based on the pros personal experience, etc. I am not trying to change anyone's opinion of anything. Just trying to understand what goes into their thought process.