I have been reading the site for a while and searching for info on the various products and found lots of good into, but nothing that asks my exact question .

My 2.5 ton heat pump compressor has died and the whole system is really old (air handler is a GE maybe 25 years old and still going), so time to move on to something new and more efficient. My problem is I have limited places to install the outside unit so I probably need to put it back where the dead system sits. The second part of the problems is the liquid line is 5/16" and is run in between the two floors of the house - both finished with no access to replace the lines without tearing out the ceiling in the basement.. I got quotes from several contractors but almost all are high or not desirable due to the need to relocated the compressor and run new lines and power. However, both Trane and Rheem / Ruud make 2.5 ton 410a systems that can work fine with the 5/16" line. So unless I want to pay a lot to move it to a less desirable location those are my options. The prices for these two systems are very close.

Trane 2.5 ton XR13 + 4TEE handler w/ECM motor = 14 SEER "in theory" using 410a

Rheem 2.5 RPNL (13 SEER) + 3.0 ton RHLL handler w/X-13 motor = 15 SEER "in theory" using 410a

I can also get the 2.5 ton RPNL heat pump with the 3.0 ton RHKL handler and the ECM variable speed motor for about the same price, 14 SEER for that combo.

I think the warranty is the same for any of these and the cost is in the same ballpark - within a couple of hundred.

The Trane has the variable speed ECM motor but in the 2.5 ton sizes does not have the scroll compressor.

The Rheem has the X-13 very efficient motor, but it is single speed with no ramp up or stop delay settings. Copeland scroll compressor.

The Rheem handler with the ECM motor is less efficient (SEER rating) than the X-13 Rheem and the same as the Trane and has the ability to be run via a humidistat and has settings for slow or full speed when in this mode. The Trane may as well, but I can't find the install guide for the Trane online - you can find EVERYTHING online for Rheem, which is nice. Scroll compressor on this one too.

In the past I have run the fan all the time to help balance out the temps between the floors and the rooms, so part of me says the Rheem with the X-13 is the way to go. That said, I have never had a variable speed blower before or a humidistat so I do not know what I am missing? If I run the fan all the time with any of these systems I will save a good bit of juice based on the specs I could find.

The quotes as written do not include a humidistat on the ECM motor systems, but I am sure both contractors would be glad to add that to the quote and install it with the rest of the stuff. It may make the installed a good bit cost higher than getting the X-13 system depending on the price of the stat and the need to run a new t-stat to handler control cable.

So is the "big name" Trane brand worth getting even if no scroll compressor? The X-13 motor specs show it is more efficient than the ECM but is just a tap speed motor while the ECM does the constant air flow thing and the spool up and delay stop and either system SHOULD be made to work with a humidistat. Some folks have told me that the ECM motor is better (than a standard motor anyway) even without a humidity sensor since the ramp up and optional delay to stop along with the constant CFM are all pluses even without the run to dehumidify option.

I was also quoted a Trane XL14i with the same handler with a 14 SEER but it is a LOT more (25%) than the other systems but I don't see a lot of improvement over the other systems for the extra money.

I don't think any of the 3 is a wrong choice in the bunch given how much more efficient this will be over the old system and given my line size and placement limits.

Thoughts from the pros?