Trane furnace models?

I'm looking at a new furnace and local dealer installs Trane.

I'm looking at 3 models -

S9V2-VS
XV95
XC95m

So the two 95s seem the main difference is the modulating m model.
The S9V2-VS is a condensing model but not sure what difference is between the models? What is different with the s series?
Thanks

 

I don't have sufficient famiarity with Trane's lineup to get into the nuances,, but models differences aside, be sure to run a fuel use load calculation for sizing the thing if you want it to modulate and deliver the best comfort.

Most existing furnaces out there are 3x or more oversized for the actual loads (as if the next ice age were expected). ASHRAE recommends 1.4x oversizing from the load at the 99% outside design temperature, which is enough to cover cold snaps and allow overnight setback strategies with reasonable recovery times. If the burner is 3x oversized and the minimum fire is still above your design load there is nothing to be gained with a modulating or multi-stage furnace compared to a cheaper but right-sized furnace. A right sized furnace will be running more than a 2/3 duty cycle during the coldest weather, which to some feels like it's "struggling to keep up", but what it's actually doing is keeping you more comfortable with those long run cycles, rather than delivering a hot flash followed by the chill that happens with oversized equipment.

 

One thing available on many furnaces is a variable speed fan. Trane (used to) use a 16-speed fan motor. This is nice in the winter since it starts slowly until the ducts get warmed up preventing that initial cold blast, then depending on how long it needs to run, will start to ramp up. At the end, it will ramp down, extracting the heat you paid for from the heat exchanger. In the summer, by starting out slower, the air passes over the cooling coil slower, extracting LOTS more moisture, and will then speed up if needed. It will make a HUGE difference in how well it dehumidifies the house for less power and cycling. I generally leave my fan running most of the time, and it does so at the lowest speed. This helps to keep the air from being stratified, runs it through the filter more often, but because it is so slow, you can't hear it or really notice a breeze. Single speed (or even 2-speed) fans will take lots more power and result in more noise in the process. With the slow ramp up and down, you don't really notice that the fan is running until it gets to high speed, and generally, it doesn't need to get there very often.

 

The SV9V2-VS had a 2 stage burner as does the XV95 .

The XC95m has a fully modulating burner with a min-firing rate 40% of it's maximum. Sized correctly it would modulate most of the time during the winter at low quiet comfort nearly 100% duty cycle, but oversized by 3x almost never.